* [PATCH v4 26/63] objtool: Remove .parainstructions reference
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
The .parainstructions section no longer exists since the following
commit:
60bc276b129e ("x86/paravirt: Switch mixed paravirt/alternative calls to alternatives").
Remove the reference to it.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/check.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 48b90836ed4a5..253d52205616a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4477,7 +4477,6 @@ static int validate_ibt(struct objtool_file *file)
!strcmp(sec->name, ".altinstructions") ||
!strcmp(sec->name, ".ibt_endbr_seal") ||
!strcmp(sec->name, ".orc_unwind_ip") ||
- !strcmp(sec->name, ".parainstructions") ||
!strcmp(sec->name, ".retpoline_sites") ||
!strcmp(sec->name, ".smp_locks") ||
!strcmp(sec->name, ".static_call_sites") ||
--
2.50.0
^ permalink raw reply related
* [PATCH v4 25/63] objtool: Clean up compiler flag usage
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
KBUILD_HOSTCFLAGS and KBUILD_HOSTLDFLAGS aren't defined when objtool is
built standalone. Also, the EXTRA_WARNINGS flags are rather arbitrary.
Make things simpler and more consistent by specifying compiler flags
explicitly and tweaking the warnings. Also make a few code tweaks to
make the new warnings happy.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/Makefile | 15 ++++++++++-----
tools/objtool/check.c | 4 ++--
tools/objtool/elf.c | 2 +-
3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 8c20361dd100e..fc82d47f2b9a7 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -23,6 +23,11 @@ LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lel
all: $(OBJTOOL)
+WARNINGS := -Werror -Wall -Wextra -Wmissing-prototypes \
+ -Wmissing-declarations -Wwrite-strings \
+ -Wno-implicit-fallthrough -Wno-sign-compare \
+ -Wno-unused-parameter
+
INCLUDES := -I$(srctree)/tools/include \
-I$(srctree)/tools/include/uapi \
-I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
@@ -30,11 +35,11 @@ INCLUDES := -I$(srctree)/tools/include \
-I$(srctree)/tools/objtool/include \
-I$(srctree)/tools/objtool/arch/$(SRCARCH)/include \
-I$(LIBSUBCMD_OUTPUT)/include
-# Note, EXTRA_WARNINGS here was determined for CC and not HOSTCC, it
-# is passed here to match a legacy behavior.
-WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed -Wno-nested-externs
-OBJTOOL_CFLAGS := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
-OBJTOOL_LDFLAGS := $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
+
+OBJTOOL_CFLAGS := -std=gnu11 -fomit-frame-pointer -O2 -g \
+ $(WARNINGS) $(INCLUDES) $(LIBELF_FLAGS) $(HOSTCFLAGS)
+
+OBJTOOL_LDFLAGS := $(LIBSUBCMD) $(LIBELF_LIBS) $(HOSTLDFLAGS)
# Allow old libelf to be used:
elfshdr := $(shell echo '$(pound)include <libelf.h>' | $(HOSTCC) $(OBJTOOL_CFLAGS) -x c -E - 2>/dev/null | grep elf_getshdr)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index fdb83a0a592a3..48b90836ed4a5 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -461,7 +461,7 @@ static int decode_instructions(struct objtool_file *file)
for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) {
if (!insns || idx == INSN_CHUNK_MAX) {
- insns = calloc(sizeof(*insn), INSN_CHUNK_SIZE);
+ insns = calloc(INSN_CHUNK_SIZE, sizeof(*insn));
if (!insns) {
ERROR_GLIBC("calloc");
return -1;
@@ -607,7 +607,7 @@ static int init_pv_ops(struct objtool_file *file)
return 0;
nr = sym->len / sizeof(unsigned long);
- file->pv_ops = calloc(sizeof(struct pv_state), nr);
+ file->pv_ops = calloc(nr, sizeof(struct pv_state));
if (!file->pv_ops) {
ERROR_GLIBC("calloc");
return -1;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 2ea6d591c3c29..c27edeed2dd03 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -736,7 +736,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab,
}
/* setup extended section index magic and write the symbol */
- if ((shndx >= SHN_UNDEF && shndx < SHN_LORESERVE) || is_special_shndx) {
+ if (shndx < SHN_LORESERVE || is_special_shndx) {
sym->sym.st_shndx = shndx;
if (!shndx_data)
shndx = 0;
--
2.50.0
^ permalink raw reply related
* [PATCH v4 24/63] objtool: Const string cleanup
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Use 'const char *' where applicable.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/arch/loongarch/decode.c | 2 +-
tools/objtool/arch/powerpc/decode.c | 2 +-
tools/objtool/arch/x86/decode.c | 2 +-
tools/objtool/elf.c | 6 +++---
tools/objtool/include/objtool/arch.h | 2 +-
tools/objtool/include/objtool/elf.h | 6 +++---
6 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
index 330671d88c590..7b38718d782a7 100644
--- a/tools/objtool/arch/loongarch/decode.c
+++ b/tools/objtool/arch/loongarch/decode.c
@@ -7,7 +7,7 @@
#include <linux/objtool_types.h>
#include <arch/elf.h>
-int arch_ftrace_match(char *name)
+int arch_ftrace_match(const char *name)
{
return !strcmp(name, "_mcount");
}
diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
index 9b17885e6cba6..d4cb02120a6bd 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -9,7 +9,7 @@
#include <objtool/builtin.h>
#include <objtool/endianness.h>
-int arch_ftrace_match(char *name)
+int arch_ftrace_match(const char *name)
{
return !strcmp(name, "_mcount");
}
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index b10200cc50c99..6bb46d9981533 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -23,7 +23,7 @@
#include <objtool/builtin.h>
#include <arch/elf.h>
-int arch_ftrace_match(char *name)
+int arch_ftrace_match(const char *name)
{
return !strcmp(name, "__fentry__");
}
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index d7fb3d0b05cf1..2ea6d591c3c29 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -853,7 +853,7 @@ elf_create_section_symbol(struct elf *elf, struct section *sec)
return sym;
}
-static int elf_add_string(struct elf *elf, struct section *strtab, char *str);
+static int elf_add_string(struct elf *elf, struct section *strtab, const char *str);
struct symbol *
elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size)
@@ -1086,7 +1086,7 @@ struct elf *elf_open_read(const char *name, int flags)
return NULL;
}
-static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
+static int elf_add_string(struct elf *elf, struct section *strtab, const char *str)
{
Elf_Data *data;
Elf_Scn *s;
@@ -1111,7 +1111,7 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
return -1;
}
- data->d_buf = str;
+ data->d_buf = strdup(str);
data->d_size = strlen(str) + 1;
data->d_align = 1;
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index 68664625a4671..a4502947307a4 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -71,7 +71,7 @@ struct stack_op {
struct instruction;
-int arch_ftrace_match(char *name);
+int arch_ftrace_match(const char *name);
void arch_initial_func_cfi_state(struct cfi_init_state *state);
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index df8434d3b7440..74ce454790f4d 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -40,7 +40,7 @@ struct section {
struct section *base, *rsec;
struct symbol *sym;
Elf_Data *data;
- char *name;
+ const char *name;
int idx;
bool _changed, text, rodata, noinstr, init, truncate;
struct reloc *relocs;
@@ -53,7 +53,7 @@ struct symbol {
struct elf_hash_node name_hash;
GElf_Sym sym;
struct section *sec;
- char *name;
+ const char *name;
unsigned int idx, len;
unsigned long offset;
unsigned long __subtree_last;
@@ -88,7 +88,7 @@ struct elf {
GElf_Ehdr ehdr;
int fd;
bool changed;
- char *name;
+ const char *name;
unsigned int num_files;
struct list_head sections;
unsigned long num_relocs;
--
2.50.0
^ permalink raw reply related
* [PATCH v4 23/63] objtool: Check for missing annotation entries in read_annotate()
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Add a sanity check to make sure none of the relocations for the
.discard.annotate_insn section have gone missing.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/check.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index bea9b124dcf48..fdb83a0a592a3 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2293,6 +2293,11 @@ static int read_annotate(struct objtool_file *file,
sec->sh.sh_entsize = 8;
}
+ if (sec_num_entries(sec) != sec_num_entries(sec->rsec)) {
+ ERROR("bad .discard.annotate_insn section: missing relocs");
+ return -1;
+ }
+
for_each_reloc(sec->rsec, reloc) {
type = *(u32 *)(sec->data->d_buf + (reloc_idx(reloc) * sec->sh.sh_entsize) + 4);
type = bswap_if_needed(file->elf, type);
--
2.50.0
^ permalink raw reply related
* [PATCH v4 22/63] objtool: Fix "unexpected end of section" warning for alternatives
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Due to the short circuiting logic in next_insn_to_validate(), control
flow may silently transition from .altinstr_replacement to .text without
a corresponding nested call to validate_branch().
As a result the validate_branch() 'sec' variable doesn't get
reinitialized, which can trigger a confusing "unexpected end of section"
warning which blames .altinstr_replacement rather than the offending
fallthrough function.
Fix that by not caching the section. There's no point in doing that
anyway.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/check.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 1165dd1669f0b..bea9b124dcf48 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3521,15 +3521,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
{
struct alternative *alt;
struct instruction *next_insn, *prev_insn = NULL;
- struct section *sec;
u8 visited;
int ret;
if (func && func->ignore)
return 0;
- sec = insn->sec;
-
while (1) {
next_insn = next_insn_to_validate(file, insn);
@@ -3769,7 +3766,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
WARN("%s%sunexpected end of section %s",
func ? func->name : "", func ? "(): " : "",
- sec->name);
+ insn->sec->name);
return 1;
}
--
2.50.0
^ permalink raw reply related
* [PATCH v4 21/63] objtool: Fix __pa_symbol() relocation handling
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
__pa_symbol() generates a relocation which refers to a physical address.
Convert it to back its virtual form before calculating the addend.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/arch/x86/decode.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 6742002a01f55..b10200cc50c99 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -68,6 +68,17 @@ bool arch_callee_saved_reg(unsigned char reg)
}
}
+/* Undo the effects of __pa_symbol() if necessary */
+static unsigned long phys_to_virt(unsigned long pa)
+{
+ s64 va = pa;
+
+ if (va > 0)
+ va &= ~(0x80000000);
+
+ return va;
+}
+
s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
{
s64 addend = reloc_addend(reloc);
@@ -75,7 +86,7 @@ s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
if (arch_pc_relative_reloc(reloc))
addend += insn->offset + insn->len - reloc_offset(reloc);
- return addend;
+ return phys_to_virt(addend);
}
unsigned long arch_jump_destination(struct instruction *insn)
--
2.50.0
^ permalink raw reply related
* [PATCH v4 20/63] objtool: Fix x86 addend calculation
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
On x86, arch_dest_reloc_offset() hardcodes the addend adjustment to
four, but the actual adjustment depends on the relocation type. Fix
that.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/arch/loongarch/decode.c | 4 ++--
tools/objtool/arch/powerpc/decode.c | 4 ++--
tools/objtool/arch/x86/decode.c | 9 +++++++--
tools/objtool/check.c | 15 +++++----------
tools/objtool/include/objtool/arch.h | 2 +-
5 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
index b6fdc68053cc4..330671d88c590 100644
--- a/tools/objtool/arch/loongarch/decode.c
+++ b/tools/objtool/arch/loongarch/decode.c
@@ -17,9 +17,9 @@ unsigned long arch_jump_destination(struct instruction *insn)
return insn->offset + (insn->immediate << 2);
}
-unsigned long arch_dest_reloc_offset(int addend)
+s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
{
- return addend;
+ return reloc_addend(reloc);
}
bool arch_pc_relative_reloc(struct reloc *reloc)
diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
index c851c51d4bd35..9b17885e6cba6 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -14,9 +14,9 @@ int arch_ftrace_match(char *name)
return !strcmp(name, "_mcount");
}
-unsigned long arch_dest_reloc_offset(int addend)
+s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
{
- return addend;
+ return reloc_addend(reloc);
}
bool arch_callee_saved_reg(unsigned char reg)
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 0ad5cc70ecbe7..6742002a01f55 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -68,9 +68,14 @@ bool arch_callee_saved_reg(unsigned char reg)
}
}
-unsigned long arch_dest_reloc_offset(int addend)
+s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
{
- return addend + 4;
+ s64 addend = reloc_addend(reloc);
+
+ if (arch_pc_relative_reloc(reloc))
+ addend += insn->offset + insn->len - reloc_offset(reloc);
+
+ return addend;
}
unsigned long arch_jump_destination(struct instruction *insn)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index dbdbbddd01ecb..1165dd1669f0b 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1499,7 +1499,7 @@ static int add_jump_destinations(struct objtool_file *file)
dest_off = arch_jump_destination(insn);
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
- dest_off = arch_dest_reloc_offset(reloc_addend(reloc));
+ dest_off = arch_insn_adjusted_addend(insn, reloc);
} else if (reloc->sym->retpoline_thunk) {
if (add_retpoline_call(file, insn))
return -1;
@@ -1518,7 +1518,7 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
- arch_dest_reloc_offset(reloc_addend(reloc));
+ arch_insn_adjusted_addend(insn, reloc);
} else {
/* non-func asm code jumping to another file */
continue;
@@ -1663,7 +1663,7 @@ static int add_call_destinations(struct objtool_file *file)
}
} else if (reloc->sym->type == STT_SECTION) {
- dest_off = arch_dest_reloc_offset(reloc_addend(reloc));
+ dest_off = arch_insn_adjusted_addend(insn, reloc);
dest = find_call_destination(reloc->sym->sec, dest_off);
if (!dest) {
ERROR_INSN(insn, "can't find call dest symbol at %s+0x%lx",
@@ -3324,7 +3324,7 @@ static bool pv_call_dest(struct objtool_file *file, struct instruction *insn)
if (!reloc || strcmp(reloc->sym->name, "pv_ops"))
return false;
- idx = (arch_dest_reloc_offset(reloc_addend(reloc)) / sizeof(void *));
+ idx = arch_insn_adjusted_addend(insn, reloc) / sizeof(void *);
if (file->pv_ops[idx].clean)
return true;
@@ -4405,12 +4405,7 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
reloc_offset(reloc) + 1,
(insn->offset + insn->len) - (reloc_offset(reloc) + 1))) {
- off = reloc->sym->offset;
- if (reloc_type(reloc) == R_X86_64_PC32 ||
- reloc_type(reloc) == R_X86_64_PLT32)
- off += arch_dest_reloc_offset(reloc_addend(reloc));
- else
- off += reloc_addend(reloc);
+ off = reloc->sym->offset + arch_insn_adjusted_addend(insn, reloc);
dest = find_insn(file, reloc->sym->sec, off);
if (!dest)
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index be33c7b43180a..68664625a4671 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -83,7 +83,7 @@ bool arch_callee_saved_reg(unsigned char reg);
unsigned long arch_jump_destination(struct instruction *insn);
-unsigned long arch_dest_reloc_offset(int addend);
+s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc);
const char *arch_nop_insn(int len);
const char *arch_ret_insn(int len);
--
2.50.0
^ permalink raw reply related
* [PATCH v4 19/63] objtool: Fix weak symbol detection
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
find_symbol_hole_containing() fails to find a symbol hole (aka stripped
weak symbol) if its section has no symbols before the hole. This breaks
weak symbol detection if -ffunction-sections is enabled.
Fix that by allowing the interval tree to contain section symbols, which
are always at offset zero for a given section.
Fixes a bunch of (-ffunction-sections) warnings like:
vmlinux.o: warning: objtool: .text.__x64_sys_io_setup+0x10: unreachable instruction
Fixes: 4adb23686795 ("objtool: Ignore extra-symbol code")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/elf.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index c024937eb12a2..d7fb3d0b05cf1 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -109,7 +109,7 @@ struct symbol_hole {
};
/*
- * Find !section symbol where @offset is after it.
+ * Find the last symbol before @offset.
*/
static int symbol_hole_by_offset(const void *key, const struct rb_node *node)
{
@@ -120,8 +120,7 @@ static int symbol_hole_by_offset(const void *key, const struct rb_node *node)
return -1;
if (sh->key >= s->offset + s->len) {
- if (s->type != STT_SECTION)
- sh->sym = s;
+ sh->sym = s;
return 1;
}
@@ -428,7 +427,8 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym)
sym->len = sym->sym.st_size;
__sym_for_each(iter, &sym->sec->symbol_tree, sym->offset, sym->offset) {
- if (iter->offset == sym->offset && iter->type == sym->type)
+ if (iter->offset == sym->offset && iter->type == sym->type &&
+ iter->len == sym->len)
iter->alias = sym;
}
--
2.50.0
^ permalink raw reply related
* [PATCH v4 18/63] objtool: Fix interval tree insertion for zero-length symbols
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Zero-length symbols get inserted in the wrong spot. Fix that.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/elf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index a8a78b55d3ece..c024937eb12a2 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -92,7 +92,7 @@ static inline unsigned long __sym_start(struct symbol *s)
static inline unsigned long __sym_last(struct symbol *s)
{
- return s->offset + s->len - 1;
+ return s->offset + (s->len ? s->len - 1 : 0);
}
INTERVAL_TREE_DEFINE(struct symbol, node, unsigned long, __subtree_last,
--
2.50.0
^ permalink raw reply related
* [PATCH v4 17/63] objtool: Add empty symbols to the symbol tree again
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
The following commit
5da6aea375cd ("objtool: Fix find_{symbol,func}_containing()")
fixed the issue where overlapping symbols weren't getting sorted
properly in the symbol tree. Therefore the workaround to skip adding
empty symbols from the following commit
a2e38dffcd93 ("objtool: Don't add empty symbols to the rbtree")
is no longer needed.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/elf.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 19e249f4783cf..a8a78b55d3ece 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -96,7 +96,8 @@ static inline unsigned long __sym_last(struct symbol *s)
}
INTERVAL_TREE_DEFINE(struct symbol, node, unsigned long, __subtree_last,
- __sym_start, __sym_last, static, __sym)
+ __sym_start, __sym_last, static inline __maybe_unused,
+ __sym)
#define __sym_for_each(_iter, _tree, _start, _end) \
for (_iter = __sym_iter_first((_tree), (_start), (_end)); \
@@ -440,13 +441,6 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym)
list_add(&sym->list, entry);
elf_hash_add(symbol, &sym->hash, sym->idx);
elf_hash_add(symbol_name, &sym->name_hash, str_hash(sym->name));
-
- /*
- * Don't store empty STT_NOTYPE symbols in the rbtree. They
- * can exist within a function, confusing the sorting.
- */
- if (!sym->len)
- __sym_remove(sym, &sym->sec->symbol_tree);
}
static int read_symbols(struct elf *elf)
--
2.50.0
^ permalink raw reply related
* [PATCH v4 16/63] objtool: Remove error handling boilerplate
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Up to a certain point in objtool's execution, all errors are fatal and
return -1. When propagating such errors, just return -1 directly
instead of trying to propagate the original return code. This helps
make the code more compact and the behavior more explicit.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/check.c | 151 +++++++++++++++-------------------------
tools/objtool/special.c | 9 +--
2 files changed, 59 insertions(+), 101 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 6d6323508e4b8..dbdbbddd01ecb 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -430,7 +430,6 @@ static int decode_instructions(struct objtool_file *file)
struct symbol *func;
unsigned long offset;
struct instruction *insn;
- int ret;
for_each_sec(file, sec) {
struct instruction *insns = NULL;
@@ -479,11 +478,8 @@ static int decode_instructions(struct objtool_file *file)
insn->offset = offset;
insn->prev_len = prev_len;
- ret = arch_decode_instruction(file, sec, offset,
- sec->sh.sh_size - offset,
- insn);
- if (ret)
- return ret;
+ if (arch_decode_instruction(file, sec, offset, sec->sh.sh_size - offset, insn))
+ return -1;
prev_len = insn->len;
@@ -599,7 +595,7 @@ static int init_pv_ops(struct objtool_file *file)
};
const char *pv_ops;
struct symbol *sym;
- int idx, nr, ret;
+ int idx, nr;
if (!opts.noinstr)
return 0;
@@ -621,9 +617,8 @@ static int init_pv_ops(struct objtool_file *file)
INIT_LIST_HEAD(&file->pv_ops[idx].targets);
for (idx = 0; (pv_ops = pv_ops_tables[idx]); idx++) {
- ret = add_pv_ops(file, pv_ops);
- if (ret)
- return ret;
+ if (add_pv_ops(file, pv_ops))
+ return -1;
}
return 0;
@@ -1484,7 +1479,6 @@ static int add_jump_destinations(struct objtool_file *file)
struct reloc *reloc;
struct section *dest_sec;
unsigned long dest_off;
- int ret;
for_each_insn(file, insn) {
struct symbol *func = insn_func(insn);
@@ -1507,9 +1501,8 @@ static int add_jump_destinations(struct objtool_file *file)
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc_addend(reloc));
} else if (reloc->sym->retpoline_thunk) {
- ret = add_retpoline_call(file, insn);
- if (ret)
- return ret;
+ if (add_retpoline_call(file, insn))
+ return -1;
continue;
} else if (reloc->sym->return_thunk) {
add_return_call(file, insn, true);
@@ -1519,9 +1512,8 @@ static int add_jump_destinations(struct objtool_file *file)
* External sibling call or internal sibling call with
* STT_FUNC reloc.
*/
- ret = add_call_dest(file, insn, reloc->sym, true);
- if (ret)
- return ret;
+ if (add_call_dest(file, insn, reloc->sym, true))
+ return -1;
continue;
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
@@ -1570,9 +1562,8 @@ static int add_jump_destinations(struct objtool_file *file)
*/
if (jump_dest->sym && jump_dest->offset == jump_dest->sym->offset) {
if (jump_dest->sym->retpoline_thunk) {
- ret = add_retpoline_call(file, insn);
- if (ret)
- return ret;
+ if (add_retpoline_call(file, insn))
+ return -1;
continue;
}
if (jump_dest->sym->return_thunk) {
@@ -1613,9 +1604,8 @@ static int add_jump_destinations(struct objtool_file *file)
* Internal sibling call without reloc or with
* STT_SECTION reloc.
*/
- ret = add_call_dest(file, insn, insn_func(jump_dest), true);
- if (ret)
- return ret;
+ if (add_call_dest(file, insn, insn_func(jump_dest), true))
+ return -1;
continue;
}
@@ -1645,7 +1635,6 @@ static int add_call_destinations(struct objtool_file *file)
unsigned long dest_off;
struct symbol *dest;
struct reloc *reloc;
- int ret;
for_each_insn(file, insn) {
struct symbol *func = insn_func(insn);
@@ -1657,9 +1646,8 @@ static int add_call_destinations(struct objtool_file *file)
dest_off = arch_jump_destination(insn);
dest = find_call_destination(insn->sec, dest_off);
- ret = add_call_dest(file, insn, dest, false);
- if (ret)
- return ret;
+ if (add_call_dest(file, insn, dest, false))
+ return -1;
if (func && func->ignore)
continue;
@@ -1683,19 +1671,16 @@ static int add_call_destinations(struct objtool_file *file)
return -1;
}
- ret = add_call_dest(file, insn, dest, false);
- if (ret)
- return ret;
+ if (add_call_dest(file, insn, dest, false))
+ return -1;
} else if (reloc->sym->retpoline_thunk) {
- ret = add_retpoline_call(file, insn);
- if (ret)
- return ret;
+ if (add_retpoline_call(file, insn))
+ return -1;
} else {
- ret = add_call_dest(file, insn, reloc->sym, false);
- if (ret)
- return ret;
+ if (add_call_dest(file, insn, reloc->sym, false))
+ return -1;
}
}
@@ -1912,7 +1897,6 @@ static int add_special_section_alts(struct objtool_file *file)
struct instruction *orig_insn, *new_insn;
struct special_alt *special_alt, *tmp;
struct alternative *alt;
- int ret;
if (special_get_alts(file->elf, &special_alts))
return -1;
@@ -1944,16 +1928,12 @@ static int add_special_section_alts(struct objtool_file *file)
continue;
}
- ret = handle_group_alt(file, special_alt, orig_insn,
- &new_insn);
- if (ret)
- return ret;
+ if (handle_group_alt(file, special_alt, orig_insn, &new_insn))
+ return -1;
} else if (special_alt->jump_or_nop) {
- ret = handle_jump_alt(file, special_alt, orig_insn,
- &new_insn);
- if (ret)
- return ret;
+ if (handle_jump_alt(file, special_alt, orig_insn, &new_insn))
+ return -1;
}
alt = calloc(1, sizeof(*alt));
@@ -2141,15 +2121,13 @@ static int add_func_jump_tables(struct objtool_file *file,
struct symbol *func)
{
struct instruction *insn;
- int ret;
func_for_each_insn(file, func, insn) {
if (!insn_jump_table(insn))
continue;
- ret = add_jump_table(file, insn);
- if (ret)
- return ret;
+ if (add_jump_table(file, insn))
+ return -1;
}
return 0;
@@ -2163,7 +2141,6 @@ static int add_func_jump_tables(struct objtool_file *file,
static int add_jump_table_alts(struct objtool_file *file)
{
struct symbol *func;
- int ret;
if (!file->rodata)
return 0;
@@ -2173,9 +2150,8 @@ static int add_jump_table_alts(struct objtool_file *file)
continue;
mark_func_jump_tables(file, func);
- ret = add_func_jump_tables(file, func);
- if (ret)
- return ret;
+ if (add_func_jump_tables(file, func))
+ return -1;
}
return 0;
@@ -2299,7 +2275,7 @@ static int read_annotate(struct objtool_file *file,
struct instruction *insn;
struct reloc *reloc;
uint64_t offset;
- int type, ret;
+ int type;
sec = find_section_by_name(file->elf, ".discard.annotate_insn");
if (!sec)
@@ -2329,9 +2305,8 @@ static int read_annotate(struct objtool_file *file,
return -1;
}
- ret = func(file, type, insn);
- if (ret < 0)
- return ret;
+ if (func(file, type, insn))
+ return -1;
}
return 0;
@@ -2540,76 +2515,62 @@ static void mark_rodata(struct objtool_file *file)
static int decode_sections(struct objtool_file *file)
{
- int ret;
-
mark_rodata(file);
- ret = init_pv_ops(file);
- if (ret)
- return ret;
+ if (init_pv_ops(file))
+ return -1;
/*
* Must be before add_{jump_call}_destination.
*/
- ret = classify_symbols(file);
- if (ret)
- return ret;
+ if (classify_symbols(file))
+ return -1;
- ret = decode_instructions(file);
- if (ret)
- return ret;
+ if (decode_instructions(file))
+ return -1;
- ret = add_ignores(file);
- if (ret)
- return ret;
+ if (add_ignores(file))
+ return -1;
add_uaccess_safe(file);
- ret = read_annotate(file, __annotate_early);
- if (ret)
- return ret;
+ if (read_annotate(file, __annotate_early))
+ return -1;
/*
* Must be before add_jump_destinations(), which depends on 'func'
* being set for alternatives, to enable proper sibling call detection.
*/
if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) {
- ret = add_special_section_alts(file);
- if (ret)
- return ret;
+ if (add_special_section_alts(file))
+ return -1;
}
- ret = add_jump_destinations(file);
- if (ret)
- return ret;
+ if (add_jump_destinations(file))
+ return -1;
/*
* Must be before add_call_destination(); it changes INSN_CALL to
* INSN_JUMP.
*/
- ret = read_annotate(file, __annotate_ifc);
- if (ret)
- return ret;
+ if (read_annotate(file, __annotate_ifc))
+ return -1;
- ret = add_call_destinations(file);
- if (ret)
- return ret;
+ if (add_call_destinations(file))
+ return -1;
- ret = add_jump_table_alts(file);
- if (ret)
- return ret;
+ if (add_jump_table_alts(file))
+ return -1;
- ret = read_unwind_hints(file);
- if (ret)
- return ret;
+ if (read_unwind_hints(file))
+ return -1;
/*
* Must be after add_call_destinations() such that it can override
* dead_end_function() marks.
*/
- ret = read_annotate(file, __annotate_late);
- if (ret)
- return ret;
+ if (read_annotate(file, __annotate_late))
+ return -1;
return 0;
}
diff --git a/tools/objtool/special.c b/tools/objtool/special.c
index c80fed8a840ee..c0beefb93b62e 100644
--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -133,7 +133,7 @@ int special_get_alts(struct elf *elf, struct list_head *alts)
struct section *sec;
unsigned int nr_entries;
struct special_alt *alt;
- int idx, ret;
+ int idx;
INIT_LIST_HEAD(alts);
@@ -157,11 +157,8 @@ int special_get_alts(struct elf *elf, struct list_head *alts)
}
memset(alt, 0, sizeof(*alt));
- ret = get_alt_entry(elf, entry, sec, idx, alt);
- if (ret > 0)
- continue;
- if (ret < 0)
- return ret;
+ if (get_alt_entry(elf, entry, sec, idx, alt))
+ return -1;
list_add_tail(&alt->list, alts);
}
--
2.50.0
^ permalink raw reply related
* [PATCH v4 15/63] objtool: Propagate elf_truncate_section() error in elf_write()
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Properly check and propagate the return value of elf_truncate_section()
to avoid silent failures.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/elf.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index b009d9feed760..19e249f4783cf 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -1307,7 +1307,6 @@ static int elf_truncate_section(struct elf *elf, struct section *sec)
for (;;) {
/* get next data descriptor for the relevant section */
data = elf_getdata(s, data);
-
if (!data) {
if (size) {
ERROR("end of section data but non-zero size left\n");
@@ -1343,8 +1342,8 @@ int elf_write(struct elf *elf)
/* Update changed relocation sections and section headers: */
list_for_each_entry(sec, &elf->sections, list) {
- if (sec->truncate)
- elf_truncate_section(elf, sec);
+ if (sec->truncate && elf_truncate_section(elf, sec))
+ return -1;
if (sec_changed(sec)) {
s = elf_getscn(elf->elf, sec->idx);
--
2.50.0
^ permalink raw reply related
* [PATCH v4 14/63] objtool: Fix broken error handling in read_symbols()
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
The free(sym) call in the read_symbols() error path is fundamentally
broken: 'sym' doesn't point to any allocated block. If triggered,
things would go from bad to worse.
Remove the free() and simplify the error paths. Freeing memory isn't
necessary here anyway, these are fatal errors which lead to an immediate
exit().
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/elf.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 1c1bb2cb960da..b009d9feed760 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -492,14 +492,14 @@ static int read_symbols(struct elf *elf)
if (!gelf_getsymshndx(symtab->data, shndx_data, i, &sym->sym,
&shndx)) {
ERROR_ELF("gelf_getsymshndx");
- goto err;
+ return -1;
}
sym->name = elf_strptr(elf->elf, symtab->sh.sh_link,
sym->sym.st_name);
if (!sym->name) {
ERROR_ELF("elf_strptr");
- goto err;
+ return -1;
}
if ((sym->sym.st_shndx > SHN_UNDEF &&
@@ -511,7 +511,7 @@ static int read_symbols(struct elf *elf)
sym->sec = find_section_by_index(elf, shndx);
if (!sym->sec) {
ERROR("couldn't find section for symbol %s", sym->name);
- goto err;
+ return -1;
}
if (GELF_ST_TYPE(sym->sym.st_info) == STT_SECTION) {
sym->name = sym->sec->name;
@@ -581,10 +581,6 @@ static int read_symbols(struct elf *elf)
}
return 0;
-
-err:
- free(sym);
- return -1;
}
static int mark_group_syms(struct elf *elf)
--
2.50.0
^ permalink raw reply related
* [PATCH v4 13/63] objtool: Make find_symbol_containing() less arbitrary
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
In the rare case of overlapping symbols, find_symbol_containing() just
returns the first one it finds. Make it slightly less arbitrary by
returning the smallest symbol with size > 0.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/elf.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index ca5d77db692a2..1c1bb2cb960da 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -193,14 +193,29 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset)
struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset)
{
struct rb_root_cached *tree = (struct rb_root_cached *)&sec->symbol_tree;
- struct symbol *iter;
+ struct symbol *sym = NULL, *tmp;
- __sym_for_each(iter, tree, offset, offset) {
- if (iter->type != STT_SECTION)
- return iter;
+ __sym_for_each(tmp, tree, offset, offset) {
+ if (tmp->len) {
+ if (!sym) {
+ sym = tmp;
+ continue;
+ }
+
+ if (sym->offset != tmp->offset || sym->len != tmp->len) {
+ /*
+ * In the rare case of overlapping symbols,
+ * pick the smaller one.
+ *
+ * TODO: outlaw overlapping symbols
+ */
+ if (tmp->len < sym->len)
+ sym = tmp;
+ }
+ }
}
- return NULL;
+ return sym;
}
/*
--
2.50.0
^ permalink raw reply related
* [PATCH v4 12/63] interval_tree: Fix ITSTATIC usage for *_subtree_search()
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
For consistency with the other function templates, change
_subtree_search_*() to use the user-supplied ITSTATIC rather than the
hard-coded 'static'.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/linux/interval_tree.h | 4 ++++
include/linux/interval_tree_generic.h | 2 +-
include/linux/mm.h | 2 ++
tools/include/linux/interval_tree_generic.h | 2 +-
4 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/linux/interval_tree.h b/include/linux/interval_tree.h
index 2b8026a399064..9d5791e9f737a 100644
--- a/include/linux/interval_tree.h
+++ b/include/linux/interval_tree.h
@@ -19,6 +19,10 @@ extern void
interval_tree_remove(struct interval_tree_node *node,
struct rb_root_cached *root);
+extern struct interval_tree_node *
+interval_tree_subtree_search(struct interval_tree_node *node,
+ unsigned long start, unsigned long last);
+
extern struct interval_tree_node *
interval_tree_iter_first(struct rb_root_cached *root,
unsigned long start, unsigned long last);
diff --git a/include/linux/interval_tree_generic.h b/include/linux/interval_tree_generic.h
index 1b400f26f63d6..c5a2fed49eb0d 100644
--- a/include/linux/interval_tree_generic.h
+++ b/include/linux/interval_tree_generic.h
@@ -77,7 +77,7 @@ ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, \
* Cond2: start <= ITLAST(node) \
*/ \
\
-static ITSTRUCT * \
+ITSTATIC ITSTRUCT * \
ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last) \
{ \
while (true) { \
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1ae97a0b8ec75..69baa9a1e2cb4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3265,6 +3265,8 @@ void vma_interval_tree_insert_after(struct vm_area_struct *node,
struct rb_root_cached *root);
void vma_interval_tree_remove(struct vm_area_struct *node,
struct rb_root_cached *root);
+struct vm_area_struct *vma_interval_tree_subtree_search(struct vm_area_struct *node,
+ unsigned long start, unsigned long last);
struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root_cached *root,
unsigned long start, unsigned long last);
struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
diff --git a/tools/include/linux/interval_tree_generic.h b/tools/include/linux/interval_tree_generic.h
index 1b400f26f63d6..c5a2fed49eb0d 100644
--- a/tools/include/linux/interval_tree_generic.h
+++ b/tools/include/linux/interval_tree_generic.h
@@ -77,7 +77,7 @@ ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, \
* Cond2: start <= ITLAST(node) \
*/ \
\
-static ITSTRUCT * \
+ITSTATIC ITSTRUCT * \
ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last) \
{ \
while (true) { \
--
2.50.0
^ permalink raw reply related
* [PATCH v4 11/63] interval_tree: Sync interval_tree_generic.h with tools
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
The following commit made an improvement to interval_tree_generic.h, but
didn't sync it to the tools copy:
19811285784f ("lib/interval_tree: skip the check before go to the right subtree")
Sync it, and add it to objtool's sync-check.sh so they are more likely
to stay in sync going forward.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/include/linux/interval_tree_generic.h | 8 ++------
tools/objtool/sync-check.sh | 1 +
2 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/tools/include/linux/interval_tree_generic.h b/tools/include/linux/interval_tree_generic.h
index aaa8a0767aa3a..1b400f26f63d6 100644
--- a/tools/include/linux/interval_tree_generic.h
+++ b/tools/include/linux/interval_tree_generic.h
@@ -104,12 +104,8 @@ ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last) \
if (ITSTART(node) <= last) { /* Cond1 */ \
if (start <= ITLAST(node)) /* Cond2 */ \
return node; /* node is leftmost match */ \
- if (node->ITRB.rb_right) { \
- node = rb_entry(node->ITRB.rb_right, \
- ITSTRUCT, ITRB); \
- if (start <= node->ITSUBTREE) \
- continue; \
- } \
+ node = rb_entry(node->ITRB.rb_right, ITSTRUCT, ITRB); \
+ continue; \
} \
return NULL; /* No match */ \
} \
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index 81d120d054425..86d64e3ac6f73 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -16,6 +16,7 @@ arch/x86/include/asm/orc_types.h
arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
+include/linux/interval_tree_generic.h
include/linux/static_call_types.h
"
--
2.50.0
^ permalink raw reply related
* [PATCH v4 10/63] x86/alternative: Refactor INT3 call emulation selftest
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
The INT3 call emulation selftest is a bit fragile as it relies on the
compiler not inserting any extra instructions before the
int3_selftest_ip() definition.
Also, the int3_selftest_ip() symbol overlaps with the int3_selftest
symbol(), which can confuse objtool.
Fix those issues by slightly reworking the functionality and moving
int3_selftest_ip() to a separate asm function. While at it, improve the
naming.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
arch/x86/kernel/alternative.c | 51 +++++++++++++++++++----------------
1 file changed, 28 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 69fb818df2eed..9e7f03172a227 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2244,21 +2244,34 @@ int alternatives_text_reserved(void *start, void *end)
* See entry_{32,64}.S for more details.
*/
-/*
- * We define the int3_magic() function in assembly to control the calling
- * convention such that we can 'call' it from assembly.
- */
-
-extern void int3_magic(unsigned int *ptr); /* defined in asm */
+extern void int3_selftest_asm(unsigned int *ptr);
asm (
" .pushsection .init.text, \"ax\", @progbits\n"
-" .type int3_magic, @function\n"
-"int3_magic:\n"
+" .type int3_selftest_asm, @function\n"
+"int3_selftest_asm:\n"
ANNOTATE_NOENDBR
-" movl $1, (%" _ASM_ARG1 ")\n"
+ /*
+ * INT3 padded with NOP to CALL_INSN_SIZE. The INT3 triggers an
+ * exception, then the int3_exception_nb notifier emulates a call to
+ * int3_selftest_callee().
+ */
+" int3; nop; nop; nop; nop\n"
ASM_RET
-" .size int3_magic, .-int3_magic\n"
+" .size int3_selftest_asm, . - int3_selftest_asm\n"
+" .popsection\n"
+);
+
+extern void int3_selftest_callee(unsigned int *ptr);
+
+asm (
+" .pushsection .init.text, \"ax\", @progbits\n"
+" .type int3_selftest_callee, @function\n"
+"int3_selftest_callee:\n"
+ ANNOTATE_NOENDBR
+" movl $0x1234, (%" _ASM_ARG1 ")\n"
+ ASM_RET
+" .size int3_selftest_callee, . - int3_selftest_callee\n"
" .popsection\n"
);
@@ -2267,7 +2280,7 @@ extern void int3_selftest_ip(void); /* defined in asm below */
static int __init
int3_exception_notify(struct notifier_block *self, unsigned long val, void *data)
{
- unsigned long selftest = (unsigned long)&int3_selftest_ip;
+ unsigned long selftest = (unsigned long)&int3_selftest_asm;
struct die_args *args = data;
struct pt_regs *regs = args->regs;
@@ -2282,7 +2295,7 @@ int3_exception_notify(struct notifier_block *self, unsigned long val, void *data
if (regs->ip - INT3_INSN_SIZE != selftest)
return NOTIFY_DONE;
- int3_emulate_call(regs, (unsigned long)&int3_magic);
+ int3_emulate_call(regs, (unsigned long)&int3_selftest_callee);
return NOTIFY_STOP;
}
@@ -2298,19 +2311,11 @@ static noinline void __init int3_selftest(void)
BUG_ON(register_die_notifier(&int3_exception_nb));
/*
- * Basically: int3_magic(&val); but really complicated :-)
- *
- * INT3 padded with NOP to CALL_INSN_SIZE. The int3_exception_nb
- * notifier above will emulate CALL for us.
+ * Basically: int3_selftest_callee(&val); but really complicated :-)
*/
- asm volatile ("int3_selftest_ip:\n\t"
- ANNOTATE_NOENDBR
- " int3; nop; nop; nop; nop\n\t"
- : ASM_CALL_CONSTRAINT
- : __ASM_SEL_RAW(a, D) (&val)
- : "memory");
+ int3_selftest_asm(&val);
- BUG_ON(val != 1);
+ BUG_ON(val != 0x1234);
unregister_die_notifier(&int3_exception_nb);
}
--
2.50.0
^ permalink raw reply related
* [PATCH v4 09/63] modpost: Ignore unresolved section bounds symbols
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra, Masahiro Yamada
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
In preparation for klp-build livepatch module creation tooling,
suppress warnings for unresolved references to linker-generated
__start_* and __stop_* section bounds symbols.
These symbols are expected to be undefined when modpost runs, as they're
created later by the linker.
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
scripts/mod/modpost.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 5ca7c268294eb..c2b2c8fa6d258 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -606,6 +606,11 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
strstarts(symname, "_savevr_") ||
strcmp(symname, ".TOC.") == 0)
return 1;
+
+ /* ignore linker-created section bounds variables */
+ if (strstarts(symname, "__start_") || strstarts(symname, "__stop_"))
+ return 1;
+
/* Do not ignore this symbol */
return 0;
}
--
2.50.0
^ permalink raw reply related
* [PATCH v4 08/63] kbuild: Remove 'kmod_' prefix from __KBUILD_MODNAME
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra, Masahiro Yamada
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
In preparation for the objtool klp diff subcommand, remove the arbitrary
'kmod_' prefix from __KBUILD_MODNAME and instead add it explicitly in
the __initcall_id() macro.
This change supports the standardization of "unique" symbol naming by
ensuring the non-unique portion of the name comes before the unique
part. That will enable objtool to properly correlate symbols across
builds.
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/linux/init.h | 3 ++-
scripts/Makefile.lib | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/init.h b/include/linux/init.h
index 17c1bc712e234..40331923b9f4a 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -200,12 +200,13 @@ extern struct module __this_module;
/* Format: <modname>__<counter>_<line>_<fn> */
#define __initcall_id(fn) \
+ __PASTE(kmod_, \
__PASTE(__KBUILD_MODNAME, \
__PASTE(__, \
__PASTE(__COUNTER__, \
__PASTE(_, \
__PASTE(__LINE__, \
- __PASTE(_, fn))))))
+ __PASTE(_, fn)))))))
/* Format: __<prefix>__<iid><id> */
#define __initcall_name(prefix, __iid, id) \
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 1d581ba5df66f..b955602661240 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -20,7 +20,7 @@ name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
name-fix = $(call stringify,$(call name-fix-token,$1))
basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
- -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
+ -D__KBUILD_MODNAME=$(call name-fix-token,$(modname))
modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
--
2.50.0
^ permalink raw reply related
* [PATCH v4 07/63] elfnote: Change ELFNOTE() to use __UNIQUE_ID()
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
In preparation for the objtool klp diff subcommand, replace the custom
unique symbol name generation in ELFNOTE() with __UNIQUE_ID().
This standardizes the naming format for all "unique" symbols, which will
allow objtool to properly correlate them. Note this also removes the
"one ELF note per line" limitation.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/linux/elfnote.h | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/include/linux/elfnote.h b/include/linux/elfnote.h
index 69b136e4dd2b6..bb3dcded055fc 100644
--- a/include/linux/elfnote.h
+++ b/include/linux/elfnote.h
@@ -60,23 +60,21 @@
#else /* !__ASSEMBLER__ */
#include <uapi/linux/elf.h>
+#include <linux/compiler.h>
/*
* Use an anonymous structure which matches the shape of
* Elf{32,64}_Nhdr, but includes the name and desc data. The size and
* type of name and desc depend on the macro arguments. "name" must
- * be a literal string, and "desc" must be passed by value. You may
- * only define one note per line, since __LINE__ is used to generate
- * unique symbols.
+ * be a literal string, and "desc" must be passed by value.
*/
-#define _ELFNOTE_PASTE(a,b) a##b
-#define _ELFNOTE(size, name, unique, type, desc) \
+#define ELFNOTE(size, name, type, desc) \
static const struct { \
struct elf##size##_note _nhdr; \
unsigned char _name[sizeof(name)] \
__attribute__((aligned(sizeof(Elf##size##_Word)))); \
typeof(desc) _desc \
__attribute__((aligned(sizeof(Elf##size##_Word)))); \
- } _ELFNOTE_PASTE(_note_, unique) \
+ } __UNIQUE_ID(note) \
__used \
__attribute__((section(".note." name), \
aligned(sizeof(Elf##size##_Word)), \
@@ -89,11 +87,10 @@
name, \
desc \
}
-#define ELFNOTE(size, name, type, desc) \
- _ELFNOTE(size, name, __LINE__, type, desc)
#define ELFNOTE32(name, type, desc) ELFNOTE(32, name, type, desc)
#define ELFNOTE64(name, type, desc) ELFNOTE(64, name, type, desc)
+
#endif /* __ASSEMBLER__ */
#endif /* _LINUX_ELFNOTE_H */
--
2.50.0
^ permalink raw reply related
* [PATCH v4 06/63] compiler.h: Make addressable symbols less of an eyesore
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Avoid underscore overload by changing:
__UNIQUE_ID___addressable_loops_per_jiffy_868
to the following:
__UNIQUE_ID_addressable_loops_per_jiffy_868
This matches the format used by other __UNIQUE_ID()-generated symbols
and improves readability for those who stare at ELF symbol table dumps.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/linux/compiler.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index db5796b8b0a71..9bc690be60675 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -287,7 +287,7 @@ static inline void *offset_to_ptr(const int *off)
*/
#define ___ADDRESSABLE(sym, __attrs) \
static void * __used __attrs \
- __UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)(uintptr_t)&sym;
+ __UNIQUE_ID(__PASTE(addressable_, sym)) = (void *)(uintptr_t)&sym;
#define __ADDRESSABLE(sym) \
___ADDRESSABLE(sym, __section(".discard.addressable"))
--
2.50.0
^ permalink raw reply related
* [PATCH v4 05/63] compiler: Tweak __UNIQUE_ID() naming
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
In preparation for the objtool klp diff subcommand, add an underscore
between the name and the counter. This will make it possible for
objtool to distinguish between the non-unique and unique parts of the
symbol name so it can properly correlate the symbols.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/linux/compiler.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 64ff73c533e54..db5796b8b0a71 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -163,7 +163,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
__asm__ ("" : "=r" (var) : "0" (var))
#endif
-#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
+/* Format: __UNIQUE_ID_<name>_<__COUNTER__> */
+#define __UNIQUE_ID(name) \
+ __PASTE(__UNIQUE_ID_, \
+ __PASTE(name, \
+ __PASTE(_, __COUNTER__)))
/**
* data_race - mark an expression as containing intentional data races
--
2.50.0
^ permalink raw reply related
* [PATCH v4 04/63] x86/kprobes: Remove STACK_FRAME_NON_STANDARD annotation
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Since commit 877b145f0f47 ("x86/kprobes: Move trampoline code into
RODATA"), the optprobe template code is no longer analyzed by objtool so
it doesn't need to be ignored.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
arch/x86/kernel/kprobes/opt.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 0aabd4c4e2c4f..6f826a00eca29 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -103,7 +103,6 @@ static void synthesize_set_arg1(kprobe_opcode_t *addr, unsigned long val)
asm (
".pushsection .rodata\n"
- "optprobe_template_func:\n"
".global optprobe_template_entry\n"
"optprobe_template_entry:\n"
#ifdef CONFIG_X86_64
@@ -160,9 +159,6 @@ asm (
"optprobe_template_end:\n"
".popsection\n");
-void optprobe_template_func(void);
-STACK_FRAME_NON_STANDARD(optprobe_template_func);
-
#define TMPL_CLAC_IDX \
((long)optprobe_template_clac - (long)optprobe_template_entry)
#define TMPL_MOVE_IDX \
--
2.50.0
^ permalink raw reply related
* [PATCH v4 03/63] x86/module: Improve relocation error messages
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
Add the section number and reloc index to relocation error messages to
help find the faulty relocation.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
arch/x86/kernel/module.c | 15 +++++++++------
kernel/livepatch/core.c | 4 ++--
2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 0ffbae902e2fe..11c45ce42694c 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -97,6 +97,7 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs,
DEBUGP("%s relocate section %u to %u\n",
apply ? "Applying" : "Clearing",
relsec, sechdrs[relsec].sh_info);
+
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
size_t size;
@@ -162,15 +163,17 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs,
if (apply) {
if (memcmp(loc, &zero, size)) {
- pr_err("x86/modules: Invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n",
- (int)ELF64_R_TYPE(rel[i].r_info), loc, val);
+ pr_err("x86/modules: Invalid relocation target, existing value is nonzero for sec %u, idx %u, type %d, loc %lx, val %llx\n",
+ relsec, i, (int)ELF64_R_TYPE(rel[i].r_info),
+ (unsigned long)loc, val);
return -ENOEXEC;
}
write(loc, &val, size);
} else {
if (memcmp(loc, &val, size)) {
- pr_warn("x86/modules: Invalid relocation target, existing value does not match expected value for type %d, loc %p, val %Lx\n",
- (int)ELF64_R_TYPE(rel[i].r_info), loc, val);
+ pr_warn("x86/modules: Invalid relocation target, existing value does not match expected value for sec %u, idx %u, type %d, loc %lx, val %llx\n",
+ relsec, i, (int)ELF64_R_TYPE(rel[i].r_info),
+ (unsigned long)loc, val);
return -ENOEXEC;
}
write(loc, &zero, size);
@@ -179,8 +182,8 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs,
return 0;
overflow:
- pr_err("overflow in relocation type %d val %Lx\n",
- (int)ELF64_R_TYPE(rel[i].r_info), val);
+ pr_err("overflow in relocation type %d val %llx sec %u idx %d\n",
+ (int)ELF64_R_TYPE(rel[i].r_info), val, relsec, i);
pr_err("`%s' likely not compiled with -mcmodel=kernel\n",
me->name);
return -ENOEXEC;
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 0e73fac55f8eb..7e443c2cf7d48 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -217,8 +217,8 @@ static int klp_resolve_symbols(Elf_Shdr *sechdrs, const char *strtab,
for (i = 0; i < relasec->sh_size / sizeof(Elf_Rela); i++) {
sym = (Elf_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
if (sym->st_shndx != SHN_LIVEPATCH) {
- pr_err("symbol %s is not marked as a livepatch symbol\n",
- strtab + sym->st_name);
+ pr_err("symbol %s at rela sec %u idx %d is not marked as a livepatch symbol\n",
+ strtab + sym->st_name, symndx, i);
return -EINVAL;
}
--
2.50.0
^ permalink raw reply related
* [PATCH v4 02/63] vmlinux.lds: Unify TEXT_MAIN, DATA_MAIN, and related macros
From: Josh Poimboeuf @ 2025-09-17 16:03 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Petr Mladek, Miroslav Benes, Joe Lawrence,
live-patching, Song Liu, laokz, Jiri Kosina,
Marcos Paulo de Souza, Weinan Liu, Fazla Mehrab, Chen Zhongjin,
Puranjay Mohan, Dylan Hatch, Peter Zijlstra, Heiko Carstens,
Vasily Gorbik, Alexander Gordeev
In-Reply-To: <cover.1758067942.git.jpoimboe@kernel.org>
TEXT_MAIN, DATA_MAIN and friends are defined differently depending on
whether certain config options enable -ffunction-sections and/or
-fdata-sections.
There's no technical reason for that beyond voodoo coding. Keeping the
separate implementations adds unnecessary complexity, fragments the
logic, and increases the risk of subtle bugs.
Unify the macros by using the same input section patterns across all
configs.
This is a prerequisite for the upcoming livepatch klp-build tooling
which will manually enable -ffunction-sections and -fdata-sections via
KCFLAGS.
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
include/asm-generic/vmlinux.lds.h | 40 ++++++++++---------------------
scripts/module.lds.S | 12 ++++------
2 files changed, 17 insertions(+), 35 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index ae2d2359b79e9..6b2311fa41393 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -87,39 +87,24 @@
#define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT)
/*
- * LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which
- * generates .data.identifier sections, which need to be pulled in with
- * .data. We don't want to pull in .data..other sections, which Linux
- * has defined. Same for text and bss.
+ * Support -ffunction-sections by matching .text and .text.*,
+ * but exclude '.text..*'.
*
- * With LTO_CLANG, the linker also splits sections by default, so we need
- * these macros to combine the sections during the final link.
- *
- * With AUTOFDO_CLANG and PROPELLER_CLANG, by default, the linker splits
- * text sections and regroups functions into subsections.
- *
- * RODATA_MAIN is not used because existing code already defines .rodata.x
- * sections to be brought in with rodata.
+ * Special .text.* sections that are typically grouped separately, such as
+ * .text.unlikely or .text.hot, must be matched explicitly before using
+ * TEXT_MAIN.
*/
-#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) || \
-defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
#define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
-#else
-#define TEXT_MAIN .text
-#endif
-#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG)
+
+/*
+ * Support -fdata-sections by matching .data, .data.*, and others,
+ * but exclude '.data..*'.
+ */
#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data.rel.* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$L*
#define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]*
#define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L*
#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..L* .bss..compoundliteral*
#define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]*
-#else
-#define DATA_MAIN .data .data.rel .data.rel.local
-#define SDATA_MAIN .sdata
-#define RODATA_MAIN .rodata
-#define BSS_MAIN .bss
-#define SBSS_MAIN .sbss
-#endif
/*
* GCC 4.5 and later have a 32 bytes section alignment for structures.
@@ -580,9 +565,8 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
* during second ld run in second ld pass when generating System.map
*
* TEXT_MAIN here will match symbols with a fixed pattern (for example,
- * .text.hot or .text.unlikely) if dead code elimination or
- * function-section is enabled. Match these symbols first before
- * TEXT_MAIN to ensure they are grouped together.
+ * .text.hot or .text.unlikely). Match those before TEXT_MAIN to ensure
+ * they get grouped together.
*
* Also placing .text.hot section at the beginning of a page, this
* would help the TLB performance.
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index ee79c41059f3d..2632c6cb8ebe7 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -38,12 +38,10 @@ SECTIONS {
__kcfi_traps : { KEEP(*(.kcfi_traps)) }
#endif
-#ifdef CONFIG_LTO_CLANG
- /*
- * With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and
- * -ffunction-sections, which increases the size of the final module.
- * Merge the split sections in the final binary.
- */
+ .text : {
+ *(.text .text.[0-9a-zA-Z_]*)
+ }
+
.bss : {
*(.bss .bss.[0-9a-zA-Z_]*)
*(.bss..L*)
@@ -58,7 +56,7 @@ SECTIONS {
*(.rodata .rodata.[0-9a-zA-Z_]*)
*(.rodata..L*)
}
-#endif
+
MOD_SEPARATE_CODETAG_SECTIONS()
}
--
2.50.0
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