* [PATCH v12 07/13] unwind_user: Stop when reaching an outermost frame
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
Add an indication for an outermost frame to the unwind user frame
structure and stop unwinding when reaching an outermost frame.
This will be used by unwind user sframe, as SFrame may represent an
undefined return address as indication for an outermost frame.
Cc: Steven Rostedt <rostedt@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Adjust to Peter's tip perf/core commit ae25884ad749 ("unwind_user/x86:
Teach FP unwind about start of function").
Changes in v11:
- New patch.
arch/x86/include/asm/unwind_user.h | 6 ++++--
include/linux/unwind_user_types.h | 1 +
kernel/unwind/user.c | 6 ++++++
3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/unwind_user.h b/arch/x86/include/asm/unwind_user.h
index 12064284bc4e..f9a1c460150d 100644
--- a/arch/x86/include/asm/unwind_user.h
+++ b/arch/x86/include/asm/unwind_user.h
@@ -11,13 +11,15 @@
.cfa_off = 2*(ws), \
.ra_off = -1*(ws), \
.fp_off = -2*(ws), \
- .use_fp = true,
+ .use_fp = true, \
+ .outermost = false,
#define ARCH_INIT_USER_FP_ENTRY_FRAME(ws) \
.cfa_off = 1*(ws), \
.ra_off = -1*(ws), \
.fp_off = 0, \
- .use_fp = false,
+ .use_fp = false, \
+ .outermost = false,
static inline int unwind_user_word_size(struct pt_regs *regs)
{
diff --git a/include/linux/unwind_user_types.h b/include/linux/unwind_user_types.h
index 43e4b160883f..616cc5ee4586 100644
--- a/include/linux/unwind_user_types.h
+++ b/include/linux/unwind_user_types.h
@@ -32,6 +32,7 @@ struct unwind_user_frame {
s32 ra_off;
s32 fp_off;
bool use_fp;
+ bool outermost;
};
struct unwind_user_state {
diff --git a/kernel/unwind/user.c b/kernel/unwind/user.c
index 7644ab9f6a61..d053295b1f7e 100644
--- a/kernel/unwind/user.c
+++ b/kernel/unwind/user.c
@@ -32,6 +32,12 @@ static int unwind_user_next_common(struct unwind_user_state *state,
{
unsigned long cfa, fp, ra;
+ /* Stop unwinding when reaching an outermost frame. */
+ if (frame->outermost) {
+ state->done = true;
+ return 0;
+ }
+
if (frame->use_fp) {
if (state->fp < state->sp)
return -EINVAL;
--
2.48.1
^ permalink raw reply related
* [PATCH v12 09/13] unwind_user/sframe/x86: Enable sframe unwinding on x86
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
The x86 SFrame V2 implementation works fairly well, starting with
binutils 2.45 with PC-relative SFrame FDE function start address
encoding (though some issues are getting fixed in later versions).
Enable it.
[ Jens Remus: Reword commit message for SFrame V2 PC-relative FDE
function start address encoding, starting with binutils 2.45. ]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Reword commit message for SFrame V2 PC-relative FDE function start
address encoding, starting with binutils 2.45.
arch/x86/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c4c21e8d0772..0e9a9c5ca0bc 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -299,6 +299,7 @@ config X86
select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_UNWIND_USER_FP if X86_64
+ select HAVE_UNWIND_USER_SFRAME if X86_64
select HAVE_USER_RETURN_NOTIFIER
select HAVE_GENERIC_VDSO
select VDSO_GETRANDOM if X86_64
--
2.48.1
^ permalink raw reply related
* [PATCH v12 13/13] unwind_user/sframe: Add prctl() interface for registering .sframe sections
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
The kernel doesn't have direct visibility to the ELF contents of shared
libraries. Add some prctl() interfaces which allow glibc to tell the
kernel where to find .sframe sections.
[
This adds an interface for prctl() for testing loading of sframes for
libraries. But this interface should really be a system call. This patch
is for testing purposes only and should not be applied to mainline.
]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
include/uapi/linux/prctl.h | 6 +++++-
kernel/sys.c | 9 +++++++++
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index 51c4e8c82b1e..91d2c9eb3aa3 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h
@@ -368,7 +368,7 @@ struct prctl_mm_map {
* configuration. All bits may be locked via this call, including
* undefined bits.
*/
-#define PR_LOCK_SHADOW_STACK_STATUS 76
+#define PR_LOCK_SHADOW_STACK_STATUS 76
/*
* Controls the mode of timer_create() for CRIU restore operations.
@@ -386,4 +386,8 @@ struct prctl_mm_map {
# define PR_FUTEX_HASH_SET_SLOTS 1
# define PR_FUTEX_HASH_GET_SLOTS 2
+/* SFRAME management */
+#define PR_ADD_SFRAME 79
+#define PR_REMOVE_SFRAME 80
+
#endif /* _LINUX_PRCTL_H */
diff --git a/kernel/sys.c b/kernel/sys.c
index 8b58eece4e58..ea088b643eb4 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -65,6 +65,7 @@
#include <linux/rcupdate.h>
#include <linux/uidgid.h>
#include <linux/cred.h>
+#include <linux/sframe.h>
#include <linux/nospec.h>
@@ -2868,6 +2869,14 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
case PR_FUTEX_HASH:
error = futex_hash_prctl(arg2, arg3, arg4);
break;
+ case PR_ADD_SFRAME:
+ error = sframe_add_section(arg2, arg3, arg4, arg5);
+ break;
+ case PR_REMOVE_SFRAME:
+ if (arg3 || arg4 || arg5)
+ return -EINVAL;
+ error = sframe_remove_section(arg2);
+ break;
default:
trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5);
error = -EINVAL;
--
2.48.1
^ permalink raw reply related
* [PATCH v12 05/13] unwind_user/sframe: Detect .sframe sections in executables
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
When loading an ELF executable, automatically detect an .sframe section
and associate it with the mm_struct.
[ Jens Remus: Fix checkpatch warning "braces {} are not necessary for
single statement blocks". ]
Cc: linux-mm@kvack.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Fix checkpatch warning "braces {} are not necessary for single
statement blocks".
fs/binfmt_elf.c | 48 +++++++++++++++++++++++++++++++++++++---
include/uapi/linux/elf.h | 1 +
2 files changed, 46 insertions(+), 3 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 3eb734c192e9..fc6ecb4d239e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -47,6 +47,7 @@
#include <linux/dax.h>
#include <linux/uaccess.h>
#include <uapi/linux/rseq.h>
+#include <linux/sframe.h>
#include <asm/param.h>
#include <asm/page.h>
@@ -637,6 +638,21 @@ static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state,
return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp);
}
+static void elf_add_sframe(struct elf_phdr *text, struct elf_phdr *sframe,
+ unsigned long base_addr)
+{
+ unsigned long sframe_start, sframe_end, text_start, text_end;
+
+ sframe_start = base_addr + sframe->p_vaddr;
+ sframe_end = sframe_start + sframe->p_memsz;
+
+ text_start = base_addr + text->p_vaddr;
+ text_end = text_start + text->p_memsz;
+
+ /* Ignore return value, sframe section isn't critical */
+ sframe_add_section(sframe_start, sframe_end, text_start, text_end);
+}
+
/* This is much more generalized than the library routine read function,
so we keep this separate. Technically the library read function
is only provided so that we can read a.out libraries that have
@@ -647,7 +663,7 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
unsigned long no_base, struct elf_phdr *interp_elf_phdata,
struct arch_elf_state *arch_state)
{
- struct elf_phdr *eppnt;
+ struct elf_phdr *eppnt, *sframe_phdr = NULL;
unsigned long load_addr = 0;
int load_addr_set = 0;
unsigned long error = ~0UL;
@@ -673,7 +689,8 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
eppnt = interp_elf_phdata;
for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
- if (eppnt->p_type == PT_LOAD) {
+ switch (eppnt->p_type) {
+ case PT_LOAD: {
int elf_type = MAP_PRIVATE;
int elf_prot = make_prot(eppnt->p_flags, arch_state,
true, true);
@@ -712,6 +729,19 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
error = -ENOMEM;
goto out;
}
+ break;
+ }
+ case PT_GNU_SFRAME:
+ sframe_phdr = eppnt;
+ break;
+ }
+ }
+
+ if (sframe_phdr) {
+ eppnt = interp_elf_phdata;
+ for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
+ if (eppnt->p_flags & PF_X)
+ elf_add_sframe(eppnt, sframe_phdr, load_addr);
}
}
@@ -836,7 +866,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
int first_pt_load = 1;
unsigned long error;
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
- struct elf_phdr *elf_property_phdata = NULL;
+ struct elf_phdr *elf_property_phdata = NULL, *sframe_phdr = NULL;
unsigned long elf_brk;
bool brk_moved = false;
int retval, i;
@@ -945,6 +975,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
executable_stack = EXSTACK_DISABLE_X;
break;
+ case PT_GNU_SFRAME:
+ sframe_phdr = elf_ppnt;
+ break;
+
case PT_LOPROC ... PT_HIPROC:
retval = arch_elf_pt_proc(elf_ex, elf_ppnt,
bprm->file, false,
@@ -1242,6 +1276,14 @@ static int load_elf_binary(struct linux_binprm *bprm)
elf_brk = k;
}
+ if (sframe_phdr) {
+ for (i = 0, elf_ppnt = elf_phdata;
+ i < elf_ex->e_phnum; i++, elf_ppnt++) {
+ if ((elf_ppnt->p_flags & PF_X))
+ elf_add_sframe(elf_ppnt, sframe_phdr, load_bias);
+ }
+ }
+
e_entry = elf_ex->e_entry + load_bias;
phdr_addr += load_bias;
elf_brk += load_bias;
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 819ded2d39de..92c16c94fca8 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -41,6 +41,7 @@ typedef __u16 Elf64_Versym;
#define PT_GNU_STACK (PT_LOOS + 0x474e551)
#define PT_GNU_RELRO (PT_LOOS + 0x474e552)
#define PT_GNU_PROPERTY (PT_LOOS + 0x474e553)
+#define PT_GNU_SFRAME (PT_LOOS + 0x474e554)
/* ARM MTE memory tag segment type */
--
2.48.1
^ permalink raw reply related
* [PATCH v12 02/13] unwind_user/sframe: Store .sframe section data in per-mm maple tree
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
Associate an .sframe section with its mm by adding it to a per-mm maple
tree which is indexed by the corresponding text address range. A single
.sframe section can be associated with multiple text ranges.
[ Jens Remus: Minor cleanups. Reword commit subject/message. ]
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: x86@kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Add include of linux/mm_types.h and variable sframe_mt from
"unwind_user/sframe: Add support for reading .sframe headers".
- Reword commit subject/message to consistently use ".sframe" when
referring to the section.
arch/x86/include/asm/mmu.h | 2 +-
include/linux/mm_types.h | 3 ++
include/linux/sframe.h | 15 ++++++++++
kernel/fork.c | 10 +++++++
kernel/unwind/sframe.c | 56 ++++++++++++++++++++++++++++++++++++--
mm/init-mm.c | 2 ++
6 files changed, 84 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 0fe9c569d171..227a32899a59 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -87,7 +87,7 @@ typedef struct {
.context = { \
.ctx_id = 1, \
.lock = __MUTEX_INITIALIZER(mm.context.lock), \
- }
+ },
void leave_mm(void);
#define leave_mm leave_mm
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 90e5790c318f..01e2cffbd84e 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -1227,6 +1227,9 @@ struct mm_struct {
#ifdef CONFIG_MM_ID
mm_id_t mm_id;
#endif /* CONFIG_MM_ID */
+#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME
+ struct maple_tree sframe_mt;
+#endif
} __randomize_layout;
/*
diff --git a/include/linux/sframe.h b/include/linux/sframe.h
index 0642595534f9..7ea6a97ed8af 100644
--- a/include/linux/sframe.h
+++ b/include/linux/sframe.h
@@ -2,6 +2,8 @@
#ifndef _LINUX_SFRAME_H
#define _LINUX_SFRAME_H
+#include <linux/mm_types.h>
+
#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME
struct sframe_section {
@@ -19,18 +21,31 @@ struct sframe_section {
signed char fp_off;
};
+#define INIT_MM_SFRAME .sframe_mt = MTREE_INIT(sframe_mt, 0),
+extern void sframe_free_mm(struct mm_struct *mm);
+
extern int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
unsigned long text_start, unsigned long text_end);
extern int sframe_remove_section(unsigned long sframe_addr);
+static inline bool current_has_sframe(void)
+{
+ struct mm_struct *mm = current->mm;
+
+ return mm && !mtree_empty(&mm->sframe_mt);
+}
+
#else /* !CONFIG_HAVE_UNWIND_USER_SFRAME */
+#define INIT_MM_SFRAME
+static inline void sframe_free_mm(struct mm_struct *mm) {}
static inline int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
unsigned long text_start, unsigned long text_end)
{
return -ENOSYS;
}
static inline int sframe_remove_section(unsigned long sframe_addr) { return -ENOSYS; }
+static inline bool current_has_sframe(void) { return false; }
#endif /* CONFIG_HAVE_UNWIND_USER_SFRAME */
diff --git a/kernel/fork.c b/kernel/fork.c
index 3da0f08615a9..15c24411dd7d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -106,6 +106,7 @@
#include <linux/pidfs.h>
#include <linux/tick.h>
#include <linux/unwind_deferred.h>
+#include <linux/sframe.h>
#include <asm/pgalloc.h>
#include <linux/uaccess.h>
@@ -689,6 +690,7 @@ void __mmdrop(struct mm_struct *mm)
mm_pasid_drop(mm);
mm_destroy_cid(mm);
percpu_counter_destroy_many(mm->rss_stat, NR_MM_COUNTERS);
+ sframe_free_mm(mm);
free_mm(mm);
}
@@ -1027,6 +1029,13 @@ static void mmap_init_lock(struct mm_struct *mm)
#endif
}
+static void mm_init_sframe(struct mm_struct *mm)
+{
+#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME
+ mt_init(&mm->sframe_mt);
+#endif
+}
+
static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
struct user_namespace *user_ns)
{
@@ -1055,6 +1064,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
mm->pmd_huge_pte = NULL;
#endif
mm_init_uprobes_state(mm);
+ mm_init_sframe(mm);
hugetlb_count_init(mm);
mm_flags_clear_all(mm);
diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index 26bb16f76a8d..149ce70e4229 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -81,6 +81,7 @@ static int sframe_read_header(struct sframe_section *sec)
int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
unsigned long text_start, unsigned long text_end)
{
+ struct maple_tree *sframe_mt = ¤t->mm->sframe_mt;
struct vm_area_struct *sframe_vma, *text_vma;
struct mm_struct *mm = current->mm;
struct sframe_section *sec;
@@ -122,15 +123,64 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
if (ret)
goto err_free;
- /* TODO nowhere to store it yet - just free it and return an error */
- ret = -ENOSYS;
+ ret = mtree_insert_range(sframe_mt, sec->text_start, sec->text_end, sec, GFP_KERNEL);
+ if (ret) {
+ dbg("mtree_insert_range failed: text=%lx-%lx\n",
+ sec->text_start, sec->text_end);
+ goto err_free;
+ }
+
+ return 0;
err_free:
free_section(sec);
return ret;
}
+static int __sframe_remove_section(struct mm_struct *mm,
+ struct sframe_section *sec)
+{
+ if (!mtree_erase(&mm->sframe_mt, sec->text_start)) {
+ dbg("mtree_erase failed: text=%lx\n", sec->text_start);
+ return -EINVAL;
+ }
+
+ free_section(sec);
+
+ return 0;
+}
+
int sframe_remove_section(unsigned long sframe_start)
{
- return -ENOSYS;
+ struct mm_struct *mm = current->mm;
+ struct sframe_section *sec;
+ unsigned long index = 0;
+ bool found = false;
+ int ret = 0;
+
+ mt_for_each(&mm->sframe_mt, sec, index, ULONG_MAX) {
+ if (sec->sframe_start == sframe_start) {
+ found = true;
+ ret |= __sframe_remove_section(mm, sec);
+ }
+ }
+
+ if (!found || ret)
+ return -EINVAL;
+
+ return 0;
+}
+
+void sframe_free_mm(struct mm_struct *mm)
+{
+ struct sframe_section *sec;
+ unsigned long index = 0;
+
+ if (!mm)
+ return;
+
+ mt_for_each(&mm->sframe_mt, sec, index, ULONG_MAX)
+ free_section(sec);
+
+ mtree_destroy(&mm->sframe_mt);
}
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 4600e7605cab..b32fcf167cc2 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -11,6 +11,7 @@
#include <linux/atomic.h>
#include <linux/user_namespace.h>
#include <linux/iommu.h>
+#include <linux/sframe.h>
#include <asm/mmu.h>
#ifndef INIT_MM_CONTEXT
@@ -46,6 +47,7 @@ struct mm_struct init_mm = {
.user_ns = &init_user_ns,
.cpu_bitmap = CPU_BITS_NONE,
INIT_MM_CONTEXT(init_mm)
+ INIT_MM_SFRAME
};
void setup_initial_init_mm(void *start_code, void *end_code,
--
2.48.1
^ permalink raw reply related
* [PATCH v12 00/13] unwind_deferred: Implement sframe handling
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik
This is the implementation of parsing the .sframe section in an ELF file.
It's a continuation of Josh's and Steve's work that can be found here:
https://lore.kernel.org/all/cover.1737511963.git.jpoimboe@kernel.org/
https://lore.kernel.org/all/20250827201548.448472904@kernel.org/
Currently the only way to get a user space stack trace from a stack
walk (and not just copying large amount of user stack into the kernel
ring buffer) is to use frame pointers. This has a few issues. The biggest
one is that compiling frame pointers into every application and library
has been shown to cause performance overhead.
Another issue is that the format of the frames may not always be consistent
between different compilers and some architectures (s390) has no defined
format to do a reliable stack walk. The only way to perform user space
profiling on these architectures is to copy the user stack into the kernel
buffer.
SFrame [1] is now supported in binutils (x86-64, ARM64, and s390). There is
discussions going on about supporting SFrame in LLVM. SFrame acts more like
ORC, and lives in the ELF executable file as its own section. Like ORC it
has two tables where the first table is sorted by instruction pointers (IP)
and using the current IP and finding it's entry in the first table, it will
take you to the second table which will tell you where the return address
of the current function is located and then you can use that address to
look it up in the first table to find the return address of that function,
and so on. This performs a user space stack walk.
Now because the .sframe section lives in the ELF file it needs to be faulted
into memory when it is used. This means that walking the user space stack
requires being in a faultable context. As profilers like perf request a stack
trace in interrupt or NMI context, it cannot do the walking when it is
requested. Instead it must be deferred until it is safe to fault in user
space. One place this is known to be safe is when the task is about to return
back to user space.
This series makes the deferred unwind user code implement SFrame format V2
with the latest format enhancements (i.e. PC-relative SFrame FDE function
start address, represent return address undefined) and enables it on x86-64.
[1]: https://sourceware.org/binutils/wiki/sframe
This series applies on top of Peter Zijlstras latest unwind user
enhancements and perf deferred callchain support on his tip perf/core
branch which has been merged to the tip master branch (f8fdee44bf2f):
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master
with Namhyung Kim's related latest perf tools deferred callchain support
merged on top (if you want to use "perf record --call-graph fp,defer"
and "perf report/script" for testing):
git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git perf/defer-callchain-v4
The to be stack-traced user space programs (and libraries) need to be
built with the latest SFrame stack trace information format V2, with
the recent PC-relative SFrame FDE function start address encoding and
optionally the support to represent return address undefined, as
generated by binutils 2.45+ with assembler option --gsframe.
Changes since v11 (see patch notes for details):
- Rebase on tip master branch (f8fdee44bf2f) with Namhyung Kim's
perf/defer-callchain-v4 branch merged on top.
- Adjust to Peter's latest undwind user enhancements.
- Simplify logic by using an internal SFrame FDE representation, whose
FDE function start address field is an address instead of a PC-relative
offset (from FDE).
- Rename struct sframe_fre to sframe_fre_internal to align with
struct sframe_fde_internal.
- Remove unused pt_regs from unwind_user_next_common() and its
callers. (Peter)
- Simplify unwind_user_next_sframe(). (Peter)
- Fix a few checkpatch errors and warnings.
- Minor cleanups (e.g. move includes, fix indentation).
Changes since v10:
- Support for SFrame V2 PC-relative FDE function start address.
- Support for SFrame V2 representing RA undefined as indication for
outermost frames.
Patches 1, 4, and 12 have been updated to exclusively support the recent
PC-relative SFrame FDE function start address encoding. With binutils 2.45
the SFrame V2 FDE function start address field value is an offset from the
field (i.e. PC-relative) instead of from the .sframe section start. This
is indicated by the new SFrame header flag SFRAME_F_FDE_FUNC_START_PCREL.
Old SFrame V2 sections get rejected with dynamic debug message
"bad/unsupported sframe header".
Patches 7 and 8 add support to unwind user and unwind user sframe for
a recent change of the SFrame V2 format to represent an undefined
return address as an SFrame FRE without any offsets, which is used as
indication for outermost frames. Note that currently only a development
build of binutils mainline generates SFrame information including this
new indication for outermost frames. SFrame information without the new
indication is still supported. Without these patches unwind user sframe
would identify such new SFrame FREs without any offsets as corrupted and
would therefore remove the .sframe section, causing any any further
stack tracing using sframe to fail.
Regards,
Jens
Jens Remus (2):
unwind_user: Stop when reaching an outermost frame
unwind_user/sframe: Add support for outermost frame indication
Josh Poimboeuf (11):
unwind_user/sframe: Add support for reading .sframe headers
unwind_user/sframe: Store .sframe section data in per-mm maple tree
x86/uaccess: Add unsafe_copy_from_user() implementation
unwind_user/sframe: Add support for reading .sframe contents
unwind_user/sframe: Detect .sframe sections in executables
unwind_user/sframe: Wire up unwind_user to sframe
unwind_user/sframe/x86: Enable sframe unwinding on x86
unwind_user/sframe: Remove .sframe section on detected corruption
unwind_user/sframe: Show file name in debug output
unwind_user/sframe: Add .sframe validation option
unwind_user/sframe: Add prctl() interface for registering .sframe
sections
MAINTAINERS | 1 +
arch/Kconfig | 23 ++
arch/x86/Kconfig | 1 +
arch/x86/include/asm/mmu.h | 2 +-
arch/x86/include/asm/uaccess.h | 39 +-
arch/x86/include/asm/unwind_user.h | 6 +-
fs/binfmt_elf.c | 48 ++-
include/linux/mm_types.h | 3 +
include/linux/sframe.h | 60 +++
include/linux/unwind_user_types.h | 5 +-
include/uapi/linux/elf.h | 1 +
include/uapi/linux/prctl.h | 6 +-
kernel/fork.c | 10 +
kernel/sys.c | 9 +
kernel/unwind/Makefile | 3 +-
kernel/unwind/sframe.c | 627 +++++++++++++++++++++++++++++
kernel/unwind/sframe.h | 72 ++++
kernel/unwind/sframe_debug.h | 68 ++++
kernel/unwind/user.c | 29 ++
mm/init-mm.c | 2 +
20 files changed, 996 insertions(+), 19 deletions(-)
create mode 100644 include/linux/sframe.h
create mode 100644 kernel/unwind/sframe.c
create mode 100644 kernel/unwind/sframe.h
create mode 100644 kernel/unwind/sframe_debug.h
--
2.48.1
^ permalink raw reply
* [PATCH v12 06/13] unwind_user/sframe: Wire up unwind_user to sframe
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
Now that the sframe infrastructure is fully in place, make it work by
hooking it up to the unwind_user interface.
[ Jens Remus: Remove unused pt_regs from unwind_user_next_common() and
its callers. Simplify unwind_user_next_sframe(). ]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Remove unused pt_regs from unwind_user_next_common() and its
callers. (Peter)
- Simplify unwind_user_next_sframe(). (Peter)
arch/Kconfig | 1 +
include/linux/unwind_user_types.h | 4 +++-
kernel/unwind/user.c | 23 +++++++++++++++++++++++
3 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index cdb0e72773be..ab1941ef1411 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -491,6 +491,7 @@ config HAVE_UNWIND_USER_FP
config HAVE_UNWIND_USER_SFRAME
bool
+ select UNWIND_USER
config HAVE_PERF_REGS
bool
diff --git a/include/linux/unwind_user_types.h b/include/linux/unwind_user_types.h
index 412729a269bc..43e4b160883f 100644
--- a/include/linux/unwind_user_types.h
+++ b/include/linux/unwind_user_types.h
@@ -9,7 +9,8 @@
* available.
*/
enum unwind_user_type_bits {
- UNWIND_USER_TYPE_FP_BIT = 0,
+ UNWIND_USER_TYPE_SFRAME_BIT = 0,
+ UNWIND_USER_TYPE_FP_BIT = 1,
NR_UNWIND_USER_TYPE_BITS,
};
@@ -17,6 +18,7 @@ enum unwind_user_type_bits {
enum unwind_user_type {
/* Type "none" for the start of stack walk iteration. */
UNWIND_USER_TYPE_NONE = 0,
+ UNWIND_USER_TYPE_SFRAME = BIT(UNWIND_USER_TYPE_SFRAME_BIT),
UNWIND_USER_TYPE_FP = BIT(UNWIND_USER_TYPE_FP_BIT),
};
diff --git a/kernel/unwind/user.c b/kernel/unwind/user.c
index 39e270789444..7644ab9f6a61 100644
--- a/kernel/unwind/user.c
+++ b/kernel/unwind/user.c
@@ -7,6 +7,7 @@
#include <linux/sched/task_stack.h>
#include <linux/unwind_user.h>
#include <linux/uaccess.h>
+#include <linux/sframe.h>
#define for_each_user_frame(state) \
for (unwind_user_start(state); !(state)->done; unwind_user_next(state))
@@ -86,6 +87,16 @@ static int unwind_user_next_fp(struct unwind_user_state *state)
#endif
}
+static int unwind_user_next_sframe(struct unwind_user_state *state)
+{
+ struct unwind_user_frame frame;
+
+ /* sframe expects the frame to be local storage */
+ if (sframe_find(state->ip, &frame))
+ return -ENOENT;
+ return unwind_user_next_common(state, &frame);
+}
+
static int unwind_user_next(struct unwind_user_state *state)
{
unsigned long iter_mask = state->available_types;
@@ -99,6 +110,16 @@ static int unwind_user_next(struct unwind_user_state *state)
state->current_type = type;
switch (type) {
+ case UNWIND_USER_TYPE_SFRAME:
+ switch (unwind_user_next_sframe(state)) {
+ case 0:
+ return 0;
+ case -ENOENT:
+ continue; /* Try next method. */
+ default:
+ state->done = true;
+ }
+ break;
case UNWIND_USER_TYPE_FP:
if (!unwind_user_next_fp(state))
return 0;
@@ -127,6 +148,8 @@ static int unwind_user_start(struct unwind_user_state *state)
return -EINVAL;
}
+ if (current_has_sframe())
+ state->available_types |= UNWIND_USER_TYPE_SFRAME;
if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP))
state->available_types |= UNWIND_USER_TYPE_FP;
--
2.48.1
^ permalink raw reply related
* [PATCH v12 08/13] unwind_user/sframe: Add support for outermost frame indication
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
SFrame may represent an undefined return address (RA) as SFrame FRE
without any offsets as indication for an outermost frame.
Cc: Steven Rostedt <rostedt@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v11:
- New patch.
kernel/unwind/sframe.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index d4ef825b1cbc..1e877c3e5417 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -33,6 +33,7 @@ struct sframe_fre_internal {
s32 ra_off;
s32 fp_off;
u8 info;
+ bool ra_undefined;
};
DEFINE_STATIC_SRCU(sframe_srcu);
@@ -187,6 +188,7 @@ static __always_inline int __read_fre(struct sframe_section *sec,
unsigned char offset_count, offset_size;
s32 cfa_off, ra_off, fp_off;
unsigned long cur = fre_addr;
+ bool ra_undefined = false;
unsigned char addr_size;
u32 ip_off;
u8 info;
@@ -205,7 +207,7 @@ static __always_inline int __read_fre(struct sframe_section *sec,
UNSAFE_GET_USER_INC(info, cur, 1, Efault);
offset_count = SFRAME_FRE_OFFSET_COUNT(info);
offset_size = offset_size_enum_to_size(SFRAME_FRE_OFFSET_SIZE(info));
- if (!offset_count || !offset_size)
+ if (!offset_size)
return -EFAULT;
if (cur + (offset_count * offset_size) > sec->fres_end)
@@ -213,6 +215,14 @@ static __always_inline int __read_fre(struct sframe_section *sec,
fre->size = addr_size + 1 + (offset_count * offset_size);
+ if (!offset_count) {
+ cfa_off = 0;
+ ra_off = 0;
+ fp_off = 0;
+ ra_undefined = true;
+ goto done;
+ }
+
UNSAFE_GET_USER_INC(cfa_off, cur, offset_size, Efault);
offset_count--;
@@ -233,11 +243,13 @@ static __always_inline int __read_fre(struct sframe_section *sec,
if (offset_count)
return -EFAULT;
+done:
fre->ip_off = ip_off;
fre->cfa_off = cfa_off;
fre->ra_off = ra_off;
fre->fp_off = fp_off;
fre->info = info;
+ fre->ra_undefined = ra_undefined;
return 0;
@@ -298,6 +310,7 @@ static __always_inline int __find_fre(struct sframe_section *sec,
frame->ra_off = fre->ra_off;
frame->fp_off = fre->fp_off;
frame->use_fp = SFRAME_FRE_CFA_BASE_REG_ID(fre->info) == SFRAME_BASE_REG_FP;
+ frame->outermost = fre->ra_undefined;
return 0;
}
--
2.48.1
^ permalink raw reply related
* [PATCH v12 11/13] unwind_user/sframe: Show file name in debug output
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
When debugging sframe issues, the error messages aren't all that helpful
without knowing what file a corresponding .sframe section belongs to.
Prefix debug output strings with the file name.
[ Jens Remus: Fix checkpatch error "space prohibited before that close
parenthesis ')'". ]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Fix checkpatch error "space prohibited before that close
parenthesis ')'".
include/linux/sframe.h | 4 +++-
kernel/unwind/sframe.c | 23 ++++++++++--------
kernel/unwind/sframe_debug.h | 45 +++++++++++++++++++++++++++++++-----
3 files changed, 56 insertions(+), 16 deletions(-)
diff --git a/include/linux/sframe.h b/include/linux/sframe.h
index 9a72209696f9..b79c5ec09229 100644
--- a/include/linux/sframe.h
+++ b/include/linux/sframe.h
@@ -10,7 +10,9 @@
struct sframe_section {
struct rcu_head rcu;
-
+#ifdef CONFIG_DYNAMIC_DEBUG
+ const char *filename;
+#endif
unsigned long sframe_start;
unsigned long sframe_end;
unsigned long text_start;
diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index 61340ee524c2..7d3e286c1b23 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -343,14 +343,17 @@ int sframe_find(unsigned long ip, struct unwind_user_frame *frame)
end:
user_read_access_end();
- if (ret == -EFAULT)
+ if (ret == -EFAULT) {
+ dbg_sec("removing bad .sframe section\n");
WARN_ON_ONCE(sframe_remove_section(sec->sframe_start));
+ }
return ret;
}
static void free_section(struct sframe_section *sec)
{
+ dbg_free(sec);
kfree(sec);
}
@@ -361,7 +364,7 @@ static int sframe_read_header(struct sframe_section *sec)
unsigned int num_fdes;
if (copy_from_user(&shdr, (void __user *)sec->sframe_start, sizeof(shdr))) {
- dbg("header usercopy failed\n");
+ dbg_sec("header usercopy failed\n");
return -EFAULT;
}
@@ -370,18 +373,18 @@ static int sframe_read_header(struct sframe_section *sec)
!(shdr.preamble.flags & SFRAME_F_FDE_SORTED) ||
!(shdr.preamble.flags & SFRAME_F_FDE_FUNC_START_PCREL) ||
shdr.auxhdr_len) {
- dbg("bad/unsupported sframe header\n");
+ dbg_sec("bad/unsupported sframe header\n");
return -EINVAL;
}
if (!shdr.num_fdes || !shdr.num_fres) {
- dbg("no fde/fre entries\n");
+ dbg_sec("no fde/fre entries\n");
return -EINVAL;
}
header_end = sec->sframe_start + SFRAME_HEADER_SIZE(shdr);
if (header_end >= sec->sframe_end) {
- dbg("header doesn't fit in section\n");
+ dbg_sec("header doesn't fit in section\n");
return -EINVAL;
}
@@ -393,7 +396,7 @@ static int sframe_read_header(struct sframe_section *sec)
fres_end = fres_start + shdr.fre_len;
if (fres_start < fdes_end || fres_end > sec->sframe_end) {
- dbg("inconsistent fde/fre offsets\n");
+ dbg_sec("inconsistent fde/fre offsets\n");
return -EINVAL;
}
@@ -449,6 +452,8 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
sec->text_start = text_start;
sec->text_end = text_end;
+ dbg_init(sec);
+
ret = sframe_read_header(sec);
if (ret) {
dbg_print_header(sec);
@@ -457,8 +462,8 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
ret = mtree_insert_range(sframe_mt, sec->text_start, sec->text_end, sec, GFP_KERNEL);
if (ret) {
- dbg("mtree_insert_range failed: text=%lx-%lx\n",
- sec->text_start, sec->text_end);
+ dbg_sec("mtree_insert_range failed: text=%lx-%lx\n",
+ sec->text_start, sec->text_end);
goto err_free;
}
@@ -480,7 +485,7 @@ static int __sframe_remove_section(struct mm_struct *mm,
struct sframe_section *sec)
{
if (!mtree_erase(&mm->sframe_mt, sec->text_start)) {
- dbg("mtree_erase failed: text=%lx\n", sec->text_start);
+ dbg_sec("mtree_erase failed: text=%lx\n", sec->text_start);
return -EINVAL;
}
diff --git a/kernel/unwind/sframe_debug.h b/kernel/unwind/sframe_debug.h
index 055c8c8fae24..cd3e95e3961f 100644
--- a/kernel/unwind/sframe_debug.h
+++ b/kernel/unwind/sframe_debug.h
@@ -10,26 +10,59 @@
#define dbg(fmt, ...) \
pr_debug("%s (%d): " fmt, current->comm, current->pid, ##__VA_ARGS__)
+#define dbg_sec(fmt, ...) \
+ dbg("%s: " fmt, sec->filename, ##__VA_ARGS__)
+
static __always_inline void dbg_print_header(struct sframe_section *sec)
{
unsigned long fdes_end;
fdes_end = sec->fdes_start + (sec->num_fdes * sizeof(struct sframe_fde));
- dbg("SEC: sframe:0x%lx-0x%lx text:0x%lx-0x%lx "
- "fdes:0x%lx-0x%lx fres:0x%lx-0x%lx "
- "ra_off:%d fp_off:%d\n",
- sec->sframe_start, sec->sframe_end, sec->text_start, sec->text_end,
- sec->fdes_start, fdes_end, sec->fres_start, sec->fres_end,
- sec->ra_off, sec->fp_off);
+ dbg_sec("SEC: sframe:0x%lx-0x%lx text:0x%lx-0x%lx "
+ "fdes:0x%lx-0x%lx fres:0x%lx-0x%lx "
+ "ra_off:%d fp_off:%d\n",
+ sec->sframe_start, sec->sframe_end, sec->text_start, sec->text_end,
+ sec->fdes_start, fdes_end, sec->fres_start, sec->fres_end,
+ sec->ra_off, sec->fp_off);
+}
+
+static inline void dbg_init(struct sframe_section *sec)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ guard(mmap_read_lock)(mm);
+ vma = vma_lookup(mm, sec->sframe_start);
+ if (!vma)
+ sec->filename = kstrdup("(vma gone???)", GFP_KERNEL);
+ else if (vma->vm_file)
+ sec->filename = kstrdup_quotable_file(vma->vm_file, GFP_KERNEL);
+ else if (vma->vm_ops && vma->vm_ops->name)
+ sec->filename = kstrdup(vma->vm_ops->name(vma), GFP_KERNEL);
+ else if (arch_vma_name(vma))
+ sec->filename = kstrdup(arch_vma_name(vma), GFP_KERNEL);
+ else if (!vma->vm_mm)
+ sec->filename = kstrdup("(vdso)", GFP_KERNEL);
+ else
+ sec->filename = kstrdup("(anonymous)", GFP_KERNEL);
+}
+
+static inline void dbg_free(struct sframe_section *sec)
+{
+ kfree(sec->filename);
}
#else /* !CONFIG_DYNAMIC_DEBUG */
#define dbg(args...) no_printk(args)
+#define dbg_sec(args...) no_printk(args)
static inline void dbg_print_header(struct sframe_section *sec) {}
+static inline void dbg_init(struct sframe_section *sec) {}
+static inline void dbg_free(struct sframe_section *sec) {}
+
#endif /* !CONFIG_DYNAMIC_DEBUG */
#endif /* _SFRAME_DEBUG_H */
--
2.48.1
^ permalink raw reply related
* [PATCH v12 01/13] unwind_user/sframe: Add support for reading .sframe headers
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
In preparation for unwinding user space stacks with sframe, add basic
sframe compile infrastructure and support for reading the .sframe
section header.
sframe_add_section() reads the header and unconditionally returns an
error, so it's not very useful yet. A subsequent patch will improve
that.
Link: https://lore.kernel.org/all/f27e8463783febfa0dabb0432a3dd6be8ad98412.1737511963.git.jpoimboe@kernel.org/
[ Jens Remus: Add support for PC-relative FDE function start address.
Cleanup includes and indentation. ]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Move include of linux/unwind_user_types.h to "unwind_user/sframe: Add
support for reading .sframe contents".
- Move include of linux/mm_types.h and variable sframe_mt to
"unwind_user/sframe: Store sframe section data in per-mm maple tree".
- Fix indentation of struct sframe_fde field padding.
Changes in v11:
- Support for SFrame V2 PC-relative FDE function start address.
MAINTAINERS | 1 +
arch/Kconfig | 3 +
include/linux/sframe.h | 37 +++++++++++
kernel/unwind/Makefile | 3 +-
kernel/unwind/sframe.c | 136 +++++++++++++++++++++++++++++++++++++++++
kernel/unwind/sframe.h | 72 ++++++++++++++++++++++
6 files changed, 251 insertions(+), 1 deletion(-)
create mode 100644 include/linux/sframe.h
create mode 100644 kernel/unwind/sframe.c
create mode 100644 kernel/unwind/sframe.h
diff --git a/MAINTAINERS b/MAINTAINERS
index b0569f6fc48f..eb65bf7bd10d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -26811,6 +26811,7 @@ USERSPACE STACK UNWINDING
M: Josh Poimboeuf <jpoimboe@kernel.org>
M: Steven Rostedt <rostedt@goodmis.org>
S: Maintained
+F: include/linux/sframe.h
F: include/linux/unwind*.h
F: kernel/unwind/
diff --git a/arch/Kconfig b/arch/Kconfig
index 61130b88964b..cdb0e72773be 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -489,6 +489,9 @@ config HAVE_UNWIND_USER_FP
bool
select UNWIND_USER
+config HAVE_UNWIND_USER_SFRAME
+ bool
+
config HAVE_PERF_REGS
bool
help
diff --git a/include/linux/sframe.h b/include/linux/sframe.h
new file mode 100644
index 000000000000..0642595534f9
--- /dev/null
+++ b/include/linux/sframe.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SFRAME_H
+#define _LINUX_SFRAME_H
+
+#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME
+
+struct sframe_section {
+ unsigned long sframe_start;
+ unsigned long sframe_end;
+ unsigned long text_start;
+ unsigned long text_end;
+
+ unsigned long fdes_start;
+ unsigned long fres_start;
+ unsigned long fres_end;
+ unsigned int num_fdes;
+
+ signed char ra_off;
+ signed char fp_off;
+};
+
+extern int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
+ unsigned long text_start, unsigned long text_end);
+extern int sframe_remove_section(unsigned long sframe_addr);
+
+#else /* !CONFIG_HAVE_UNWIND_USER_SFRAME */
+
+static inline int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
+ unsigned long text_start, unsigned long text_end)
+{
+ return -ENOSYS;
+}
+static inline int sframe_remove_section(unsigned long sframe_addr) { return -ENOSYS; }
+
+#endif /* CONFIG_HAVE_UNWIND_USER_SFRAME */
+
+#endif /* _LINUX_SFRAME_H */
diff --git a/kernel/unwind/Makefile b/kernel/unwind/Makefile
index eae37bea54fd..146038165865 100644
--- a/kernel/unwind/Makefile
+++ b/kernel/unwind/Makefile
@@ -1 +1,2 @@
- obj-$(CONFIG_UNWIND_USER) += user.o deferred.o
+ obj-$(CONFIG_UNWIND_USER) += user.o deferred.o
+ obj-$(CONFIG_HAVE_UNWIND_USER_SFRAME) += sframe.o
diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
new file mode 100644
index 000000000000..26bb16f76a8d
--- /dev/null
+++ b/kernel/unwind/sframe.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Userspace sframe access functions
+ */
+
+#define pr_fmt(fmt) "sframe: " fmt
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/srcu.h>
+#include <linux/uaccess.h>
+#include <linux/mm.h>
+#include <linux/string_helpers.h>
+#include <linux/sframe.h>
+#include <linux/unwind_user_types.h>
+
+#include "sframe.h"
+
+#define dbg(fmt, ...) \
+ pr_debug("%s (%d): " fmt, current->comm, current->pid, ##__VA_ARGS__)
+
+static void free_section(struct sframe_section *sec)
+{
+ kfree(sec);
+}
+
+static int sframe_read_header(struct sframe_section *sec)
+{
+ unsigned long header_end, fdes_start, fdes_end, fres_start, fres_end;
+ struct sframe_header shdr;
+ unsigned int num_fdes;
+
+ if (copy_from_user(&shdr, (void __user *)sec->sframe_start, sizeof(shdr))) {
+ dbg("header usercopy failed\n");
+ return -EFAULT;
+ }
+
+ if (shdr.preamble.magic != SFRAME_MAGIC ||
+ shdr.preamble.version != SFRAME_VERSION_2 ||
+ !(shdr.preamble.flags & SFRAME_F_FDE_SORTED) ||
+ !(shdr.preamble.flags & SFRAME_F_FDE_FUNC_START_PCREL) ||
+ shdr.auxhdr_len) {
+ dbg("bad/unsupported sframe header\n");
+ return -EINVAL;
+ }
+
+ if (!shdr.num_fdes || !shdr.num_fres) {
+ dbg("no fde/fre entries\n");
+ return -EINVAL;
+ }
+
+ header_end = sec->sframe_start + SFRAME_HEADER_SIZE(shdr);
+ if (header_end >= sec->sframe_end) {
+ dbg("header doesn't fit in section\n");
+ return -EINVAL;
+ }
+
+ num_fdes = shdr.num_fdes;
+ fdes_start = header_end + shdr.fdes_off;
+ fdes_end = fdes_start + (num_fdes * sizeof(struct sframe_fde));
+
+ fres_start = header_end + shdr.fres_off;
+ fres_end = fres_start + shdr.fre_len;
+
+ if (fres_start < fdes_end || fres_end > sec->sframe_end) {
+ dbg("inconsistent fde/fre offsets\n");
+ return -EINVAL;
+ }
+
+ sec->num_fdes = num_fdes;
+ sec->fdes_start = fdes_start;
+ sec->fres_start = fres_start;
+ sec->fres_end = fres_end;
+
+ sec->ra_off = shdr.cfa_fixed_ra_offset;
+ sec->fp_off = shdr.cfa_fixed_fp_offset;
+
+ return 0;
+}
+
+int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
+ unsigned long text_start, unsigned long text_end)
+{
+ struct vm_area_struct *sframe_vma, *text_vma;
+ struct mm_struct *mm = current->mm;
+ struct sframe_section *sec;
+ int ret;
+
+ if (!sframe_start || !sframe_end || !text_start || !text_end) {
+ dbg("zero-length sframe/text address\n");
+ return -EINVAL;
+ }
+
+ scoped_guard(mmap_read_lock, mm) {
+ sframe_vma = vma_lookup(mm, sframe_start);
+ if (!sframe_vma || sframe_end > sframe_vma->vm_end) {
+ dbg("bad sframe address (0x%lx - 0x%lx)\n",
+ sframe_start, sframe_end);
+ return -EINVAL;
+ }
+
+ text_vma = vma_lookup(mm, text_start);
+ if (!text_vma ||
+ !(text_vma->vm_flags & VM_EXEC) ||
+ text_end > text_vma->vm_end) {
+ dbg("bad text address (0x%lx - 0x%lx)\n",
+ text_start, text_end);
+ return -EINVAL;
+ }
+ }
+
+ sec = kzalloc(sizeof(*sec), GFP_KERNEL);
+ if (!sec)
+ return -ENOMEM;
+
+ sec->sframe_start = sframe_start;
+ sec->sframe_end = sframe_end;
+ sec->text_start = text_start;
+ sec->text_end = text_end;
+
+ ret = sframe_read_header(sec);
+ if (ret)
+ goto err_free;
+
+ /* TODO nowhere to store it yet - just free it and return an error */
+ ret = -ENOSYS;
+
+err_free:
+ free_section(sec);
+ return ret;
+}
+
+int sframe_remove_section(unsigned long sframe_start)
+{
+ return -ENOSYS;
+}
diff --git a/kernel/unwind/sframe.h b/kernel/unwind/sframe.h
new file mode 100644
index 000000000000..69ce0d5b9694
--- /dev/null
+++ b/kernel/unwind/sframe.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * From https://www.sourceware.org/binutils/docs/sframe-spec.html
+ */
+#ifndef _SFRAME_H
+#define _SFRAME_H
+
+#include <linux/types.h>
+
+#define SFRAME_VERSION_1 1
+#define SFRAME_VERSION_2 2
+#define SFRAME_MAGIC 0xdee2
+
+#define SFRAME_F_FDE_SORTED 0x1
+#define SFRAME_F_FRAME_POINTER 0x2
+#define SFRAME_F_FDE_FUNC_START_PCREL 0x4
+
+#define SFRAME_ABI_AARCH64_ENDIAN_BIG 1
+#define SFRAME_ABI_AARCH64_ENDIAN_LITTLE 2
+#define SFRAME_ABI_AMD64_ENDIAN_LITTLE 3
+
+#define SFRAME_FDE_TYPE_PCINC 0
+#define SFRAME_FDE_TYPE_PCMASK 1
+
+struct sframe_preamble {
+ u16 magic;
+ u8 version;
+ u8 flags;
+} __packed;
+
+struct sframe_header {
+ struct sframe_preamble preamble;
+ u8 abi_arch;
+ s8 cfa_fixed_fp_offset;
+ s8 cfa_fixed_ra_offset;
+ u8 auxhdr_len;
+ u32 num_fdes;
+ u32 num_fres;
+ u32 fre_len;
+ u32 fdes_off;
+ u32 fres_off;
+} __packed;
+
+#define SFRAME_HEADER_SIZE(header) \
+ ((sizeof(struct sframe_header) + header.auxhdr_len))
+
+#define SFRAME_AARCH64_PAUTH_KEY_A 0
+#define SFRAME_AARCH64_PAUTH_KEY_B 1
+
+struct sframe_fde {
+ s32 start_addr;
+ u32 func_size;
+ u32 fres_off;
+ u32 fres_num;
+ u8 info;
+ u8 rep_size;
+ u16 padding;
+} __packed;
+
+#define SFRAME_FUNC_FRE_TYPE(data) (data & 0xf)
+#define SFRAME_FUNC_FDE_TYPE(data) ((data >> 4) & 0x1)
+#define SFRAME_FUNC_PAUTH_KEY(data) ((data >> 5) & 0x1)
+
+#define SFRAME_BASE_REG_FP 0
+#define SFRAME_BASE_REG_SP 1
+
+#define SFRAME_FRE_CFA_BASE_REG_ID(data) (data & 0x1)
+#define SFRAME_FRE_OFFSET_COUNT(data) ((data >> 1) & 0xf)
+#define SFRAME_FRE_OFFSET_SIZE(data) ((data >> 5) & 0x3)
+#define SFRAME_FRE_MANGLED_RA_P(data) ((data >> 7) & 0x1)
+
+#endif /* _SFRAME_H */
--
2.48.1
^ permalink raw reply related
* [PATCH v12 03/13] x86/uaccess: Add unsafe_copy_from_user() implementation
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
Add an x86 implementation of unsafe_copy_from_user() similar to the
existing unsafe_copy_to_user().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
arch/x86/include/asm/uaccess.h | 39 +++++++++++++++++++++++++---------
1 file changed, 29 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 367297b188c3..dfe143235967 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -598,7 +598,7 @@ _label: \
* We want the unsafe accessors to always be inlined and use
* the error labels - thus the macro games.
*/
-#define unsafe_copy_loop(dst, src, len, type, label) \
+#define unsafe_copy_to_user_loop(dst, src, len, type, label) \
while (len >= sizeof(type)) { \
unsafe_put_user(*(type *)(src),(type __user *)(dst),label); \
dst += sizeof(type); \
@@ -606,15 +606,34 @@ _label: \
len -= sizeof(type); \
}
-#define unsafe_copy_to_user(_dst,_src,_len,label) \
-do { \
- char __user *__ucu_dst = (_dst); \
- const char *__ucu_src = (_src); \
- size_t __ucu_len = (_len); \
- unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label); \
- unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label); \
- unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label); \
- unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label); \
+#define unsafe_copy_to_user(_dst, _src, _len, label) \
+do { \
+ void __user *__dst = (_dst); \
+ const void *__src = (_src); \
+ size_t __len = (_len); \
+ unsafe_copy_to_user_loop(__dst, __src, __len, u64, label); \
+ unsafe_copy_to_user_loop(__dst, __src, __len, u32, label); \
+ unsafe_copy_to_user_loop(__dst, __src, __len, u16, label); \
+ unsafe_copy_to_user_loop(__dst, __src, __len, u8, label); \
+} while (0)
+
+#define unsafe_copy_from_user_loop(dst, src, len, type, label) \
+ while (len >= sizeof(type)) { \
+ unsafe_get_user(*(type *)(dst), (type __user *)(src), label); \
+ dst += sizeof(type); \
+ src += sizeof(type); \
+ len -= sizeof(type); \
+ }
+
+#define unsafe_copy_from_user(_dst, _src, _len, label) \
+do { \
+ void *__dst = (_dst); \
+ void __user *__src = (_src); \
+ size_t __len = (_len); \
+ unsafe_copy_from_user_loop(__dst, __src, __len, u64, label); \
+ unsafe_copy_from_user_loop(__dst, __src, __len, u32, label); \
+ unsafe_copy_from_user_loop(__dst, __src, __len, u16, label); \
+ unsafe_copy_from_user_loop(__dst, __src, __len, u8, label); \
} while (0)
#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
--
2.48.1
^ permalink raw reply related
* [PATCH v12 12/13] unwind_user/sframe: Add .sframe validation option
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
Add a debug feature to validate all .sframe sections when first loading
the file rather than on demand.
[ Jens Remus: Add support for PC-relative FDE function start address.
Adjust to rename of struct sframe_fre to sframe_fre_internal. ]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Adjust to use internal SFrame FDE representation.
- Adjust to rename of struct sframe_fre to sframe_fre_internal.
Changes in v11:
- Support for SFrame V2 PC-relative FDE function start address.
arch/Kconfig | 19 +++++++++
kernel/unwind/sframe.c | 97 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 116 insertions(+)
diff --git a/arch/Kconfig b/arch/Kconfig
index ab1941ef1411..06c4f909398c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -493,6 +493,25 @@ config HAVE_UNWIND_USER_SFRAME
bool
select UNWIND_USER
+config SFRAME_VALIDATION
+ bool "Enable .sframe section debugging"
+ depends on HAVE_UNWIND_USER_SFRAME
+ depends on DYNAMIC_DEBUG
+ help
+ When adding an .sframe section for a task, validate the entire
+ section immediately rather than on demand.
+
+ This is a debug feature which is helpful for rooting out .sframe
+ section issues. If the .sframe section is corrupt, it will fail to
+ load immediately, with more information provided in dynamic printks.
+
+ This has a significant page cache footprint due to its reading of the
+ entire .sframe section for every loaded executable and shared
+ library. Also, it's done for all processes, even those which don't
+ get stack traced by the kernel. Not recommended for general use.
+
+ If unsure, say N.
+
config HAVE_PERF_REGS
bool
help
diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index 7d3e286c1b23..6465e7a315bc 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -351,6 +351,99 @@ int sframe_find(unsigned long ip, struct unwind_user_frame *frame)
return ret;
}
+#ifdef CONFIG_SFRAME_VALIDATION
+
+static int safe_read_fde(struct sframe_section *sec,
+ unsigned int fde_num, struct sframe_fde_internal *fde)
+{
+ int ret;
+
+ if (!user_read_access_begin((void __user *)sec->sframe_start,
+ sec->sframe_end - sec->sframe_start))
+ return -EFAULT;
+ ret = __read_fde(sec, fde_num, fde);
+ user_read_access_end();
+ return ret;
+}
+
+static int safe_read_fre(struct sframe_section *sec,
+ struct sframe_fde_internal *fde,
+ unsigned long fre_addr,
+ struct sframe_fre_internal *fre)
+{
+ int ret;
+
+ if (!user_read_access_begin((void __user *)sec->sframe_start,
+ sec->sframe_end - sec->sframe_start))
+ return -EFAULT;
+ ret = __read_fre(sec, fde, fre_addr, fre);
+ user_read_access_end();
+ return ret;
+}
+
+static int sframe_validate_section(struct sframe_section *sec)
+{
+ unsigned long prev_ip = 0;
+ unsigned int i;
+
+ for (i = 0; i < sec->num_fdes; i++) {
+ struct sframe_fre_internal *fre, *prev_fre = NULL;
+ unsigned long ip, fre_addr;
+ struct sframe_fde_internal fde;
+ struct sframe_fre_internal fres[2];
+ bool which = false;
+ unsigned int j;
+ int ret;
+
+ ret = safe_read_fde(sec, i, &fde);
+ if (ret)
+ return ret;
+
+ ip = fde.func_start_addr;
+ if (ip <= prev_ip) {
+ dbg_sec("fde %u not sorted\n", i);
+ return -EFAULT;
+ }
+ prev_ip = ip;
+
+ fre_addr = sec->fres_start + fde.fres_off;
+ for (j = 0; j < fde.fres_num; j++) {
+ int ret;
+
+ fre = which ? fres : fres + 1;
+ which = !which;
+
+ ret = safe_read_fre(sec, &fde, fre_addr, fre);
+ if (ret) {
+ dbg_sec("fde %u: __read_fre(%u) failed\n", i, j);
+ dbg_sec("FDE: func_start_addr:0x%lx func_size:0x%x fres_off:0x%x fres_num:%d info:%u rep_size:%u\n",
+ fde.func_start_addr, fde.func_size,
+ fde.fres_off, fde.fres_num,
+ fde.info, fde.rep_size);
+ return ret;
+ }
+
+ fre_addr += fre->size;
+
+ if (prev_fre && fre->ip_off <= prev_fre->ip_off) {
+ dbg_sec("fde %u: fre %u not sorted\n", i, j);
+ return -EFAULT;
+ }
+
+ prev_fre = fre;
+ }
+ }
+
+ return 0;
+}
+
+#else /* !CONFIG_SFRAME_VALIDATION */
+
+static int sframe_validate_section(struct sframe_section *sec) { return 0; }
+
+#endif /* !CONFIG_SFRAME_VALIDATION */
+
+
static void free_section(struct sframe_section *sec)
{
dbg_free(sec);
@@ -460,6 +553,10 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
goto err_free;
}
+ ret = sframe_validate_section(sec);
+ if (ret)
+ goto err_free;
+
ret = mtree_insert_range(sframe_mt, sec->text_start, sec->text_end, sec, GFP_KERNEL);
if (ret) {
dbg_sec("mtree_insert_range failed: text=%lx-%lx\n",
--
2.48.1
^ permalink raw reply related
* [PATCH v12 04/13] unwind_user/sframe: Add support for reading .sframe contents
From: Jens Remus @ 2025-11-19 13:23 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, bpf, x86, linux-mm,
Steven Rostedt
Cc: Jens Remus, Josh Poimboeuf, Masami Hiramatsu, Mathieu Desnoyers,
Peter Zijlstra, Ingo Molnar, Jiri Olsa, Arnaldo Carvalho de Melo,
Namhyung Kim, Thomas Gleixner, Andrii Nakryiko, Indu Bhagat,
Jose E. Marchesi, Beau Belgrave, Linus Torvalds, Andrew Morton,
Florian Weimer, Kees Cook, Carlos O'Donell, Sam James,
Dylan Hatch, Borislav Petkov, Dave Hansen, David Hildenbrand,
H. Peter Anvin, Liam R. Howlett, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka,
Heiko Carstens, Vasily Gorbik, Steven Rostedt (Google)
In-Reply-To: <20251119132323.1281768-1-jremus@linux.ibm.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
In preparation for using sframe to unwind user space stacks, add an
sframe_find() interface for finding the sframe information associated
with a given text address.
For performance, use user_read_access_begin() and the corresponding
unsafe_*() accessors. Note that use of pr_debug() in uaccess-enabled
regions would break noinstr validation, so there aren't any debug
messages yet. That will be added in a subsequent commit.
Link: https://lore.kernel.org/all/77c0d1ec143bf2a53d66c4ecb190e7e0a576fbfd.1737511963.git.jpoimboe@kernel.org/
Link: https://lore.kernel.org/all/b35ca3a3-8de5-4d32-8d30-d4e562f6b0de@linux.ibm.com/
[ Jens Remus: Add support for PC-relative FDE function start address.
Simplify logic by using an internal SFrame FDE representation, whose
FDE function start address field is an address instead of a PC-relative
offset (from FDE). Rename struct sframe_fre to sframe_fre_internal to
align with struct sframe_fde_internal. Cleanup includes. Fix
checkpatch errors "spaces required around that ':'". ]
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Indu Bhagat <indu.bhagat@oracle.com>
Cc: "Jose E. Marchesi" <jemarch@gnu.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Jens Remus <jremus@linux.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Sam James <sam@gentoo.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Carlos O'Donell" <codonell@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
Notes (jremus):
Changes in v12:
- Simplify logic by using an internal SFrame FDE representation,
whose FDE function start address field is an address instead of
a PC-relative offset (from FDE).
- Rename struct sframe_fre to sframe_fre_internal to align with
struct sframe_fde_internal.
- Add include of linux/unwind_user_types.h from "unwind_user/sframe:
Add support for reading .sframe headers".
- Fix checkpatch errors "spaces required around that ':'".
Changes in v11:
- Support for SFrame V2 PC-relative FDE function start address.
include/linux/sframe.h | 6 +
kernel/unwind/sframe.c | 330 ++++++++++++++++++++++++++++++++++-
kernel/unwind/sframe_debug.h | 35 ++++
3 files changed, 367 insertions(+), 4 deletions(-)
create mode 100644 kernel/unwind/sframe_debug.h
diff --git a/include/linux/sframe.h b/include/linux/sframe.h
index 7ea6a97ed8af..9a72209696f9 100644
--- a/include/linux/sframe.h
+++ b/include/linux/sframe.h
@@ -3,10 +3,14 @@
#define _LINUX_SFRAME_H
#include <linux/mm_types.h>
+#include <linux/srcu.h>
+#include <linux/unwind_user_types.h>
#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME
struct sframe_section {
+ struct rcu_head rcu;
+
unsigned long sframe_start;
unsigned long sframe_end;
unsigned long text_start;
@@ -27,6 +31,7 @@ extern void sframe_free_mm(struct mm_struct *mm);
extern int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
unsigned long text_start, unsigned long text_end);
extern int sframe_remove_section(unsigned long sframe_addr);
+extern int sframe_find(unsigned long ip, struct unwind_user_frame *frame);
static inline bool current_has_sframe(void)
{
@@ -45,6 +50,7 @@ static inline int sframe_add_section(unsigned long sframe_start, unsigned long s
return -ENOSYS;
}
static inline int sframe_remove_section(unsigned long sframe_addr) { return -ENOSYS; }
+static inline int sframe_find(unsigned long ip, struct unwind_user_frame *frame) { return -ENOSYS; }
static inline bool current_has_sframe(void) { return false; }
#endif /* CONFIG_HAVE_UNWIND_USER_SFRAME */
diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index 149ce70e4229..d4ef825b1cbc 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -15,9 +15,322 @@
#include <linux/unwind_user_types.h>
#include "sframe.h"
+#include "sframe_debug.h"
+
+struct sframe_fde_internal {
+ unsigned long func_start_addr;
+ u32 func_size;
+ u32 fres_off;
+ u32 fres_num;
+ u8 info;
+ u8 rep_size;
+};
+
+struct sframe_fre_internal {
+ unsigned int size;
+ u32 ip_off;
+ s32 cfa_off;
+ s32 ra_off;
+ s32 fp_off;
+ u8 info;
+};
+
+DEFINE_STATIC_SRCU(sframe_srcu);
+
+static __always_inline unsigned char fre_type_to_size(unsigned char fre_type)
+{
+ if (fre_type > 2)
+ return 0;
+ return 1 << fre_type;
+}
+
+static __always_inline unsigned char offset_size_enum_to_size(unsigned char off_size)
+{
+ if (off_size > 2)
+ return 0;
+ return 1 << off_size;
+}
+
+static __always_inline int __read_fde(struct sframe_section *sec,
+ unsigned int fde_num,
+ struct sframe_fde_internal *fde)
+{
+ unsigned long fde_addr, func_addr;
+ struct sframe_fde _fde;
+
+ fde_addr = sec->fdes_start + (fde_num * sizeof(struct sframe_fde));
+ unsafe_copy_from_user(&_fde, (void __user *)fde_addr,
+ sizeof(struct sframe_fde), Efault);
+
+ func_addr = fde_addr + _fde.start_addr;
+ if (func_addr < sec->text_start || func_addr > sec->text_end)
+ return -EINVAL;
+
+ fde->func_start_addr = func_addr;
+ fde->func_size = _fde.func_size;
+ fde->fres_off = _fde.fres_off;
+ fde->fres_num = _fde.fres_num;
+ fde->info = _fde.info;
+ fde->rep_size = _fde.rep_size;
+
+ return 0;
+
+Efault:
+ return -EFAULT;
+}
+
+static __always_inline int __find_fde(struct sframe_section *sec,
+ unsigned long ip,
+ struct sframe_fde_internal *fde)
+{
+ unsigned long func_addr_low = 0, func_addr_high = ULONG_MAX;
+ struct sframe_fde __user *first, *low, *high, *found = NULL;
+ int ret;
+
+ first = (void __user *)sec->fdes_start;
+ low = first;
+ high = first + sec->num_fdes - 1;
+
+ while (low <= high) {
+ struct sframe_fde __user *mid;
+ s32 func_off;
+ unsigned long func_addr;
+
+ mid = low + ((high - low) / 2);
+
+ unsafe_get_user(func_off, (s32 __user *)mid, Efault);
+ func_addr = (unsigned long)mid + func_off;
+
+ if (ip >= func_addr) {
+ if (func_addr < func_addr_low)
+ return -EFAULT;
+
+ func_addr_low = func_addr;
+
+ found = mid;
+ low = mid + 1;
+ } else {
+ if (func_addr > func_addr_high)
+ return -EFAULT;
+
+ func_addr_high = func_addr;
+
+ high = mid - 1;
+ }
+ }
+
+ if (!found)
+ return -EINVAL;
+
+ ret = __read_fde(sec, found - first, fde);
+ if (ret)
+ return ret;
+
+ /* make sure it's not in a gap */
+ if (ip < fde->func_start_addr ||
+ ip >= fde->func_start_addr + fde->func_size)
+ return -EINVAL;
+
+ return 0;
+
+Efault:
+ return -EFAULT;
+}
+
+#define ____UNSAFE_GET_USER_INC(to, from, type, label) \
+({ \
+ type __to; \
+ unsafe_get_user(__to, (type __user *)from, label); \
+ from += sizeof(__to); \
+ to = __to; \
+})
+
+#define __UNSAFE_GET_USER_INC(to, from, size, label, u_or_s) \
+({ \
+ switch (size) { \
+ case 1: \
+ ____UNSAFE_GET_USER_INC(to, from, u_or_s##8, label); \
+ break; \
+ case 2: \
+ ____UNSAFE_GET_USER_INC(to, from, u_or_s##16, label); \
+ break; \
+ case 4: \
+ ____UNSAFE_GET_USER_INC(to, from, u_or_s##32, label); \
+ break; \
+ default: \
+ return -EFAULT; \
+ } \
+})
+
+#define UNSAFE_GET_USER_UNSIGNED_INC(to, from, size, label) \
+ __UNSAFE_GET_USER_INC(to, from, size, label, u)
+
+#define UNSAFE_GET_USER_SIGNED_INC(to, from, size, label) \
+ __UNSAFE_GET_USER_INC(to, from, size, label, s)
+
+#define UNSAFE_GET_USER_INC(to, from, size, label) \
+ _Generic(to, \
+ u8 : UNSAFE_GET_USER_UNSIGNED_INC(to, from, size, label), \
+ u16 : UNSAFE_GET_USER_UNSIGNED_INC(to, from, size, label), \
+ u32 : UNSAFE_GET_USER_UNSIGNED_INC(to, from, size, label), \
+ s8 : UNSAFE_GET_USER_SIGNED_INC(to, from, size, label), \
+ s16 : UNSAFE_GET_USER_SIGNED_INC(to, from, size, label), \
+ s32 : UNSAFE_GET_USER_SIGNED_INC(to, from, size, label))
+
+static __always_inline int __read_fre(struct sframe_section *sec,
+ struct sframe_fde_internal *fde,
+ unsigned long fre_addr,
+ struct sframe_fre_internal *fre)
+{
+ unsigned char fde_type = SFRAME_FUNC_FDE_TYPE(fde->info);
+ unsigned char fre_type = SFRAME_FUNC_FRE_TYPE(fde->info);
+ unsigned char offset_count, offset_size;
+ s32 cfa_off, ra_off, fp_off;
+ unsigned long cur = fre_addr;
+ unsigned char addr_size;
+ u32 ip_off;
+ u8 info;
+
+ addr_size = fre_type_to_size(fre_type);
+ if (!addr_size)
+ return -EFAULT;
+
+ if (fre_addr + addr_size + 1 > sec->fres_end)
+ return -EFAULT;
+
+ UNSAFE_GET_USER_INC(ip_off, cur, addr_size, Efault);
+ if (fde_type == SFRAME_FDE_TYPE_PCINC && ip_off > fde->func_size)
+ return -EFAULT;
+
+ UNSAFE_GET_USER_INC(info, cur, 1, Efault);
+ offset_count = SFRAME_FRE_OFFSET_COUNT(info);
+ offset_size = offset_size_enum_to_size(SFRAME_FRE_OFFSET_SIZE(info));
+ if (!offset_count || !offset_size)
+ return -EFAULT;
+
+ if (cur + (offset_count * offset_size) > sec->fres_end)
+ return -EFAULT;
+
+ fre->size = addr_size + 1 + (offset_count * offset_size);
+
+ UNSAFE_GET_USER_INC(cfa_off, cur, offset_size, Efault);
+ offset_count--;
+
+ ra_off = sec->ra_off;
+ if (!ra_off) {
+ if (!offset_count--)
+ return -EFAULT;
+
+ UNSAFE_GET_USER_INC(ra_off, cur, offset_size, Efault);
+ }
-#define dbg(fmt, ...) \
- pr_debug("%s (%d): " fmt, current->comm, current->pid, ##__VA_ARGS__)
+ fp_off = sec->fp_off;
+ if (!fp_off && offset_count) {
+ offset_count--;
+ UNSAFE_GET_USER_INC(fp_off, cur, offset_size, Efault);
+ }
+
+ if (offset_count)
+ return -EFAULT;
+
+ fre->ip_off = ip_off;
+ fre->cfa_off = cfa_off;
+ fre->ra_off = ra_off;
+ fre->fp_off = fp_off;
+ fre->info = info;
+
+ return 0;
+
+Efault:
+ return -EFAULT;
+}
+
+static __always_inline int __find_fre(struct sframe_section *sec,
+ struct sframe_fde_internal *fde,
+ unsigned long ip,
+ struct unwind_user_frame *frame)
+{
+ unsigned char fde_type = SFRAME_FUNC_FDE_TYPE(fde->info);
+ struct sframe_fre_internal *fre, *prev_fre = NULL;
+ struct sframe_fre_internal fres[2];
+ unsigned long fre_addr;
+ bool which = false;
+ unsigned int i;
+ u32 ip_off;
+
+ ip_off = ip - fde->func_start_addr;
+
+ if (fde_type == SFRAME_FDE_TYPE_PCMASK)
+ ip_off %= fde->rep_size;
+
+ fre_addr = sec->fres_start + fde->fres_off;
+
+ for (i = 0; i < fde->fres_num; i++) {
+ int ret;
+
+ /*
+ * Alternate between the two fre_addr[] entries for 'fre' and
+ * 'prev_fre'.
+ */
+ fre = which ? fres : fres + 1;
+ which = !which;
+
+ ret = __read_fre(sec, fde, fre_addr, fre);
+ if (ret)
+ return ret;
+
+ fre_addr += fre->size;
+
+ if (prev_fre && fre->ip_off <= prev_fre->ip_off)
+ return -EFAULT;
+
+ if (fre->ip_off > ip_off)
+ break;
+
+ prev_fre = fre;
+ }
+
+ if (!prev_fre)
+ return -EINVAL;
+ fre = prev_fre;
+
+ frame->cfa_off = fre->cfa_off;
+ frame->ra_off = fre->ra_off;
+ frame->fp_off = fre->fp_off;
+ frame->use_fp = SFRAME_FRE_CFA_BASE_REG_ID(fre->info) == SFRAME_BASE_REG_FP;
+
+ return 0;
+}
+
+int sframe_find(unsigned long ip, struct unwind_user_frame *frame)
+{
+ struct mm_struct *mm = current->mm;
+ struct sframe_section *sec;
+ struct sframe_fde_internal fde;
+ int ret;
+
+ if (!mm)
+ return -EINVAL;
+
+ guard(srcu)(&sframe_srcu);
+
+ sec = mtree_load(&mm->sframe_mt, ip);
+ if (!sec)
+ return -EINVAL;
+
+ if (!user_read_access_begin((void __user *)sec->sframe_start,
+ sec->sframe_end - sec->sframe_start))
+ return -EFAULT;
+
+ ret = __find_fde(sec, ip, &fde);
+ if (ret)
+ goto end;
+
+ ret = __find_fre(sec, &fde, ip, frame);
+end:
+ user_read_access_end();
+ return ret;
+}
static void free_section(struct sframe_section *sec)
{
@@ -120,8 +433,10 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
sec->text_end = text_end;
ret = sframe_read_header(sec);
- if (ret)
+ if (ret) {
+ dbg_print_header(sec);
goto err_free;
+ }
ret = mtree_insert_range(sframe_mt, sec->text_start, sec->text_end, sec, GFP_KERNEL);
if (ret) {
@@ -137,6 +452,13 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end,
return ret;
}
+static void sframe_free_srcu(struct rcu_head *rcu)
+{
+ struct sframe_section *sec = container_of(rcu, struct sframe_section, rcu);
+
+ free_section(sec);
+}
+
static int __sframe_remove_section(struct mm_struct *mm,
struct sframe_section *sec)
{
@@ -145,7 +467,7 @@ static int __sframe_remove_section(struct mm_struct *mm,
return -EINVAL;
}
- free_section(sec);
+ call_srcu(&sframe_srcu, &sec->rcu, sframe_free_srcu);
return 0;
}
diff --git a/kernel/unwind/sframe_debug.h b/kernel/unwind/sframe_debug.h
new file mode 100644
index 000000000000..055c8c8fae24
--- /dev/null
+++ b/kernel/unwind/sframe_debug.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SFRAME_DEBUG_H
+#define _SFRAME_DEBUG_H
+
+#include <linux/sframe.h>
+#include "sframe.h"
+
+#ifdef CONFIG_DYNAMIC_DEBUG
+
+#define dbg(fmt, ...) \
+ pr_debug("%s (%d): " fmt, current->comm, current->pid, ##__VA_ARGS__)
+
+static __always_inline void dbg_print_header(struct sframe_section *sec)
+{
+ unsigned long fdes_end;
+
+ fdes_end = sec->fdes_start + (sec->num_fdes * sizeof(struct sframe_fde));
+
+ dbg("SEC: sframe:0x%lx-0x%lx text:0x%lx-0x%lx "
+ "fdes:0x%lx-0x%lx fres:0x%lx-0x%lx "
+ "ra_off:%d fp_off:%d\n",
+ sec->sframe_start, sec->sframe_end, sec->text_start, sec->text_end,
+ sec->fdes_start, fdes_end, sec->fres_start, sec->fres_end,
+ sec->ra_off, sec->fp_off);
+}
+
+#else /* !CONFIG_DYNAMIC_DEBUG */
+
+#define dbg(args...) no_printk(args)
+
+static inline void dbg_print_header(struct sframe_section *sec) {}
+
+#endif /* !CONFIG_DYNAMIC_DEBUG */
+
+#endif /* _SFRAME_DEBUG_H */
--
2.48.1
^ permalink raw reply related
* Re: [PATCH v3 3/8] mm: implement sticky VMA flags
From: Pedro Falcato @ 2025-11-19 13:27 UTC (permalink / raw)
To: Mark Brown
Cc: Lorenzo Stoakes, Andrew Morton, Jonathan Corbet,
David Hildenbrand, Liam R . Howlett, Vlastimil Babka,
Mike Rapoport, Suren Baghdasaryan, Michal Hocko, Steven Rostedt,
Masami Hiramatsu, Mathieu Desnoyers, Jann Horn, Zi Yan,
Baolin Wang, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, linux-kernel, linux-fsdevel, linux-doc, linux-mm,
linux-trace-kernel, linux-kselftest, Andrei Vagin, Aishwarya.TCV
In-Reply-To: <25cb4b6a-035b-4193-a8db-685fc4c58507@sirena.org.uk>
On Wed, Nov 19, 2025 at 01:16:36PM +0000, Mark Brown wrote:
> On Fri, Nov 07, 2025 at 04:11:48PM +0000, Lorenzo Stoakes wrote:
> > It is useful to be able to designate that certain flags are 'sticky', that
> > is, if two VMAs are merged one with a flag of this nature and one without,
> > the merged VMA sets this flag.
>
> I'm seeing regressions on multiple arm64 platforms in at least the LTP
> clone302 and madvise10 selftests, both of which have bisected to one of
> the fixups to this patch. Especially given the other tests that also
> bisected to the same place I've not investigated further. There's a
> number of other LTP tests that started failing today including relevant
> seeming ones munlockall01, mprotect04, madvise10, mprotect03 and
> futex_cmp_requeue01 but I don't have bisects to confirm they're the same
> thing.
>
Thanks for the reports!
> clone302:
>
> tst_buffers.c:57: TINFO: Test is using guarded buffers
> tst_tmpdir.c:316: TINFO: Using /tmp/LTP_clorMwMMw as tmpdir (nfs filesystem)
> tst_test.c:1953: TINFO: LTP version: 20250530
> tst_test.c:1956: TINFO: Tested kernel: 6.18.0-rc6-next-20251119 #1 SMP PREEMPT @1763523415 aarch64
next-20251119 still has the v3 version of the patchset, which is Known Bad(tm)
after a couple of buggy fixups. v4 should hopefully work properly.
--
Pedro
^ permalink raw reply
* Re: [PATCH v3 3/8] mm: implement sticky VMA flags
From: Lorenzo Stoakes @ 2025-11-19 13:37 UTC (permalink / raw)
To: Mark Brown
Cc: Andrew Morton, Jonathan Corbet, David Hildenbrand,
Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Steven Rostedt,
Masami Hiramatsu, Mathieu Desnoyers, Jann Horn, Pedro Falcato,
Zi Yan, Baolin Wang, Nico Pache, Ryan Roberts, Dev Jain,
Barry Song, Lance Yang, linux-kernel, linux-fsdevel, linux-doc,
linux-mm, linux-trace-kernel, linux-kselftest, Andrei Vagin,
Aishwarya.TCV
In-Reply-To: <2ab7be71-716a-40c0-adb7-01e7474546d0@sirena.org.uk>
On Wed, Nov 19, 2025 at 12:55:29PM +0000, Mark Brown wrote:
> On Fri, Nov 07, 2025 at 04:11:48PM +0000, Lorenzo Stoakes wrote:
> > It is useful to be able to designate that certain flags are 'sticky', that
> > is, if two VMAs are merged one with a flag of this nature and one without,
> > the merged VMA sets this flag.
>
> I'm seeing a regression in the futex selftests on arm64:
>
> # TAP version 13
> # 1..1
> # # Starting 1 tests from 1 test cases.
> # # RUN global.futex_numa_mpol ...
> # # Regular test
> # # Mis-aligned futex
> # # Memory out of range
> # Bail out! futex2_wake(64, 0x86) should fail, but didn't
> # # Planned tests != run tests (1 != 0)
> # # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0
> # # futex_numa_mpol: Test failed
> # # FAIL global.futex_numa_mpol
> # not ok 1 global.futex_numa_mpol
> # # FAILED: 0 / 1 tests passed.
>
> which bisect to one of the fixup commits on top of this. I've not done
> any real analysis on this but it's a test that's generally very stable
> so I'd be surprised if it's not a real failure.
Yeah the fixups are known-buggy, apologies (non-fixups are buggy also but in a
way that'll be less visible from tests :). I sent a v4 which resolves
everything, see [0].
[0]: https://lore.kernel.org/all/cover.1763460113.git.lorenzo.stoakes@oracle.com/
This should land in linux-next relatively soon if not already there.
Cheers, Lorenzo
>
> Full log:
>
> https://lava.sirena.org.uk/scheduler/job/2106243#L11474
>
> There is also a bisection for the mm mkdirty selftest which runs into
> the same patch on at least Raspberry Pi 4:
>
> # # -----------------
> # # running ./mkdirty
> # # -----------------
> # # # [INFO] detected THP size: 2048 KiB
> # # TAP version 13
> # # 1..6
> # # # [INFO] PTRACE write access
> # # ok 1 SIGSEGV generated, page not modified
> # # # [INFO] PTRACE write access to THP
> # # ok 2 SIGSEGV generated, page not modified
> # # # [INFO] Page migration
> # # not ok 3 SIGSEGV generated, page not modified
> # # # [INFO] Page migration of THP
> # # not ok 4 SIGSEGV generated, page not modified
> # # # [INFO] PTE-mapping a THP
> # # not ok 5 SIGSEGV generated, page not modified
> # # # [INFO] UFFDIO_COPY
> # # ok 6 # SKIP __NR_userfaultfd failed
> # # Bail out! 3 out of 6 tests failed
> # # # 1 skipped test(s) detected. Consider enabling relevant config options to improve coverage.
> # # # Totals: pass:2 fail:3 xfail:0 xpass:0 skip:1 error:0
> # # [FAIL]
> # not ok 61 mkdirty # exit=1
>
> Full log for that:
>
> https://lava.sirena.org.uk/scheduler/job/2106236#L6939
>
> and I'm also seeing some LTP failures going into these commits that I'll
> report separately.
>
> bisect log for the futex test:
>
> # bad: [fe4d0dea039f2befb93f27569593ec209843b0f5] Add linux-next specific files for 20251119
> # good: [ef96b7dd050abd62905588c41ffb397e0c9598c7] Merge branch 'for-linux-next-fixes' of https://gitlab.freedesktop.org/drm/misc/kernel.git
> # good: [bd79452b39c21599e2cff42e9fbeb182656b6f6a] MAINTAINERS: adjust file entry in RISC-V MICROCHIP SUPPORT
> # good: [21e68bcb1b0c688c2d9ca0d457922febac650ac1] regulator: renesas-usb-vbus-regulator: Remove unused headers
> # good: [96498e804cb6629e02747336a0a33e4955449732] spi: davinci: remove platform data header
> # good: [4422df6782eb7aa9725a3c09d9ba3c38ecc85df4] ASoC: ux500: mop500_ab8500: convert to snd_soc_dapm_xxx()
> # good: [9e510e677090bb794b46348b10e1c8038286e00a] spi: aspeed: Add support for the AST2700 SPI controller
> # good: [118eb2cb97b8fc0d515bb0449495959247db58f0] spi: bcm63xx: drop wrong casts in probe()
> # good: [d5c8b7902a41625ea328b52c78ebe750fbf6fef7] ASoC: Intel: avs: Honor NHLT override when setting up a path
> # good: [6402ddf3027d8975f135cf2b2014d6bbeb2d3436] MAINTAINERS: refer to trivial-codec.yaml in relevant sections
> # good: [059f545832be85d29ac9ccc416a16f647aa78485] spi: add support for microchip "soft" spi controller
> # good: [4e00135b2dd1d7924a58bffa551b6ceb3bd836f2] spi: spi-cadence: supports transmission with bits_per_word of 16 and 32
> # good: [e65b871c9b5af9265aefc5b8cd34993586d93aab] ASoC: codecs: pm4125: Remove irq_chip on component unbind
> # good: [8d63e85c5b50f1dbfa0ccb214bd91fe5d7e2e860] firmware: cs_dsp: fix kernel-doc warnings in a header file
> # good: [8ff3dcb0e8a8bf6c41f23ed4aa62d066d3948a10] ASoC: codecs: lpass-rx-macro: add SM6115 compatible
> # good: [123cd174a3782307787268adf45f22de4d290128] ASoC: Intel: atom: Replace strcpy() with strscpy()
> # good: [1d562ba0aa7df81335bf96c02be77efe8d5bab87] spi: dt-bindings: nuvoton,npcm-pspi: Convert to DT schema
> # good: [4d6e2211aeb932e096f673c88475016b1cc0f8ab] ASoC: Intel: boards: fix HDMI playback lookup when HDMI-In capture used
> # good: [32172cf3cb543a04c41a1677c97a38e60cad05b6] ASoC: cs35l56: Allow restoring factory calibration through ALSA control
> # good: [b3a5302484033331af37569f7277d00131694b57] ASoC: Intel: sof_rt5682: Add quirk override support
> # good: [873bc94689d832878befbcadc10b6ad5bb4e0027] ASoC: Intel: sof_sdw: add codec speaker support for the SKU
> # good: [772ada50282b0c80343c8989147db816961f571d] ASoC: cs35l56: Alter error codes for calibration routine
> # good: [6985defd1d832f1dd9d1977a6a2cc2cef7632704] regmap: sdw-mbq: Reorder regmap_mbq_context struct for better packing
> # good: [fb1ebb10468da414d57153ddebaab29c38ef1a78] regulator: core: disable supply if enabling main regulator fails
> # good: [2089f086303b773e181567fd8d5df3038bd85937] regulator: mt6363: Remove unneeded semicolon
> # good: [6951be397ca8b8b167c9f99b5a11c541148c38cb] ASoC: codecs: pm4125: remove duplicate code
> # good: [4e92abd0a11b91af3742197a9ca962c3c00d0948] spi: imx: add i.MX51 ECSPI target mode support
> # good: [abc9a349b87ac0fd3ba8787ca00971b59c2e1257] spi: fsl-qspi: support the SpacemiT K1 SoC
> # good: [55d03b5b5bdd04daf9a35ce49db18d8bb488dffb] spi: imx: remove CLK calculation and check for target mode
> # good: [6bd1ad97eb790570c167d4de4ca59fbc9c33722a] regulator: pf9453: Fix kernel doc for mux_poll()
> # good: [1b0f3f9ee41ee2bdd206667f85ea2aa36dfe6e69] ASoC: SDCA: support Q7.8 volume format
> # good: [3c36965df80801344850388592e95033eceea05b] regulator: Add support for MediaTek MT6363 SPMI PMIC Regulators
> # good: [2f538ef9f6f7c3d700c68536f21447dfc598f8c8] spi: aspeed: Use devm_iounmap() to unmap devm_ioremap() memory
> # good: [aa897ffc396b48cc39eee133b6b43175d0df9eb5] ASoC: dt-bindings: ti,pcm1862: convert to dtschema
> # good: [655079ac8a7721ac215a0596e3f33b740e01144a] ASoC: qcom: q6asm: Use guard() for spin locks
> # good: [c4e68959af66df525d71db619ffe44af9178bb22] ASoC: dt-bindings: ti,tas2781: Add TAS5822 support
> # good: [380fd29d57abe6679d87ec56babe65ddc5873a37] spi: tegra210-quad: Check hardware status on timeout
> # good: [af9c8092d84244ca54ffb590435735f788e7a170] regmap: i3c: Use ARRAY_SIZE()
> # good: [84194c66aaf78fed150edb217b9f341518b1cba2] ASoC: codecs: aw88261: pass pointer directly instead of passing the address
> # good: [252abf2d07d33b1c70a59ba1c9395ba42bbd793e] regulator: Small cleanup in of_get_regulation_constraints()
> # good: [2ecc8c089802e033d2e5204d21a9f467e2517df9] regulator: pf9453: remove unused I2C_LT register
> # good: [ed5d499b5c9cc11dd3edae1a7a55db7dfa4f1bdc] regcache: maple: Split ->populate() from ->init()
> # good: [e73b743bfe8a6ff4e05b5657d3f7586a17ac3ba0] ASoC: soc-core: check ops & auto_selectable_formats in snd_soc_dai_get_fmt() to prevent dereference error
> # good: [f1dfbc1b5cf8650ae9a0d543e5f5335fc0f478ce] ASoC: max98090/91: fixing the stream index
> # good: [ecd0de438c1f0ee86cf8f6d5047965a2a181444b] spi: tle62x0: Add newline to sysfs attribute output
> # good: [6ef8e042cdcaabe3e3c68592ba8bfbaee2fa10a3] ASoC: codec: wm8400: replace printk() calls with dev_*() device aware logging
> # good: [20bcda681f8597e86070a4b3b12d1e4f541865d3] ASoC: codecs: va-macro: fix revision checking
> # good: [cf6bf51b53252284bafc7377a4d8dbf10f048b4d] ASoC: cs4271: Add support for the external mclk
> # good: [28039efa4d8e8bbf98b066133a906bd4e307d496] MAINTAINERS: remove obsolete file entry in DIALOG SEMICONDUCTOR DRIVERS
> # good: [e062bdfdd6adbb2dee7751d054c1d8df63ddb8b8] regmap: warn users about uninitialized flat cache
> # good: [8fdb030fe283c84fd8d378c97ad0f32d6cdec6ce] ASoC: qcom: sc7280: make use of common helpers
> # good: [66fecfa91deb536a12ddf3d878a99590d7900277] ASoC: spacemit: use `depends on` instead of `select`
> # good: [f034c16a4663eaf3198dc18b201ba50533fb5b81] ASoC: spacemit: add failure check for spacemit_i2s_init_dai()
> # good: [4a5ac6cd05a7e54f1585d7779464d6ed6272c134] ASoC: sun4i-spdif: Support SPDIF output on A523 family
> # good: [ef042df96d0e1089764f39ede61bc8f140a4be00] ASoC: SDCA: Add HID button IRQ
> # good: [4c33cef58965eb655a0ac8e243aa323581ec025f] regulator: pca9450: link regulator inputs to supply groups
> # good: [01313661b248c5ba586acae09bff57077dbec0a5] regulator: Let raspberrypi drivers depend on ARM
> # good: [e7434adf0c53a84d548226304cdb41c8818da1cb] ASoC: cs530x: Add SPI bus support for cs530x parts
> # good: [77a58ba7c64ccca20616aa03599766ccb0d1a330] spi: spi-mem: Trace exec_op
> # good: [4795375d8aa072e9aacb0b278e6203c6ca41816a] ASoC: cs-amp-lib-test: Add test cases for cs_amp_set_efi_calibration_data()
> # good: [d29479abaded34b2b1dab2e17efe96a65eba3d61] ASoC: renesas: fsi: Constify struct fsi_stream_handler
> # good: [e973dfe9259095fb509ab12658c68d46f0e439d7] ASoC: qcom: sm8250: add qrb2210-sndcard compatible string
> # good: [c17fa4cbc546c431ccf13e9354d5d9c1cd247b7c] ASoC: sdw_utils: add name_prefix for rt1321 part id
> # good: [2528c15f314ece50218d1273654f630d74109583] ASoC: max98090/91: adding DAPM routing for digital output for max98091
> # good: [d054cc3a2ccfb19484f3b54d69b6e416832dc8f4] regulator: rpmh-regulator: Add RPMH regulator support for PMR735D
> # good: [310bf433c01f78e0756fd5056a43118a2f77318c] ASoC: max98090/91: fixing a space
> # good: [fd5ef3d69f8975bad16c437a337b5cb04c8217a2] spi: spi-qpic-snand: make qcom_spi_ecc_engine_ops_pipelined const
> # good: [638bae3fb225a708dc67db613af62f6d14c4eff4] ASoC: max98090/91: added DAPM widget for digital output for max98091
> # good: [ecba655bf54a661ffe078856cd8dbc898270e4b5] ASoC: fsl_aud2htx: add IEC958_SUBFRAME_LE format in supported list
> # good: [7e1906643a7374529af74b013bba35e4fa4e6ffc] ASoC: codecs: va-macro: Clean up on error path in probe()
> # good: [d742ebcfe524dc54023f7c520d2ed2e4b7203c19] ASoC: soc.h: remove snd_soc_kcontrol_component()
> # good: [6658472a3e2de08197acfe099ba71ee0e2505ecf] ASoC: amd: amd_sdw: Propagate the PCI subsystem Vendor and Device IDs
> # good: [fce217449075d59b29052b8cdac567f0f3e22641] ASoC: spacemit: add i2s support for K1 SoC
> # good: [0cc08c8130ac8f74419f99fe707dc193b7f79d86] spi: aspeed: Fix an IS_ERR() vs NULL bug in probe()
> # good: [0743acf746a81e0460a56fd5ff847d97fa7eb370] spi: airoha: buffer must be 0xff-ed before writing
> # good: [d77daa49085b067137d0adbe3263f75a7ee13a1b] spi: aspeed: fix spelling mistake "triming" -> "trimming"
> # good: [15afe57a874eaf104bfbb61ec598fa31627f7b19] ASoC: dt-bindings: qcom: Add Kaanapali LPASS macro codecs
> # good: [1e570e77392f43a3cdab2849d1f81535f8a033e2] ASoC: mxs-saif: support usage with simple-audio-card
> # good: [fb25114cd760c13cf177d9ac37837fafcc9657b5] regulator: sy7636a: add gpios and input regulator
> # good: [6621b0f118d500092f5f3d72ddddb22aeeb3c3a0] ASoC: codecs: rt5670: use SOC_VALUE_ENUM_SINGLE_DECL for DAC2 L/R MX-1B
> # good: [65efe5404d151767653c7b7dd39bd2e7ad532c2d] regulator: rpmh-regulator: Add RPMH regulator support for Glymur
> # good: [433e294c3c5b5d2020085a0e36c1cb47b694690a] regulator: core: forward undervoltage events downstream by default
> # good: [0b0eb7702a9fa410755e86124b4b7cd36e7d1cb4] ASoC: replace use of system_wq with system_dfl_wq
> # good: [bf770d6d2097a52d87f4d9c88d0b05bd3998d7de] x86/module: Improve relocation error messages
> # good: [c2d420796a427dda71a2400909864e7f8e037fd4] elfnote: Change ELFNOTE() to use __UNIQUE_ID()
> # good: [7e7e2c6e2a1cb250f8d03bb99eed01f6d982d5dd] ASoC: sof-function-topology-lib: escalate the log when missing function topoplogy
> # good: [64d87ccfae3326a9561fe41dc6073064a083e0df] spi: aspeed: Only map necessary address window region
> # good: [4d410ba9aa275e7990a270f63ce436990ace1bea] dt-bindings: sound: Update ADMAIF bindings for tegra264
> # good: [5e537031f322d55315cd384398b726a9a0748d47] ASoC: codecs: Fix the error of excessive semicolons
> # good: [4412ab501677606436e5c49e41151a1e6eac7ac0] spi: dt-bindings: spi-qpic-snand: Add IPQ5332 compatible
> # good: [9797329220a2c6622411eb9ecf6a35b24ce09d04] ASoC: sof-function-topology-lib: escalate the log when missing function topoplogy
> # good: [fe8cc44dd173cde5788ab4e3730ac61f3d316d9c] spi: dw: add target mode support
> # good: [6277a486a7faaa6c87f4bf1d59a2de233a093248] regulator: dt-bindings: Convert Dialog DA9211 Regulators to DT schema
> # good: [b83fb1b14c06bdd765903ac852ba20a14e24f227] spi: offload: Add offset parameter
> git bisect start 'fe4d0dea039f2befb93f27569593ec209843b0f5' 'ef96b7dd050abd62905588c41ffb397e0c9598c7' 'bd79452b39c21599e2cff42e9fbeb182656b6f6a' '21e68bcb1b0c688c2d9ca0d457922febac650ac1' '96498e804cb6629e02747336a0a33e4955449732' '4422df6782eb7aa9725a3c09d9ba3c38ecc85df4' '9e510e677090bb794b46348b10e1c8038286e00a' '118eb2cb97b8fc0d515bb0449495959247db58f0' 'd5c8b7902a41625ea328b52c78ebe750fbf6fef7' '6402ddf3027d8975f135cf2b2014d6bbeb2d3436' '059f545832be85d29ac9ccc416a16f647aa78485' '4e00135b2dd1d7924a58bffa551b6ceb3bd836f2' 'e65b871c9b5af9265aefc5b8cd34993586d93aab' '8d63e85c5b50f1dbfa0ccb214bd91fe5d7e2e860' '8ff3dcb0e8a8bf6c41f23ed4aa62d066d3948a10' '123cd174a3782307787268adf45f22de4d290128' '1d562ba0aa7df81335bf96c02be77efe8d5bab87' '4d6e2211aeb932e096f673c88475016b1cc0f8ab' '32172cf3cb543a04c41a1677c97a38e60cad05b6' 'b3a5302484033331af37569f7277d00131694b57' '873bc94689d832878befbcadc10b6ad5bb4e0027' '772ada50282b0c80343c8989147db816961f571d' '6985defd1d832f1dd9d1977a6a2cc2cef7632704' 'fb1ebb10468da414d57153ddebaab29c38ef1a78' '2089f086303b773e181567fd8d5df3038bd85937' '6951be397ca8b8b167c9f99b5a11c541148c38cb' '4e92abd0a11b91af3742197a9ca962c3c00d0948' 'abc9a349b87ac0fd3ba8787ca00971b59c2e1257' '55d03b5b5bdd04daf9a35ce49db18d8bb488dffb' '6bd1ad97eb790570c167d4de4ca59fbc9c33722a' '1b0f3f9ee41ee2bdd206667f85ea2aa36dfe6e69' '3c36965df80801344850388592e95033eceea05b' '2f538ef9f6f7c3d700c68536f21447dfc598f8c8' 'aa897ffc396b48cc39eee133b6b43175d0df9eb5' '655079ac8a7721ac215a0596e3f33b740e01144a' 'c4e68959af66df525d71db619ffe44af9178bb22' '380fd29d57abe6679d87ec56babe65ddc5873a37' 'af9c8092d84244ca54ffb590435735f788e7a170' '84194c66aaf78fed150edb217b9f341518b1cba2' '252abf2d07d33b1c70a59ba1c9395ba42bbd793e' '2ecc8c089802e033d2e5204d21a9f467e2517df9' 'ed5d499b5c9cc11dd3edae1a7a55db7dfa4f1bdc' 'e73b743bfe8a6ff4e05b5657d3f7586a17ac3ba0' 'f1dfbc1b5cf8650ae9a0d543e5f5335fc0f478ce' 'ecd0de438c1f0ee86cf8f6d5047965a2a181444b' '6ef8e042cdcaabe3e3c68592ba8bfbaee2fa10a3' '20bcda681f8597e86070a4b3b12d1e4f541865d3' 'cf6bf51b53252284bafc7377a4d8dbf10f048b4d' '28039efa4d8e8bbf98b066133a906bd4e307d496' 'e062bdfdd6adbb2dee7751d054c1d8df63ddb8b8' '8fdb030fe283c84fd8d378c97ad0f32d6cdec6ce' '66fecfa91deb536a12ddf3d878a99590d7900277' 'f034c16a4663eaf3198dc18b201ba50533fb5b81' '4a5ac6cd05a7e54f1585d7779464d6ed6272c134' 'ef042df96d0e1089764f39ede61bc8f140a4be00' '4c33cef58965eb655a0ac8e243aa323581ec025f' '01313661b248c5ba586acae09bff57077dbec0a5' 'e7434adf0c53a84d548226304cdb41c8818da1cb' '77a58ba7c64ccca20616aa03599766ccb0d1a330' '4795375d8aa072e9aacb0b278e6203c6ca41816a' 'd29479abaded34b2b1dab2e17efe96a65eba3d61' 'e973dfe9259095fb509ab12658c68d46f0e439d7' 'c17fa4cbc546c431ccf13e9354d5d9c1cd247b7c' '2528c15f314ece50218d1273654f630d74109583' 'd054cc3a2ccfb19484f3b54d69b6e416832dc8f4' '310bf433c01f78e0756fd5056a43118a2f77318c' 'fd5ef3d69f8975bad16c437a337b5cb04c8217a2' '638bae3fb225a708dc67db613af62f6d14c4eff4' 'ecba655bf54a661ffe078856cd8dbc898270e4b5' '7e1906643a7374529af74b013bba35e4fa4e6ffc' 'd742ebcfe524dc54023f7c520d2ed2e4b7203c19' '6658472a3e2de08197acfe099ba71ee0e2505ecf' 'fce217449075d59b29052b8cdac567f0f3e22641' '0cc08c8130ac8f74419f99fe707dc193b7f79d86' '0743acf746a81e0460a56fd5ff847d97fa7eb370' 'd77daa49085b067137d0adbe3263f75a7ee13a1b' '15afe57a874eaf104bfbb61ec598fa31627f7b19' '1e570e77392f43a3cdab2849d1f81535f8a033e2' 'fb25114cd760c13cf177d9ac37837fafcc9657b5' '6621b0f118d500092f5f3d72ddddb22aeeb3c3a0' '65efe5404d151767653c7b7dd39bd2e7ad532c2d' '433e294c3c5b5d2020085a0e36c1cb47b694690a' '0b0eb7702a9fa410755e86124b4b7cd36e7d1cb4' 'bf770d6d2097a52d87f4d9c88d0b05bd3998d7de' 'c2d420796a427dda71a2400909864e7f8e037fd4' '7e7e2c6e2a1cb250f8d03bb99eed01f6d982d5dd' '64d87ccfae3326a9561fe41dc6073064a083e0df' '4d410ba9aa275e7990a270f63ce436990ace1bea' '5e537031f322d55315cd384398b726a9a0748d47' '4412ab501677606436e5c49e41151a1e6eac7ac0' '9797329220a2c6622411eb9ecf6a35b24ce09d04' 'fe8cc44dd173cde5788ab4e3730ac61f3d316d9c' '6277a486a7faaa6c87f4bf1d59a2de233a093248' 'b83fb1b14c06bdd765903ac852ba20a14e24f227'
> # test job: [bd79452b39c21599e2cff42e9fbeb182656b6f6a] https://lava.sirena.org.uk/scheduler/job/2104091
> # test job: [21e68bcb1b0c688c2d9ca0d457922febac650ac1] https://lava.sirena.org.uk/scheduler/job/2104499
> # test job: [96498e804cb6629e02747336a0a33e4955449732] https://lava.sirena.org.uk/scheduler/job/2099744
> # test job: [4422df6782eb7aa9725a3c09d9ba3c38ecc85df4] https://lava.sirena.org.uk/scheduler/job/2097747
> # test job: [9e510e677090bb794b46348b10e1c8038286e00a] https://lava.sirena.org.uk/scheduler/job/2095684
> # test job: [118eb2cb97b8fc0d515bb0449495959247db58f0] https://lava.sirena.org.uk/scheduler/job/2092525
> # test job: [d5c8b7902a41625ea328b52c78ebe750fbf6fef7] https://lava.sirena.org.uk/scheduler/job/2092722
> # test job: [6402ddf3027d8975f135cf2b2014d6bbeb2d3436] https://lava.sirena.org.uk/scheduler/job/2086597
> # test job: [059f545832be85d29ac9ccc416a16f647aa78485] https://lava.sirena.org.uk/scheduler/job/2086754
> # test job: [4e00135b2dd1d7924a58bffa551b6ceb3bd836f2] https://lava.sirena.org.uk/scheduler/job/2082525
> # test job: [e65b871c9b5af9265aefc5b8cd34993586d93aab] https://lava.sirena.org.uk/scheduler/job/2083134
> # test job: [8d63e85c5b50f1dbfa0ccb214bd91fe5d7e2e860] https://lava.sirena.org.uk/scheduler/job/2082576
> # test job: [8ff3dcb0e8a8bf6c41f23ed4aa62d066d3948a10] https://lava.sirena.org.uk/scheduler/job/2083116
> # test job: [123cd174a3782307787268adf45f22de4d290128] https://lava.sirena.org.uk/scheduler/job/2078967
> # test job: [1d562ba0aa7df81335bf96c02be77efe8d5bab87] https://lava.sirena.org.uk/scheduler/job/2078346
> # test job: [4d6e2211aeb932e096f673c88475016b1cc0f8ab] https://lava.sirena.org.uk/scheduler/job/2078001
> # test job: [32172cf3cb543a04c41a1677c97a38e60cad05b6] https://lava.sirena.org.uk/scheduler/job/2075073
> # test job: [b3a5302484033331af37569f7277d00131694b57] https://lava.sirena.org.uk/scheduler/job/2074546
> # test job: [873bc94689d832878befbcadc10b6ad5bb4e0027] https://lava.sirena.org.uk/scheduler/job/2074833
> # test job: [772ada50282b0c80343c8989147db816961f571d] https://lava.sirena.org.uk/scheduler/job/2069152
> # test job: [6985defd1d832f1dd9d1977a6a2cc2cef7632704] https://lava.sirena.org.uk/scheduler/job/2059121
> # test job: [fb1ebb10468da414d57153ddebaab29c38ef1a78] https://lava.sirena.org.uk/scheduler/job/2059787
> # test job: [2089f086303b773e181567fd8d5df3038bd85937] https://lava.sirena.org.uk/scheduler/job/2058104
> # test job: [6951be397ca8b8b167c9f99b5a11c541148c38cb] https://lava.sirena.org.uk/scheduler/job/2055777
> # test job: [4e92abd0a11b91af3742197a9ca962c3c00d0948] https://lava.sirena.org.uk/scheduler/job/2055848
> # test job: [abc9a349b87ac0fd3ba8787ca00971b59c2e1257] https://lava.sirena.org.uk/scheduler/job/2054637
> # test job: [55d03b5b5bdd04daf9a35ce49db18d8bb488dffb] https://lava.sirena.org.uk/scheduler/job/2053889
> # test job: [6bd1ad97eb790570c167d4de4ca59fbc9c33722a] https://lava.sirena.org.uk/scheduler/job/2053541
> # test job: [1b0f3f9ee41ee2bdd206667f85ea2aa36dfe6e69] https://lava.sirena.org.uk/scheduler/job/2053565
> # test job: [3c36965df80801344850388592e95033eceea05b] https://lava.sirena.org.uk/scheduler/job/2049494
> # test job: [2f538ef9f6f7c3d700c68536f21447dfc598f8c8] https://lava.sirena.org.uk/scheduler/job/2048656
> # test job: [aa897ffc396b48cc39eee133b6b43175d0df9eb5] https://lava.sirena.org.uk/scheduler/job/2048772
> # test job: [655079ac8a7721ac215a0596e3f33b740e01144a] https://lava.sirena.org.uk/scheduler/job/2049697
> # test job: [c4e68959af66df525d71db619ffe44af9178bb22] https://lava.sirena.org.uk/scheduler/job/2044037
> # test job: [380fd29d57abe6679d87ec56babe65ddc5873a37] https://lava.sirena.org.uk/scheduler/job/2044746
> # test job: [af9c8092d84244ca54ffb590435735f788e7a170] https://lava.sirena.org.uk/scheduler/job/2043671
> # test job: [84194c66aaf78fed150edb217b9f341518b1cba2] https://lava.sirena.org.uk/scheduler/job/2038356
> # test job: [252abf2d07d33b1c70a59ba1c9395ba42bbd793e] https://lava.sirena.org.uk/scheduler/job/2038551
> # test job: [2ecc8c089802e033d2e5204d21a9f467e2517df9] https://lava.sirena.org.uk/scheduler/job/2038657
> # test job: [ed5d499b5c9cc11dd3edae1a7a55db7dfa4f1bdc] https://lava.sirena.org.uk/scheduler/job/2029002
> # test job: [e73b743bfe8a6ff4e05b5657d3f7586a17ac3ba0] https://lava.sirena.org.uk/scheduler/job/2026439
> # test job: [f1dfbc1b5cf8650ae9a0d543e5f5335fc0f478ce] https://lava.sirena.org.uk/scheduler/job/2025521
> # test job: [ecd0de438c1f0ee86cf8f6d5047965a2a181444b] https://lava.sirena.org.uk/scheduler/job/2026118
> # test job: [6ef8e042cdcaabe3e3c68592ba8bfbaee2fa10a3] https://lava.sirena.org.uk/scheduler/job/2025847
> # test job: [20bcda681f8597e86070a4b3b12d1e4f541865d3] https://lava.sirena.org.uk/scheduler/job/2022995
> # test job: [cf6bf51b53252284bafc7377a4d8dbf10f048b4d] https://lava.sirena.org.uk/scheduler/job/2023023
> # test job: [28039efa4d8e8bbf98b066133a906bd4e307d496] https://lava.sirena.org.uk/scheduler/job/2020299
> # test job: [e062bdfdd6adbb2dee7751d054c1d8df63ddb8b8] https://lava.sirena.org.uk/scheduler/job/2020172
> # test job: [8fdb030fe283c84fd8d378c97ad0f32d6cdec6ce] https://lava.sirena.org.uk/scheduler/job/2021459
> # test job: [66fecfa91deb536a12ddf3d878a99590d7900277] https://lava.sirena.org.uk/scheduler/job/2015314
> # test job: [f034c16a4663eaf3198dc18b201ba50533fb5b81] https://lava.sirena.org.uk/scheduler/job/2015467
> # test job: [4a5ac6cd05a7e54f1585d7779464d6ed6272c134] https://lava.sirena.org.uk/scheduler/job/2011273
> # test job: [ef042df96d0e1089764f39ede61bc8f140a4be00] https://lava.sirena.org.uk/scheduler/job/2010164
> # test job: [4c33cef58965eb655a0ac8e243aa323581ec025f] https://lava.sirena.org.uk/scheduler/job/2009454
> # test job: [01313661b248c5ba586acae09bff57077dbec0a5] https://lava.sirena.org.uk/scheduler/job/2008766
> # test job: [e7434adf0c53a84d548226304cdb41c8818da1cb] https://lava.sirena.org.uk/scheduler/job/2007795
> # test job: [77a58ba7c64ccca20616aa03599766ccb0d1a330] https://lava.sirena.org.uk/scheduler/job/2007309
> # test job: [4795375d8aa072e9aacb0b278e6203c6ca41816a] https://lava.sirena.org.uk/scheduler/job/2009693
> # test job: [d29479abaded34b2b1dab2e17efe96a65eba3d61] https://lava.sirena.org.uk/scheduler/job/2008426
> # test job: [e973dfe9259095fb509ab12658c68d46f0e439d7] https://lava.sirena.org.uk/scheduler/job/2008132
> # test job: [c17fa4cbc546c431ccf13e9354d5d9c1cd247b7c] https://lava.sirena.org.uk/scheduler/job/2000029
> # test job: [2528c15f314ece50218d1273654f630d74109583] https://lava.sirena.org.uk/scheduler/job/1997624
> # test job: [d054cc3a2ccfb19484f3b54d69b6e416832dc8f4] https://lava.sirena.org.uk/scheduler/job/1995769
> # test job: [310bf433c01f78e0756fd5056a43118a2f77318c] https://lava.sirena.org.uk/scheduler/job/1996063
> # test job: [fd5ef3d69f8975bad16c437a337b5cb04c8217a2] https://lava.sirena.org.uk/scheduler/job/1996144
> # test job: [638bae3fb225a708dc67db613af62f6d14c4eff4] https://lava.sirena.org.uk/scheduler/job/1991895
> # test job: [ecba655bf54a661ffe078856cd8dbc898270e4b5] https://lava.sirena.org.uk/scheduler/job/1985163
> # test job: [7e1906643a7374529af74b013bba35e4fa4e6ffc] https://lava.sirena.org.uk/scheduler/job/1978631
> # test job: [d742ebcfe524dc54023f7c520d2ed2e4b7203c19] https://lava.sirena.org.uk/scheduler/job/1975980
> # test job: [6658472a3e2de08197acfe099ba71ee0e2505ecf] https://lava.sirena.org.uk/scheduler/job/1975543
> # test job: [fce217449075d59b29052b8cdac567f0f3e22641] https://lava.sirena.org.uk/scheduler/job/1975685
> # test job: [0cc08c8130ac8f74419f99fe707dc193b7f79d86] https://lava.sirena.org.uk/scheduler/job/1965718
> # test job: [0743acf746a81e0460a56fd5ff847d97fa7eb370] https://lava.sirena.org.uk/scheduler/job/1964864
> # test job: [d77daa49085b067137d0adbe3263f75a7ee13a1b] https://lava.sirena.org.uk/scheduler/job/1962775
> # test job: [15afe57a874eaf104bfbb61ec598fa31627f7b19] https://lava.sirena.org.uk/scheduler/job/1962957
> # test job: [1e570e77392f43a3cdab2849d1f81535f8a033e2] https://lava.sirena.org.uk/scheduler/job/1962291
> # test job: [fb25114cd760c13cf177d9ac37837fafcc9657b5] https://lava.sirena.org.uk/scheduler/job/1960165
> # test job: [6621b0f118d500092f5f3d72ddddb22aeeb3c3a0] https://lava.sirena.org.uk/scheduler/job/1959743
> # test job: [65efe5404d151767653c7b7dd39bd2e7ad532c2d] https://lava.sirena.org.uk/scheduler/job/1959980
> # test job: [433e294c3c5b5d2020085a0e36c1cb47b694690a] https://lava.sirena.org.uk/scheduler/job/1957437
> # test job: [0b0eb7702a9fa410755e86124b4b7cd36e7d1cb4] https://lava.sirena.org.uk/scheduler/job/1957381
> # test job: [bf770d6d2097a52d87f4d9c88d0b05bd3998d7de] https://lava.sirena.org.uk/scheduler/job/1986562
> # test job: [c2d420796a427dda71a2400909864e7f8e037fd4] https://lava.sirena.org.uk/scheduler/job/1986677
> # test job: [7e7e2c6e2a1cb250f8d03bb99eed01f6d982d5dd] https://lava.sirena.org.uk/scheduler/job/1954262
> # test job: [64d87ccfae3326a9561fe41dc6073064a083e0df] https://lava.sirena.org.uk/scheduler/job/1947255
> # test job: [4d410ba9aa275e7990a270f63ce436990ace1bea] https://lava.sirena.org.uk/scheduler/job/1947749
> # test job: [5e537031f322d55315cd384398b726a9a0748d47] https://lava.sirena.org.uk/scheduler/job/1946642
> # test job: [4412ab501677606436e5c49e41151a1e6eac7ac0] https://lava.sirena.org.uk/scheduler/job/1946288
> # test job: [9797329220a2c6622411eb9ecf6a35b24ce09d04] https://lava.sirena.org.uk/scheduler/job/1947398
> # test job: [fe8cc44dd173cde5788ab4e3730ac61f3d316d9c] https://lava.sirena.org.uk/scheduler/job/1946085
> # test job: [6277a486a7faaa6c87f4bf1d59a2de233a093248] https://lava.sirena.org.uk/scheduler/job/1947023
> # test job: [b83fb1b14c06bdd765903ac852ba20a14e24f227] https://lava.sirena.org.uk/scheduler/job/1946841
> # test job: [fe4d0dea039f2befb93f27569593ec209843b0f5] https://lava.sirena.org.uk/scheduler/job/2106243
> # bad: [fe4d0dea039f2befb93f27569593ec209843b0f5] Add linux-next specific files for 20251119
> git bisect bad fe4d0dea039f2befb93f27569593ec209843b0f5
> # test job: [c8e2262ce3e7658f7689975d66bbdecaf2cf95f9] https://lava.sirena.org.uk/scheduler/job/2106516
> # bad: [c8e2262ce3e7658f7689975d66bbdecaf2cf95f9] Merge branch 'master' of https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git
> git bisect bad c8e2262ce3e7658f7689975d66bbdecaf2cf95f9
> # test job: [2d48532d7f2e7d165f29ca9f2cdd589d9a8c2554] https://lava.sirena.org.uk/scheduler/job/2106588
> # bad: [2d48532d7f2e7d165f29ca9f2cdd589d9a8c2554] Merge branch 'fs-next' of linux-next
> git bisect bad 2d48532d7f2e7d165f29ca9f2cdd589d9a8c2554
> # test job: [f80c4f29e62d88f612101dc7addb0cc7a3bc628d] https://lava.sirena.org.uk/scheduler/job/2106622
> # bad: [f80c4f29e62d88f612101dc7addb0cc7a3bc628d] Merge branch 'next' of https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel.git
> git bisect bad f80c4f29e62d88f612101dc7addb0cc7a3bc628d
> # test job: [b7ea3276cbe7ea3cb272c4f7fc0f38db6ea7f1ed] https://lava.sirena.org.uk/scheduler/job/2106673
> # bad: [b7ea3276cbe7ea3cb272c4f7fc0f38db6ea7f1ed] Merge branch 'at91-next' of https://git.kernel.org/pub/scm/linux/kernel/git/at91/linux.git
> git bisect bad b7ea3276cbe7ea3cb272c4f7fc0f38db6ea7f1ed
> # test job: [e92c9e71a82b75ce8297b60db4693af85ef4593b] https://lava.sirena.org.uk/scheduler/job/2106728
> # bad: [e92c9e71a82b75ce8297b60db4693af85ef4593b] Merge branch 'mm-unstable' of https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> git bisect bad e92c9e71a82b75ce8297b60db4693af85ef4593b
> # test job: [7d808bf13943f4c6a6142400bffe14267f6dc997] https://lava.sirena.org.uk/scheduler/job/2106774
> # good: [7d808bf13943f4c6a6142400bffe14267f6dc997] mm/damon/tests/sysfs-kunit: handle alloc failures on damon_sysfs_test_add_targets()
> git bisect good 7d808bf13943f4c6a6142400bffe14267f6dc997
> # test job: [93f3c3ac6e9a0695dec5ca8c5aa0fdc7ada3293e] https://lava.sirena.org.uk/scheduler/job/2106827
> # bad: [93f3c3ac6e9a0695dec5ca8c5aa0fdc7ada3293e] mm: vmstat: correct the comment above preempt_disable_nested()
> git bisect bad 93f3c3ac6e9a0695dec5ca8c5aa0fdc7ada3293e
> # test job: [16cdd4e5a52b421b27b598b9eee3cd18212944a1] https://lava.sirena.org.uk/scheduler/job/2106960
> # good: [16cdd4e5a52b421b27b598b9eee3cd18212944a1] migrate: optimise alloc_migration_target()
> git bisect good 16cdd4e5a52b421b27b598b9eee3cd18212944a1
> # test job: [3da23b1058cde436f5ab711f4597dbe75865ea38] https://lava.sirena.org.uk/scheduler/job/2107042
> # bad: [3da23b1058cde436f5ab711f4597dbe75865ea38] tools/testing/selftests/mm: add smaps visibility guard region test
> git bisect bad 3da23b1058cde436f5ab711f4597dbe75865ea38
> # test job: [6b82275fdba27802ad7ec6910b86d83bea2dda8d] https://lava.sirena.org.uk/scheduler/job/2107095
> # good: [6b82275fdba27802ad7ec6910b86d83bea2dda8d] mm: add atomic VMA flags and set VM_MAYBE_GUARD as such
> git bisect good 6b82275fdba27802ad7ec6910b86d83bea2dda8d
> # test job: [b331f7745489548c5a020301f6f3b4aad20c7b77] https://lava.sirena.org.uk/scheduler/job/2107146
> # bad: [b331f7745489548c5a020301f6f3b4aad20c7b77] mm: introduce copy-on-fork VMAs and make VM_MAYBE_GUARD one
> git bisect bad b331f7745489548c5a020301f6f3b4aad20c7b77
> # test job: [f24f3801039f9a2033e3a2390fccc5adc00a8df7] https://lava.sirena.org.uk/scheduler/job/2107157
> # good: [f24f3801039f9a2033e3a2390fccc5adc00a8df7] mm: implement sticky VMA flags
> git bisect good f24f3801039f9a2033e3a2390fccc5adc00a8df7
> # test job: [2c91ae77d8fbafb153c13e554f50b7bbeef59d76] https://lava.sirena.org.uk/scheduler/job/2107231
> # bad: [2c91ae77d8fbafb153c13e554f50b7bbeef59d76] mm-implement-sticky-vma-flags-fix-2
> git bisect bad 2c91ae77d8fbafb153c13e554f50b7bbeef59d76
> # test job: [79ee48c12ef8fe9a3daf0dbeda74f038a3f557be] https://lava.sirena.org.uk/scheduler/job/2107257
> # bad: [79ee48c12ef8fe9a3daf0dbeda74f038a3f557be] mm-implement-sticky-vma-flags-fix
> git bisect bad 79ee48c12ef8fe9a3daf0dbeda74f038a3f557be
> # first bad commit: [79ee48c12ef8fe9a3daf0dbeda74f038a3f557be] mm-implement-sticky-vma-flags-fix
^ permalink raw reply
* Re: [PATCH v3 3/8] mm: implement sticky VMA flags
From: Lorenzo Stoakes @ 2025-11-19 13:40 UTC (permalink / raw)
To: Pedro Falcato
Cc: Mark Brown, Andrew Morton, Jonathan Corbet, David Hildenbrand,
Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Steven Rostedt,
Masami Hiramatsu, Mathieu Desnoyers, Jann Horn, Zi Yan,
Baolin Wang, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, linux-kernel, linux-fsdevel, linux-doc, linux-mm,
linux-trace-kernel, linux-kselftest, Andrei Vagin, Aishwarya.TCV
In-Reply-To: <4dodae73i5ganur6llvbbxcojt4uailsxs6sr5w2jr4a7tzxkf@26rmrmcdjvlz>
On Wed, Nov 19, 2025 at 01:27:08PM +0000, Pedro Falcato wrote:
> On Wed, Nov 19, 2025 at 01:16:36PM +0000, Mark Brown wrote:
> > On Fri, Nov 07, 2025 at 04:11:48PM +0000, Lorenzo Stoakes wrote:
> > > It is useful to be able to designate that certain flags are 'sticky', that
> > > is, if two VMAs are merged one with a flag of this nature and one without,
> > > the merged VMA sets this flag.
> >
> > I'm seeing regressions on multiple arm64 platforms in at least the LTP
> > clone302 and madvise10 selftests, both of which have bisected to one of
> > the fixups to this patch. Especially given the other tests that also
> > bisected to the same place I've not investigated further. There's a
> > number of other LTP tests that started failing today including relevant
> > seeming ones munlockall01, mprotect04, madvise10, mprotect03 and
> > futex_cmp_requeue01 but I don't have bisects to confirm they're the same
> > thing.
> >
>
> Thanks for the reports!
>
> > clone302:
> >
> > tst_buffers.c:57: TINFO: Test is using guarded buffers
> > tst_tmpdir.c:316: TINFO: Using /tmp/LTP_clorMwMMw as tmpdir (nfs filesystem)
> > tst_test.c:1953: TINFO: LTP version: 20250530
> > tst_test.c:1956: TINFO: Tested kernel: 6.18.0-rc6-next-20251119 #1 SMP PREEMPT @1763523415 aarch64
>
> next-20251119 still has the v3 version of the patchset, which is Known Bad(tm)
> after a couple of buggy fixups. v4 should hopefully work properly.
>
> --
> Pedro
Thanks for the reports Mark and also for following up Pedro, and yeah this
should now be fully resolved in v4, see [0].
The fixups were just broken but luckily Pedro noticed the mistake I'd made and
so was able to get a fix out quickly! :)
[0]:https://lore.kernel.org/all/cover.1763460113.git.lorenzo.stoakes@oracle.com/
Cheers, Lorenzo
^ permalink raw reply
* Re: [RFC PATCH v7 29/31] x86/mm/pti: Implement a TLB flush immediately after a switch to kernel CR3
From: Andy Lutomirski @ 2025-11-19 14:31 UTC (permalink / raw)
To: Valentin Schneider, Linux Kernel Mailing List, linux-mm, rcu,
the arch/x86 maintainers, linux-arm-kernel, loongarch,
linux-riscv, linux-arch, linux-trace-kernel
Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
H. Peter Anvin, Peter Zijlstra (Intel), Arnaldo Carvalho de Melo,
Josh Poimboeuf, Paolo Bonzini, Arnd Bergmann, Frederic Weisbecker,
Paul E. McKenney, Jason Baron, Steven Rostedt, Ard Biesheuvel,
Sami Tolvanen, David S. Miller, Neeraj Upadhyay, Joel Fernandes,
Josh Triplett, Boqun Feng, Uladzislau Rezki, Mathieu Desnoyers,
Mel Gorman, Andrew Morton, Masahiro Yamada, Han Shen,
Rik van Riel, Jann Horn, Dan Carpenter, Oleg Nesterov, Juri Lelli,
Clark Williams, Yair Podemsky, Marcelo Tosatti, Daniel Wagner,
Petr Tesarik, Shrikanth Hegde
In-Reply-To: <20251114151428.1064524-9-vschneid@redhat.com>
On Fri, Nov 14, 2025, at 7:14 AM, Valentin Schneider wrote:
> Deferring kernel range TLB flushes requires the guarantee that upon
> entering the kernel, no stale entry may be accessed. The simplest way to
> provide such a guarantee is to issue an unconditional flush upon switching
> to the kernel CR3, as this is the pivoting point where such stale entries
> may be accessed.
>
Doing this together with the PTI CR3 switch has no actual benefit: MOV CR3 doesn’t flush global pages. And doing this in asm is pretty gross. We don’t even get a free sync_core() out of it because INVPCID is not documented as being serializing.
Why can’t we do it in C? What’s the actual risk? In order to trip over a stale TLB entry, we would need to deference a pointer to newly allocated kernel virtual memory that was not valid prior to our entry into user mode. I can imagine BPF doing this, but plain noinstr C in the entry path? Especially noinstr C *that has RCU disabled*? We already can’t follow an RCU pointer, and ISTM the only style of kernel code that might do this would use RCU to protect the pointer, and we are already doomed if we follow an RCU pointer to any sort of memory.
We do need to watch out for NMI/MCE hitting before we flush.
^ permalink raw reply
* Re: [PATCH v3 00/21] treewide: Introduce %ptS for struct timespec64 and convert users
From: Andy Shevchenko @ 2025-11-19 14:59 UTC (permalink / raw)
To: Petr Mladek
Cc: Steven Rostedt, linux-doc, linux-kernel, openipmi-developer,
linux-media, dri-devel, linaro-mm-sig, amd-gfx, linux-arm-msm,
freedreno, intel-xe, linux-mmc, netdev, intel-wired-lan,
linux-pci, linux-s390, linux-scsi, linux-staging, ceph-devel,
linux-trace-kernel, Rasmus Villemoes, Sergey Senozhatsky,
Jonathan Corbet
In-Reply-To: <aR3B8ECx9W6F0BV_@pathway.suse.cz>
On Wed, Nov 19, 2025 at 02:11:12PM +0100, Petr Mladek wrote:
> On Thu 2025-11-13 15:32:14, Andy Shevchenko wrote:
> > Here is the third part of the unification time printing in the kernel.
> > This time for struct timespec64. The first patch brings a support
> > into printf() implementation (test cases and documentation update
> > included) followed by the treewide conversion of the current users.
> >
> > Petr, we got like more than a half being Acked, I think if you are okay
> > with this, the patches that have been tagged can be applied.
> >
> > Note, not everything was compile-tested. Kunit test has been passed, though.
>
> JFYI, the patchset has been committed into printk/linux.git,
> branch for-6.19-vsprintf-timespec64.
>
> Note, that I have:
>
> + fixed the 19th patch as proposed, see
> https://lore.kernel.org/all/aR2XAYWTEgMZu_Mx@pathway.suse.cz/
>
> + reviewed all patches but I triple checked 7th patch which
> did not have any ack yet. And I added my Reviewed-by tag
> there. ;-)
>
> + I tried build with allyesconfig. It succeeded. I am not 100%
> sure that it built all modified sources but...
Thank you!
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply
* Re: [PATCH v8 19/28] KVM: arm64: Support unaligned fixmap in the pKVM hyp
From: Marc Zyngier @ 2025-11-19 15:38 UTC (permalink / raw)
To: Vincent Donnefort
Cc: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui, kvmarm,
linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel
In-Reply-To: <20251107093840.3779150-20-vdonnefort@google.com>
On Fri, 07 Nov 2025 09:38:31 +0000,
Vincent Donnefort <vdonnefort@google.com> wrote:
>
> Return the fixmap VA with the page offset, instead of the page base
> address. This allows to use hyp_fixmap_map() seamlessly regardless of
> the address alignment.
>
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
> index ae8391baebc3..75014dc7d82e 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mm.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mm.c
> @@ -239,7 +239,7 @@ static void *fixmap_map_slot(struct hyp_fixmap_slot *slot, phys_addr_t phys)
> WRITE_ONCE(*ptep, pte);
> dsb(ishst);
>
> - return (void *)slot->addr;
> + return (void *)slot->addr + offset_in_page(phys);
> }
>
> void *hyp_fixmap_map(phys_addr_t phys)
This looks slightly odd. fixmap_map_slot() should return *a slot*, not
something in it. Can't hyp_fixmap_map() do that instead?
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply
* Re: [PATCH v8 20/28] KVM: arm64: Add clock support for the pKVM hyp
From: Marc Zyngier @ 2025-11-19 15:44 UTC (permalink / raw)
To: Vincent Donnefort
Cc: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui, kvmarm,
linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel
In-Reply-To: <20251107093840.3779150-21-vdonnefort@google.com>
On Fri, 07 Nov 2025 09:38:32 +0000,
Vincent Donnefort <vdonnefort@google.com> wrote:
>
> By default, the arm64 host kernel is using the arch timer as a source
> for sched_clock. Conveniently, EL2 has access to that same counter,
> allowing to generate clock values that are synchronized.
>
> The clock needs nonetheless to be setup with the same slope values as
> the kernel. Introducing at the same time trace_clock() which is expected
> to be later configured by the hypervisor tracing.
>
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
>
> diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
> index e6be1f5d0967..d46621d936e3 100644
> --- a/arch/arm64/include/asm/kvm_hyp.h
> +++ b/arch/arm64/include/asm/kvm_hyp.h
> @@ -146,5 +146,4 @@ extern u64 kvm_nvhe_sym(id_aa64smfr0_el1_sys_val);
> extern unsigned long kvm_nvhe_sym(__icache_flags);
> extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits);
> extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl);
> -
> #endif /* __ARM64_KVM_HYP_H__ */
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/clock.h b/arch/arm64/kvm/hyp/include/nvhe/clock.h
> new file mode 100644
> index 000000000000..9e152521f345
> --- /dev/null
> +++ b/arch/arm64/kvm/hyp/include/nvhe/clock.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ARM64_KVM_HYP_NVHE_CLOCK_H
> +#define __ARM64_KVM_HYP_NVHE_CLOCK_H
> +#include <linux/types.h>
> +
> +#include <asm/kvm_hyp.h>
> +
> +#ifdef CONFIG_PKVM_TRACING
> +void trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc);
> +u64 trace_clock(void);
> +#else
> +static inline void
> +trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc) { }
> +static inline u64 trace_clock(void) { return 0; }
> +#endif
> +#endif
> diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
> index a244ec25f8c5..f55a9a17d38f 100644
> --- a/arch/arm64/kvm/hyp/nvhe/Makefile
> +++ b/arch/arm64/kvm/hyp/nvhe/Makefile
> @@ -17,7 +17,7 @@ ccflags-y += -fno-stack-protector \
> hostprogs := gen-hyprel
> HOST_EXTRACFLAGS += -I$(objtree)/include
>
> -lib-objs := clear_page.o copy_page.o memcpy.o memset.o
> +lib-objs := clear_page.o copy_page.o memcpy.o memset.o tishift.o
> lib-objs := $(addprefix ../../../lib/, $(lib-objs))
>
> CFLAGS_switch.nvhe.o += -Wno-override-init
> @@ -29,6 +29,7 @@ hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
> ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
> hyp-obj-y += ../../../kernel/smccc-call.o
> hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o
> +hyp-obj-$(CONFIG_PKVM_TRACING) += clock.o
> hyp-obj-y += $(lib-objs)
>
> ##
> diff --git a/arch/arm64/kvm/hyp/nvhe/clock.c b/arch/arm64/kvm/hyp/nvhe/clock.c
> new file mode 100644
> index 000000000000..600a300bece7
> --- /dev/null
> +++ b/arch/arm64/kvm/hyp/nvhe/clock.c
> @@ -0,0 +1,65 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2025 Google LLC
> + * Author: Vincent Donnefort <vdonnefort@google.com>
> + */
> +
> +#include <nvhe/clock.h>
> +
> +#include <asm/arch_timer.h>
> +#include <asm/div64.h>
> +
> +static struct clock_data {
> + struct {
> + u32 mult;
> + u32 shift;
> + u64 epoch_ns;
> + u64 epoch_cyc;
> + u64 cyc_overflow64;
> + } data[2];
> + u64 cur;
> +} trace_clock_data;
> +
> +static u64 __clock_mult_uint128(u64 cyc, u32 mult, u32 shift)
> +{
> + __uint128_t ns = (__uint128_t)cyc * mult;
> +
> + ns >>= shift;
> +
> + return (u64)ns;
> +}
> +
> +/* Does not guarantee no reader on the modified bank. */
> +void trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc)
> +{
> + struct clock_data *clock = &trace_clock_data;
> + u64 bank = clock->cur ^ 1;
> +
> + clock->data[bank].mult = mult;
> + clock->data[bank].shift = shift;
> + clock->data[bank].epoch_ns = epoch_ns;
> + clock->data[bank].epoch_cyc = epoch_cyc;
> + clock->data[bank].cyc_overflow64 = ULONG_MAX / mult;
> +
> + smp_store_release(&clock->cur, bank);
> +}
> +
> +/* Using host provided data. Do not use for anything else than debugging. */
> +u64 trace_clock(void)
> +{
> + struct clock_data *clock = &trace_clock_data;
> + u64 bank = smp_load_acquire(&clock->cur);
> + u64 cyc, ns;
> +
> + cyc = __arch_counter_get_cntpct() - clock->data[bank].epoch_cyc;
I can only imagine that you don't care about the broken systems that
do not have a monotonic counter, and that will happily have their
counter swing back and forth?
Also, you may want to document why you are using the physical counter
instead of the virtual one. I guess that you don't want CNTVOFF_EL2 to
apply when HCR_EL2.E2H==0, but given that you never allow anything
else for pKVM, this is slightly odd.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply
* Re: [RFC PATCH v7 29/31] x86/mm/pti: Implement a TLB flush immediately after a switch to kernel CR3
From: Valentin Schneider @ 2025-11-19 15:44 UTC (permalink / raw)
To: Andy Lutomirski, Linux Kernel Mailing List, linux-mm, rcu,
the arch/x86 maintainers, linux-arm-kernel, loongarch,
linux-riscv, linux-arch, linux-trace-kernel
Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
H. Peter Anvin, Peter Zijlstra (Intel), Arnaldo Carvalho de Melo,
Josh Poimboeuf, Paolo Bonzini, Arnd Bergmann, Frederic Weisbecker,
Paul E. McKenney, Jason Baron, Steven Rostedt, Ard Biesheuvel,
Sami Tolvanen, David S. Miller, Neeraj Upadhyay, Joel Fernandes,
Josh Triplett, Boqun Feng, Uladzislau Rezki, Mathieu Desnoyers,
Mel Gorman, Andrew Morton, Masahiro Yamada, Han Shen,
Rik van Riel, Jann Horn, Dan Carpenter, Oleg Nesterov, Juri Lelli,
Clark Williams, Yair Podemsky, Marcelo Tosatti, Daniel Wagner,
Petr Tesarik, Shrikanth Hegde
In-Reply-To: <65ae9404-5d7d-42a3-969e-7e2ceb56c433@app.fastmail.com>
On 19/11/25 06:31, Andy Lutomirski wrote:
> On Fri, Nov 14, 2025, at 7:14 AM, Valentin Schneider wrote:
>> Deferring kernel range TLB flushes requires the guarantee that upon
>> entering the kernel, no stale entry may be accessed. The simplest way to
>> provide such a guarantee is to issue an unconditional flush upon switching
>> to the kernel CR3, as this is the pivoting point where such stale entries
>> may be accessed.
>>
>
> Doing this together with the PTI CR3 switch has no actual benefit: MOV CR3 doesn’t flush global pages. And doing this in asm is pretty gross. We don’t even get a free sync_core() out of it because INVPCID is not documented as being serializing.
>
> Why can’t we do it in C? What’s the actual risk? In order to trip over a stale TLB entry, we would need to deference a pointer to newly allocated kernel virtual memory that was not valid prior to our entry into user mode. I can imagine BPF doing this, but plain noinstr C in the entry path? Especially noinstr C *that has RCU disabled*? We already can’t follow an RCU pointer, and ISTM the only style of kernel code that might do this would use RCU to protect the pointer, and we are already doomed if we follow an RCU pointer to any sort of memory.
>
So v4 and earlier had the TLB flush faff done in C in the context_tracking entry
just like sync_core().
My biggest issue with it was that I couldn't figure out a way to instrument
memory accesses such that I would get an idea of where vmalloc'd accesses
happen - even with a hackish thing just to survey the landscape. So while I
agree with your reasoning wrt entry noinstr code, I don't have any way to
prove it.
That's unlike the text_poke sync_core() deferral for which I have all of
that nice objtool instrumentation.
Dave also pointed out that the whole stale entry flush deferral is a risky
move, and that the sanest thing would be to execute the deferred flush just
after switching to the kernel CR3.
See the thread surrounding:
https://lore.kernel.org/lkml/20250114175143.81438-30-vschneid@redhat.com/
mainly Dave's reply and subthread:
https://lore.kernel.org/lkml/352317e3-c7dc-43b4-b4cb-9644489318d0@intel.com/
> We do need to watch out for NMI/MCE hitting before we flush.
^ permalink raw reply
* Re: [PATCH v3 15/21] PCI: epf-test: Switch to use %ptSp
From: Manivannan Sadhasivam @ 2025-11-19 15:49 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Corey Minyard, Christian König, Dr. David Alan Gilbert,
Alex Deucher, Thomas Zimmermann, Dmitry Baryshkov, Rob Clark,
Matthew Brost, Ulf Hansson, Aleksandr Loktionov, Vitaly Lifshits,
Niklas Cassel, Calvin Owens, Vadim Fedorenko, Sagi Maimon,
Martin K. Petersen, Karan Tilak Kumar, Hans Verkuil,
Casey Schaufler, Steven Rostedt, Petr Mladek, Viacheslav Dubeyko,
Max Kellermann, linux-doc, linux-kernel, openipmi-developer,
linux-media, dri-devel, linaro-mm-sig, amd-gfx, linux-arm-msm,
freedreno, intel-xe, linux-mmc, netdev, intel-wired-lan,
linux-pci, linux-s390, linux-scsi, linux-staging, ceph-devel,
linux-trace-kernel, Rasmus Villemoes, Sergey Senozhatsky,
Jonathan Corbet, Sumit Semwal, Gustavo Padovan, David Airlie,
Simona Vetter, Maarten Lankhorst, Maxime Ripard, Dmitry Baryshkov,
Abhinav Kumar, Jessica Zhang, Sean Paul, Marijn Suijten,
Konrad Dybcio, Lucas De Marchi, Thomas Hellström,
Rodrigo Vivi, Vladimir Oltean, Andrew Lunn, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Tony Nguyen,
Przemek Kitszel, Krzysztof Wilczyński,
Kishon Vijay Abraham I, Bjorn Helgaas, Rodolfo Giometti,
Jonathan Lemon, Richard Cochran, Stefan Haberland, Jan Hoeppner,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Satish Kharat,
Sesidhar Baddela, James E.J. Bottomley, Mauro Carvalho Chehab,
Greg Kroah-Hartman, Xiubo Li, Ilya Dryomov, Masami Hiramatsu,
Mathieu Desnoyers, Andrew Morton
In-Reply-To: <20251113150217.3030010-16-andriy.shevchenko@linux.intel.com>
On Thu, Nov 13, 2025 at 03:32:29PM +0100, Andy Shevchenko wrote:
> Use %ptSp instead of open coded variants to print content of
> struct timespec64 in human readable format.
>
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
- Mani
> ---
> drivers/pci/endpoint/functions/pci-epf-test.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index b05e8db575c3..debd235253c5 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -331,9 +331,8 @@ static void pci_epf_test_print_rate(struct pci_epf_test *epf_test,
> rate = div64_u64(size * NSEC_PER_SEC, ns * 1000);
>
> dev_info(&epf_test->epf->dev,
> - "%s => Size: %llu B, DMA: %s, Time: %llu.%09u s, Rate: %llu KB/s\n",
> - op, size, dma ? "YES" : "NO",
> - (u64)ts.tv_sec, (u32)ts.tv_nsec, rate);
> + "%s => Size: %llu B, DMA: %s, Time: %ptSp s, Rate: %llu KB/s\n",
> + op, size, dma ? "YES" : "NO", &ts, rate);
> }
>
> static void pci_epf_test_copy(struct pci_epf_test *epf_test,
> --
> 2.50.1
>
--
மணிவண்ணன் சதாசிவம்
^ permalink raw reply
* Re: [PATCH v4 3/9] mm: update vma_modify_flags() to handle residual flags, document
From: Vlastimil Babka @ 2025-11-19 16:27 UTC (permalink / raw)
To: Lorenzo Stoakes, Andrew Morton
Cc: Jonathan Corbet, David Hildenbrand, Liam R . Howlett,
Mike Rapoport, Suren Baghdasaryan, Michal Hocko, Steven Rostedt,
Masami Hiramatsu, Mathieu Desnoyers, Jann Horn, Pedro Falcato,
Zi Yan, Baolin Wang, Nico Pache, Ryan Roberts, Dev Jain,
Barry Song, Lance Yang, linux-kernel, linux-fsdevel, linux-doc,
linux-mm, linux-trace-kernel, linux-kselftest, Andrei Vagin
In-Reply-To: <23b5b549b0eaefb2922625626e58c2a352f3e93c.1763460113.git.lorenzo.stoakes@oracle.com>
On 11/18/25 11:17, Lorenzo Stoakes wrote:
> The vma_modify_*() family of functions each either perform splits, a merge
> or no changes at all in preparation for the requested modification to
> occur.
>
> When doing so for a VMA flags change, we currently don't account for any
> flags which may remain (for instance, VM_SOFTDIRTY) despite the requested
> change in the case that a merge succeeded.
>
> This is made more important by subsequent patches which will introduce the
> concept of sticky VMA flags which rely on this behaviour.
>
> This patch fixes this by passing the VMA flags parameter as a pointer and
> updating it accordingly on merge and updating callers to accommodate for
> this.
>
> Additionally, while we are here, we add kdocs for each of the
> vma_modify_*() functions, as the fact that the requested modification is
> not performed is confusing so it is useful to make this abundantly
> clear.
>
> We also update the VMA userland tests to account for this change.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
LGTM (where the "good" means "correct" (*), not "nice", which is however not
a fault of the patch but the pre-existing code :)
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
(*) but it's likely there will be a fix needed, whenever I conclude this
^ permalink raw reply
* Re: [PATCH v4 3/9] mm: update vma_modify_flags() to handle residual flags, document
From: Pedro Falcato @ 2025-11-19 16:36 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Andrew Morton, Jonathan Corbet, David Hildenbrand,
Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Steven Rostedt,
Masami Hiramatsu, Mathieu Desnoyers, Jann Horn, Zi Yan,
Baolin Wang, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, linux-kernel, linux-fsdevel, linux-doc, linux-mm,
linux-trace-kernel, linux-kselftest, Andrei Vagin
In-Reply-To: <23b5b549b0eaefb2922625626e58c2a352f3e93c.1763460113.git.lorenzo.stoakes@oracle.com>
On Tue, Nov 18, 2025 at 10:17:45AM +0000, Lorenzo Stoakes wrote:
> The vma_modify_*() family of functions each either perform splits, a merge
> or no changes at all in preparation for the requested modification to
> occur.
>
> When doing so for a VMA flags change, we currently don't account for any
> flags which may remain (for instance, VM_SOFTDIRTY) despite the requested
> change in the case that a merge succeeded.
>
> This is made more important by subsequent patches which will introduce the
> concept of sticky VMA flags which rely on this behaviour.
>
> This patch fixes this by passing the VMA flags parameter as a pointer and
> updating it accordingly on merge and updating callers to accommodate for
> this.
>
> Additionally, while we are here, we add kdocs for each of the
> vma_modify_*() functions, as the fact that the requested modification is
> not performed is confusing so it is useful to make this abundantly
> clear.
>
> We also update the VMA userland tests to account for this change.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Quite ugly change, but for the sake of brevity I think we can live it
Temporarily(tm).
--
Pedro
^ permalink raw reply
* Re: [PATCH v4 2/5] perf tools: Minimal DEFERRED_CALLCHAIN support
From: Ian Rogers @ 2025-11-19 16:48 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, James Clark, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users,
Steven Rostedt, Josh Poimboeuf, Indu Bhagat, Jens Remus,
Mathieu Desnoyers, linux-trace-kernel, bpf
In-Reply-To: <20251115234106.348571-3-namhyung@kernel.org>
On Sat, Nov 15, 2025 at 3:41 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Add a new event type for deferred callchains and a new callback for the
> struct perf_tool. For now it doesn't actually handle the deferred
> callchains but it just marks the sample if it has the PERF_CONTEXT_
> USER_DEFFERED in the callchain array.
>
> At least, perf report can dump the raw data with this change. Actually
> this requires the next commit to enable attr.defer_callchain, but if you
> already have a data file, it'll show the following result.
>
> $ perf report -D
> ...
> 0x2158@perf.data [0x40]: event: 22
> .
> . ... raw event: size 64 bytes
> . 0000: 16 00 00 00 02 00 40 00 06 00 00 00 0b 00 00 00 ......@.........
> . 0010: 03 00 00 00 00 00 00 00 a7 7f 33 fe 18 7f 00 00 ..........3.....
> . 0020: 0f 0e 33 fe 18 7f 00 00 48 14 33 fe 18 7f 00 00 ..3.....H.3.....
> . 0030: 08 09 00 00 08 09 00 00 e6 7a e7 35 1c 00 00 00 .........z.5....
>
> 121163447014 0x2158 [0x40]: PERF_RECORD_CALLCHAIN_DEFERRED(IP, 0x2): 2312/2312: 0xb00000006
> ... FP chain: nr:3
> ..... 0: 00007f18fe337fa7
> ..... 1: 00007f18fe330e0f
> ..... 2: 00007f18fe331448
> : unhandled!
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/lib/perf/include/perf/event.h | 13 ++++++++++
> tools/perf/util/event.c | 1 +
> tools/perf/util/evsel.c | 31 +++++++++++++++++++++--
> tools/perf/util/machine.c | 1 +
> tools/perf/util/perf_event_attr_fprintf.c | 2 ++
> tools/perf/util/sample.h | 2 ++
> tools/perf/util/session.c | 20 +++++++++++++++
> tools/perf/util/tool.c | 1 +
> tools/perf/util/tool.h | 3 ++-
> 9 files changed, 71 insertions(+), 3 deletions(-)
>
> diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
> index aa1e91c97a226e1a..43a8cb04994fa033 100644
> --- a/tools/lib/perf/include/perf/event.h
> +++ b/tools/lib/perf/include/perf/event.h
> @@ -151,6 +151,18 @@ struct perf_record_switch {
> __u32 next_prev_tid;
> };
>
> +struct perf_record_callchain_deferred {
> + struct perf_event_header header;
> + /*
> + * This is to match kernel and (deferred) user stacks together.
> + * The kernel part will be in the sample callchain array after
> + * the PERF_CONTEXT_USER_DEFERRED entry.
> + */
> + __u64 cookie;
> + __u64 nr;
> + __u64 ips[];
> +};
> +
> struct perf_record_header_attr {
> struct perf_event_header header;
> struct perf_event_attr attr;
> @@ -523,6 +535,7 @@ union perf_event {
> struct perf_record_read read;
> struct perf_record_throttle throttle;
> struct perf_record_sample sample;
> + struct perf_record_callchain_deferred callchain_deferred;
> struct perf_record_bpf_event bpf;
> struct perf_record_ksymbol ksymbol;
> struct perf_record_text_poke_event text_poke;
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index fcf44149feb20c35..4c92cc1a952c1d9f 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -61,6 +61,7 @@ static const char *perf_event__names[] = {
> [PERF_RECORD_CGROUP] = "CGROUP",
> [PERF_RECORD_TEXT_POKE] = "TEXT_POKE",
> [PERF_RECORD_AUX_OUTPUT_HW_ID] = "AUX_OUTPUT_HW_ID",
> + [PERF_RECORD_CALLCHAIN_DEFERRED] = "CALLCHAIN_DEFERRED",
> [PERF_RECORD_HEADER_ATTR] = "ATTR",
> [PERF_RECORD_HEADER_EVENT_TYPE] = "EVENT_TYPE",
> [PERF_RECORD_HEADER_TRACING_DATA] = "TRACING_DATA",
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 989c56d4a23f74f4..5ee3e7dee93fbbcb 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -3089,6 +3089,20 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
> data->data_src = PERF_MEM_DATA_SRC_NONE;
> data->vcpu = -1;
>
> + if (event->header.type == PERF_RECORD_CALLCHAIN_DEFERRED) {
> + const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);
> +
> + data->callchain = (struct ip_callchain *)&event->callchain_deferred.nr;
> + if (data->callchain->nr > max_callchain_nr)
> + return -EFAULT;
> +
> + data->deferred_cookie = event->callchain_deferred.cookie;
> +
> + if (evsel->core.attr.sample_id_all)
> + perf_evsel__parse_id_sample(evsel, event, data);
> + return 0;
> + }
> +
> if (event->header.type != PERF_RECORD_SAMPLE) {
> if (!evsel->core.attr.sample_id_all)
> return 0;
> @@ -3213,12 +3227,25 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
>
> if (type & PERF_SAMPLE_CALLCHAIN) {
> const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);
> + u64 callchain_nr;
>
> OVERFLOW_CHECK_u64(array);
> data->callchain = (struct ip_callchain *)array++;
> - if (data->callchain->nr > max_callchain_nr)
> + callchain_nr = data->callchain->nr;
> + if (callchain_nr > max_callchain_nr)
> return -EFAULT;
> - sz = data->callchain->nr * sizeof(u64);
> + sz = callchain_nr * sizeof(u64);
> + /*
> + * Save the cookie for the deferred user callchain. The last 2
> + * entries in the callchain should be the context marker and the
> + * cookie. The cookie will be used to match PERF_RECORD_
> + * CALLCHAIN_DEFERRED later.
> + */
> + if (evsel->core.attr.defer_callchain && callchain_nr >= 2 &&
> + data->callchain->ips[callchain_nr - 2] == PERF_CONTEXT_USER_DEFERRED) {
> + data->deferred_cookie = data->callchain->ips[callchain_nr - 1];
> + data->deferred_callchain = true;
> + }
> OVERFLOW_CHECK(array, sz, max_size);
> array = (void *)array + sz;
> }
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index b5dd42588c916d91..841b711d970e9457 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -2124,6 +2124,7 @@ static int add_callchain_ip(struct thread *thread,
> *cpumode = PERF_RECORD_MISC_KERNEL;
> break;
> case PERF_CONTEXT_USER:
> + case PERF_CONTEXT_USER_DEFERRED:
> *cpumode = PERF_RECORD_MISC_USER;
> break;
> default:
> diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
> index 66b666d9ce649dd7..741c3d657a8b6ae7 100644
> --- a/tools/perf/util/perf_event_attr_fprintf.c
> +++ b/tools/perf/util/perf_event_attr_fprintf.c
> @@ -343,6 +343,8 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
> PRINT_ATTRf(inherit_thread, p_unsigned);
> PRINT_ATTRf(remove_on_exec, p_unsigned);
> PRINT_ATTRf(sigtrap, p_unsigned);
> + PRINT_ATTRf(defer_callchain, p_unsigned);
> + PRINT_ATTRf(defer_output, p_unsigned);
>
> PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned, false);
> PRINT_ATTRf(bp_type, p_unsigned);
> diff --git a/tools/perf/util/sample.h b/tools/perf/util/sample.h
> index fae834144ef42105..a8307b20a9ea8066 100644
> --- a/tools/perf/util/sample.h
> +++ b/tools/perf/util/sample.h
> @@ -107,6 +107,8 @@ struct perf_sample {
> /** @weight3: On x86 holds retire_lat, on powerpc holds p_stage_cyc. */
> u16 weight3;
> bool no_hw_idx; /* No hw_idx collected in branch_stack */
> + bool deferred_callchain; /* Has deferred user callchains */
> + u64 deferred_cookie;
> char insn[MAX_INSN];
> void *raw_data;
> struct ip_callchain *callchain;
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 4b0236b2df2913e1..361e15c1f26a96d0 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -720,6 +720,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
> [PERF_RECORD_CGROUP] = perf_event__cgroup_swap,
> [PERF_RECORD_TEXT_POKE] = perf_event__text_poke_swap,
> [PERF_RECORD_AUX_OUTPUT_HW_ID] = perf_event__all64_swap,
> + [PERF_RECORD_CALLCHAIN_DEFERRED] = perf_event__all64_swap,
> [PERF_RECORD_HEADER_ATTR] = perf_event__hdr_attr_swap,
> [PERF_RECORD_HEADER_EVENT_TYPE] = perf_event__event_type_swap,
> [PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
> @@ -854,6 +855,9 @@ static void callchain__printf(struct evsel *evsel,
> for (i = 0; i < callchain->nr; i++)
> printf("..... %2d: %016" PRIx64 "\n",
> i, callchain->ips[i]);
> +
> + if (sample->deferred_callchain)
> + printf("...... (deferred)\n");
> }
>
> static void branch_stack__printf(struct perf_sample *sample,
> @@ -1123,6 +1127,19 @@ static void dump_sample(struct evsel *evsel, union perf_event *event,
> sample_read__printf(sample, evsel->core.attr.read_format);
> }
>
> +static void dump_deferred_callchain(struct evsel *evsel, union perf_event *event,
> + struct perf_sample *sample)
> +{
> + if (!dump_trace)
> + return;
> +
> + printf("(IP, 0x%x): %d/%d: %#" PRIx64 "\n",
> + event->header.misc, sample->pid, sample->tid, sample->deferred_cookie);
> +
> + if (evsel__has_callchain(evsel))
> + callchain__printf(evsel, sample);
> +}
> +
> static void dump_read(struct evsel *evsel, union perf_event *event)
> {
> struct perf_record_read *read_event = &event->read;
> @@ -1353,6 +1370,9 @@ static int machines__deliver_event(struct machines *machines,
> return tool->text_poke(tool, event, sample, machine);
> case PERF_RECORD_AUX_OUTPUT_HW_ID:
> return tool->aux_output_hw_id(tool, event, sample, machine);
> + case PERF_RECORD_CALLCHAIN_DEFERRED:
> + dump_deferred_callchain(evsel, event, sample);
> + return tool->callchain_deferred(tool, event, sample, evsel, machine);
> default:
> ++evlist->stats.nr_unknown_events;
> return -1;
> diff --git a/tools/perf/util/tool.c b/tools/perf/util/tool.c
> index 22a8a4ffe05f778e..f732d33e7f895ed4 100644
> --- a/tools/perf/util/tool.c
> +++ b/tools/perf/util/tool.c
> @@ -287,6 +287,7 @@ void perf_tool__init(struct perf_tool *tool, bool ordered_events)
> tool->read = process_event_sample_stub;
> tool->throttle = process_event_stub;
> tool->unthrottle = process_event_stub;
> + tool->callchain_deferred = process_event_sample_stub;
nit: there's a similar change needed to delegate_tool__init, that code
is currently unused.
Reviewed-by: Ian Rogers <irogers@google.com>
Thanks,
Ian
> tool->attr = process_event_synth_attr_stub;
> tool->event_update = process_event_synth_event_update_stub;
> tool->tracing_data = process_event_synth_tracing_data_stub;
> diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
> index 88337cee1e3e2be3..9b9f0a8cbf3de4b5 100644
> --- a/tools/perf/util/tool.h
> +++ b/tools/perf/util/tool.h
> @@ -44,7 +44,8 @@ enum show_feature_header {
>
> struct perf_tool {
> event_sample sample,
> - read;
> + read,
> + callchain_deferred;
> event_op mmap,
> mmap2,
> comm,
> --
> 2.52.0.rc1.455.g30608eb744-goog
>
^ permalink raw reply
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