* [PATCH v2 00/10] powerpc: Modernize unhandled signals message
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
Hi, everyone.
This series was inspired by the need to modernize and display more
informative messages about unhandled signals.
The "unhandled signal NN" is not very informative. We thought it would be
helpful adding a human-readable message describing what the signal number
means, printing the VMA address, and dumping the instructions.
We can add more informative messages, like informing what each code of a
SIGSEGV signal means. We are open to suggestions.
Before this series:
pandafault[5815]: unhandled signal 11 at 00000000100007d0 nip 000000001000061c lr 00003fff87ff5100 code 2
After this series:
pandafault[10850]: segfault (11) at 00000000100007d0 nip 000000001000061c lr 00007fff9f3e5100 code 2 in pandafault[10000000+10000]
pandafault[10850]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
pandafault[10850]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040
Link to v1:
https://lore.kernel.org/lkml/20180724192720.32417-1-muriloo@linux.ibm.com/
v1..v2:
- Broke patch 7 down into patches 7-9
- Added proper copyright in arch/powerpc/include/asm/stacktrace.h
- show_instructions(): prefixed lines with current->comm and current->pid
Cheers!
Murilo Opsfelder Araujo (10):
powerpc/traps: Print unhandled signals in a separate function
powerpc/traps: Return early in show_signal_msg()
powerpc/reg: Add REG_FMT definition
powerpc/traps: Use REG_FMT in show_signal_msg()
powerpc/traps: Print VMA for unhandled signals
powerpc/traps: Print signal name for unhandled signals
powerpc: Do not call __kernel_text_address() in show_instructions()
powerpc: Add stacktrace.h header
powerpc/traps: Show instructions on exceptions
powerpc/traps: Add line prefix in show_instructions()
arch/powerpc/include/asm/reg.h | 6 +++
arch/powerpc/include/asm/stacktrace.h | 13 +++++
arch/powerpc/kernel/process.c | 35 ++++++-------
arch/powerpc/kernel/traps.c | 73 +++++++++++++++++++++++----
4 files changed, 100 insertions(+), 27 deletions(-)
create mode 100644 arch/powerpc/include/asm/stacktrace.h
--
2.17.1
^ permalink raw reply
* [PATCH v2 01/10] powerpc/traps: Print unhandled signals in a separate function
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Isolate the logic of printing unhandled signals out of _exception_pkey().
No functional change, only code rearrangement.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/traps.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 0e17dcb48720..cbd3dc365193 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -301,26 +301,32 @@ void user_single_step_siginfo(struct task_struct *tsk,
info->si_addr = (void __user *)regs->nip;
}
+static void show_signal_msg(int signr, struct pt_regs *regs, int code,
+ unsigned long addr)
+{
+ const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
+ "at %08lx nip %08lx lr %08lx code %x\n";
+ const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
+ "at %016lx nip %016lx lr %016lx code %x\n";
+
+ if (show_unhandled_signals && unhandled_signal(current, signr)) {
+ printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
+ current->comm, current->pid, signr,
+ addr, regs->nip, regs->link, code);
+ }
+}
void _exception_pkey(int signr, struct pt_regs *regs, int code,
- unsigned long addr, int key)
+ unsigned long addr, int key)
{
siginfo_t info;
- const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
- "at %08lx nip %08lx lr %08lx code %x\n";
- const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
- "at %016lx nip %016lx lr %016lx code %x\n";
if (!user_mode(regs)) {
die("Exception in kernel mode", regs, signr);
return;
}
- if (show_unhandled_signals && unhandled_signal(current, signr)) {
- printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
- current->comm, current->pid, signr,
- addr, regs->nip, regs->link, code);
- }
+ show_signal_msg(signr, regs, code, addr);
if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs))
local_irq_enable();
--
2.17.1
^ permalink raw reply related
* [PATCH v2 02/10] powerpc/traps: Return early in show_signal_msg()
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Modify the logic of show_signal_msg() to return early, if possible.
Replace printk_ratelimited() by printk() and a default rate limit burst to
limit displaying unhandled signals messages.
Mainly reason of this change is to improve readability of the function.
The conditions to display the message were coupled together in one single
`if` statement.
Splitting out the rate limit check outside show_signal_msg() makes it
easier to the caller decide if it wants to respect a printk rate limit or
not.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/traps.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index cbd3dc365193..4faab4705774 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -301,6 +301,13 @@ void user_single_step_siginfo(struct task_struct *tsk,
info->si_addr = (void __user *)regs->nip;
}
+static bool show_unhandled_signals_ratelimited(void)
+{
+ static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+ return show_unhandled_signals && __ratelimit(&rs);
+}
+
static void show_signal_msg(int signr, struct pt_regs *regs, int code,
unsigned long addr)
{
@@ -309,11 +316,12 @@ static void show_signal_msg(int signr, struct pt_regs *regs, int code,
const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
"at %016lx nip %016lx lr %016lx code %x\n";
- if (show_unhandled_signals && unhandled_signal(current, signr)) {
- printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
- current->comm, current->pid, signr,
- addr, regs->nip, regs->link, code);
- }
+ if (!unhandled_signal(current, signr))
+ return;
+
+ printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
+ current->comm, current->pid, signr,
+ addr, regs->nip, regs->link, code);
}
void _exception_pkey(int signr, struct pt_regs *regs, int code,
@@ -326,7 +334,8 @@ void _exception_pkey(int signr, struct pt_regs *regs, int code,
return;
}
- show_signal_msg(signr, regs, code, addr);
+ if (show_unhandled_signals_ratelimited())
+ show_signal_msg(signr, regs, code, addr);
if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs))
local_irq_enable();
--
2.17.1
^ permalink raw reply related
* [PATCH v2 03/10] powerpc/reg: Add REG_FMT definition
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Make REG definition, in arch/powerpc/kernel/process.c, generic enough by
renaming it to REG_FMT and placing it in arch/powerpc/include/asm/reg.h to
be used elsewhere.
Replace occurrences of REG by REG_FMT in arch/powerpc/kernel/process.c.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/include/asm/reg.h | 6 ++++++
arch/powerpc/kernel/process.c | 22 ++++++++++------------
2 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 858aa7984ab0..d6c5c77383de 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1319,6 +1319,12 @@
#define PVR_ARCH_207 0x0f000004
#define PVR_ARCH_300 0x0f000005
+#ifdef CONFIG_PPC64
+#define REG_FMT "%016lx"
+#else
+#define REG_FMT "%08lx"
+#endif /* CONFIG_PPC64 */
+
/* Macros for setting and retrieving special purpose registers */
#ifndef __ASSEMBLY__
#define mfmsr() ({unsigned long rval; \
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index e9533b4d2f08..25b562c21b7b 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1381,11 +1381,9 @@ static void print_msr_bits(unsigned long val)
}
#ifdef CONFIG_PPC64
-#define REG "%016lx"
#define REGS_PER_LINE 4
#define LAST_VOLATILE 13
#else
-#define REG "%08lx"
#define REGS_PER_LINE 8
#define LAST_VOLATILE 12
#endif
@@ -1396,21 +1394,21 @@ void show_regs(struct pt_regs * regs)
show_regs_print_info(KERN_DEFAULT);
- printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
+ printk("NIP: "REG_FMT" LR: "REG_FMT" CTR: "REG_FMT"\n",
regs->nip, regs->link, regs->ctr);
printk("REGS: %px TRAP: %04lx %s (%s)\n",
regs, regs->trap, print_tainted(), init_utsname()->release);
- printk("MSR: "REG" ", regs->msr);
+ printk("MSR: "REG_FMT" ", regs->msr);
print_msr_bits(regs->msr);
- pr_cont(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer);
+ pr_cont(" CR: "REG_FMT" XER: "REG_FMT"\n", regs->ccr, regs->xer);
trap = TRAP(regs);
if ((TRAP(regs) != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
- pr_cont("CFAR: "REG" ", regs->orig_gpr3);
+ pr_cont("CFAR: "REG_FMT" ", regs->orig_gpr3);
if (trap == 0x200 || trap == 0x300 || trap == 0x600)
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
- pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
+ pr_cont("DEAR: "REG_FMT" ESR: "REG_FMT" ", regs->dar, regs->dsisr);
#else
- pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
+ pr_cont("DAR: "REG_FMT" DSISR: "REG_FMT" ", regs->dar, regs->dsisr);
#endif
#ifdef CONFIG_PPC64
pr_cont("IRQMASK: %lx ", regs->softe);
@@ -1423,7 +1421,7 @@ void show_regs(struct pt_regs * regs)
for (i = 0; i < 32; i++) {
if ((i % REGS_PER_LINE) == 0)
pr_cont("\nGPR%02d: ", i);
- pr_cont(REG " ", regs->gpr[i]);
+ pr_cont(REG_FMT " ", regs->gpr[i]);
if (i == LAST_VOLATILE && !FULL_REGS(regs))
break;
}
@@ -1433,8 +1431,8 @@ void show_regs(struct pt_regs * regs)
* Lookup NIP late so we have the best change of getting the
* above info out without failing
*/
- printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
- printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
+ printk("NIP ["REG_FMT"] %pS\n", regs->nip, (void *)regs->nip);
+ printk("LR ["REG_FMT"] %pS\n", regs->link, (void *)regs->link);
#endif
show_stack(current, (unsigned long *) regs->gpr[1]);
if (!user_mode(regs))
@@ -2038,7 +2036,7 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
newsp = stack[0];
ip = stack[STACK_FRAME_LR_SAVE];
if (!firstframe || ip != lr) {
- printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
+ printk("["REG_FMT"] ["REG_FMT"] %pS", sp, ip, (void *)ip);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if ((ip == rth) && curr_frame >= 0) {
pr_cont(" (%pS)",
--
2.17.1
^ permalink raw reply related
* [PATCH v2 05/10] powerpc/traps: Print VMA for unhandled signals
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
This adds VMA address in the message printed for unhandled signals,
similarly to what other architectures, like x86, print.
Before this patch, a page fault looked like:
pandafault[61470]: unhandled signal 11 at 00000000100007d0 nip 000000001000061c lr 00007fff8d185100 code 2
After this patch, a page fault looks like:
pandafault[6303]: unhandled signal 11 at 00000000100007d0 nip 000000001000061c lr 00007fff93c55100 code 2 in pandafault[10000000+10000]
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/traps.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 047d980ac776..e6c43ef9fb50 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -315,9 +315,13 @@ static void show_signal_msg(int signr, struct pt_regs *regs, int code,
return;
pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
- " nip "REG_FMT" lr "REG_FMT" code %x\n",
+ " nip "REG_FMT" lr "REG_FMT" code %x",
current->comm, current->pid, signr, addr,
regs->nip, regs->link, code);
+
+ print_vma_addr(KERN_CONT " in ", regs->nip);
+
+ pr_cont("\n");
}
void _exception_pkey(int signr, struct pt_regs *regs, int code,
--
2.17.1
^ permalink raw reply related
* [PATCH v2 06/10] powerpc/traps: Print signal name for unhandled signals
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
This adds a human-readable name in the unhandled signal message.
Before this patch, a page fault looked like:
pandafault[6303]: unhandled signal 11 at 00000000100007d0 nip 000000001000061c lr 00007fff93c55100 code 2 in pandafault[10000000+10000]
After this patch, a page fault looks like:
pandafault[6352]: segfault (11) at 000000013a2a09f8 nip 000000013a2a086c lr 00007fffb63e5100 code 2 in pandafault[13a2a0000+10000]
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/traps.c | 43 +++++++++++++++++++++++++++++++++----
1 file changed, 39 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index e6c43ef9fb50..e55ee639d010 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -96,6 +96,41 @@ EXPORT_SYMBOL(__debugger_fault_handler);
#define TM_DEBUG(x...) do { } while(0)
#endif
+static const char *signames[SIGRTMIN + 1] = {
+ "UNKNOWN",
+ "SIGHUP", // 1
+ "SIGINT", // 2
+ "SIGQUIT", // 3
+ "SIGILL", // 4
+ "unhandled trap", // 5 = SIGTRAP
+ "SIGABRT", // 6 = SIGIOT
+ "bus error", // 7 = SIGBUS
+ "floating point exception", // 8 = SIGFPE
+ "illegal instruction", // 9 = SIGILL
+ "SIGUSR1", // 10
+ "segfault", // 11 = SIGSEGV
+ "SIGUSR2", // 12
+ "SIGPIPE", // 13
+ "SIGALRM", // 14
+ "SIGTERM", // 15
+ "SIGSTKFLT", // 16
+ "SIGCHLD", // 17
+ "SIGCONT", // 18
+ "SIGSTOP", // 19
+ "SIGTSTP", // 20
+ "SIGTTIN", // 21
+ "SIGTTOU", // 22
+ "SIGURG", // 23
+ "SIGXCPU", // 24
+ "SIGXFSZ", // 25
+ "SIGVTALRM", // 26
+ "SIGPROF", // 27
+ "SIGWINCH", // 28
+ "SIGIO", // 29 = SIGPOLL = SIGLOST
+ "SIGPWR", // 30
+ "SIGSYS", // 31 = SIGUNUSED
+};
+
/*
* Trap & Exception support
*/
@@ -314,10 +349,10 @@ static void show_signal_msg(int signr, struct pt_regs *regs, int code,
if (!unhandled_signal(current, signr))
return;
- pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
- " nip "REG_FMT" lr "REG_FMT" code %x",
- current->comm, current->pid, signr, addr,
- regs->nip, regs->link, code);
+ pr_info("%s[%d]: %s (%d) at "REG_FMT" nip "REG_FMT \
+ " lr "REG_FMT" code %x",
+ current->comm, current->pid, signames[signr],
+ signr, addr, regs->nip, regs->link, code);
print_vma_addr(KERN_CONT " in ", regs->nip);
--
2.17.1
^ permalink raw reply related
* [PATCH v2 04/10] powerpc/traps: Use REG_FMT in show_signal_msg()
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Simplify the message format by using REG_FMT as the register format. This
avoids having two different formats and avoids checking for MSR_64BIT.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/traps.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 4faab4705774..047d980ac776 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -311,17 +311,13 @@ static bool show_unhandled_signals_ratelimited(void)
static void show_signal_msg(int signr, struct pt_regs *regs, int code,
unsigned long addr)
{
- const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
- "at %08lx nip %08lx lr %08lx code %x\n";
- const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
- "at %016lx nip %016lx lr %016lx code %x\n";
-
if (!unhandled_signal(current, signr))
return;
- printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
- current->comm, current->pid, signr,
- addr, regs->nip, regs->link, code);
+ pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
+ " nip "REG_FMT" lr "REG_FMT" code %x\n",
+ current->comm, current->pid, signr, addr,
+ regs->nip, regs->link, code);
}
void _exception_pkey(int signr, struct pt_regs *regs, int code,
--
2.17.1
^ permalink raw reply related
* [PATCH v2 07/10] powerpc: Do not call __kernel_text_address() in show_instructions()
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Modify show_instructions() not to call __kernel_text_address(), allowing
userspace instruction dump. probe_kernel_address(), which returns -EFAULT
if something goes wrong, is still being called.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/process.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 25b562c21b7b..04960796fcce 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1283,8 +1283,7 @@ static void show_instructions(struct pt_regs *regs)
pc = (unsigned long)phys_to_virt(pc);
#endif
- if (!__kernel_text_address(pc) ||
- probe_kernel_address((unsigned int __user *)pc, instr)) {
+ if (probe_kernel_address((unsigned int __user *)pc, instr)) {
pr_cont("XXXXXXXX ");
} else {
if (regs->nip == pc)
--
2.17.1
^ permalink raw reply related
* [PATCH v2 08/10] powerpc: Add stacktrace.h header
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Move show_instructions() declaration to
arch/powerpc/include/asm/stacktrace.h and include asm/stracktrace.h in
arch/powerpc/kernel/process.c, which contains the implementation.
This allows show_instructions() to be called on, for example,
show_signal_msg().
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/include/asm/stacktrace.h | 13 +++++++++++++
arch/powerpc/kernel/process.c | 3 ++-
2 files changed, 15 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/include/asm/stacktrace.h
diff --git a/arch/powerpc/include/asm/stacktrace.h b/arch/powerpc/include/asm/stacktrace.h
new file mode 100644
index 000000000000..217ebc52ff97
--- /dev/null
+++ b/arch/powerpc/include/asm/stacktrace.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Stack trace functions.
+ *
+ * Copyright 2018, Murilo Opsfelder Araujo, IBM Corporation.
+ */
+
+#ifndef _ASM_POWERPC_STACKTRACE_H
+#define _ASM_POWERPC_STACKTRACE_H
+
+void show_instructions(struct pt_regs *regs);
+
+#endif /* _ASM_POWERPC_STACKTRACE_H */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 04960796fcce..709bfb524b84 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -52,6 +52,7 @@
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/runlatch.h>
+#include <asm/stacktrace.h>
#include <asm/syscalls.h>
#include <asm/switch_to.h>
#include <asm/tm.h>
@@ -1261,7 +1262,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
static int instructions_to_print = 16;
-static void show_instructions(struct pt_regs *regs)
+void show_instructions(struct pt_regs *regs)
{
int i;
unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
--
2.17.1
^ permalink raw reply related
* [PATCH v2 09/10] powerpc/traps: Show instructions on exceptions
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Call show_instructions() in arch/powerpc/kernel/traps.c to dump
instructions at faulty location, useful to debugging.
Before this patch, an unhandled signal message looked like:
pandafault[10524]: segfault (11) at 00000000100007d0 nip 000000001000061c lr 00007fffbd295100 code 2 in pandafault[10000000+10000]
After this patch, it looks like:
pandafault[10524]: segfault (11) at 00000000100007d0 nip 000000001000061c lr 00007fffbd295100 code 2 in pandafault[10000000+10000]
Instruction dump:
4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/traps.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index e55ee639d010..3beca17ac1b1 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -70,6 +70,7 @@
#include <asm/hmi.h>
#include <sysdev/fsl_pci.h>
#include <asm/kprobes.h>
+#include <asm/stacktrace.h>
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE)
int (*__debugger)(struct pt_regs *regs) __read_mostly;
@@ -357,6 +358,8 @@ static void show_signal_msg(int signr, struct pt_regs *regs, int code,
print_vma_addr(KERN_CONT " in ", regs->nip);
pr_cont("\n");
+
+ show_instructions(regs);
}
void _exception_pkey(int signr, struct pt_regs *regs, int code,
--
2.17.1
^ permalink raw reply related
* [PATCH v2 10/10] powerpc/traps: Add line prefix in show_instructions()
From: Murilo Opsfelder Araujo @ 2018-07-27 14:58 UTC (permalink / raw)
To: linux-kernel
Cc: Alastair D'Silva, Andrew Donnellan, Balbir Singh,
Benjamin Herrenschmidt, Christophe Leroy, Cyril Bur,
Eric W . Biederman, Michael Ellerman, Michael Neuling,
Murilo Opsfelder Araujo, Nicholas Piggin, Paul Mackerras,
Simon Guo, Sukadev Bhattiprolu, Tobin C . Harding, linuxppc-dev
In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com>
Remove "Instruction dump:" line by adding a prefix to display current->comm
and current->pid, along with the instructions dump.
The prefix can serve as a glue that links the instructions dump to its
originator, allowing messages to be interleaved in the logs.
Before this patch, a page fault looked like:
pandafault[10524]: segfault (11) at 00000000100007d0 nip 000000001000061c lr 00007fffbd295100 code 2 in pandafault[10000000+10000]
Instruction dump:
4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040
After this patch, it looks like:
pandafault[10850]: segfault (11) at 00000000100007d0 nip 000000001000061c lr 00007fff9f3e5100 code 2 in pandafault[10000000+10000]
pandafault[10850]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
pandafault[10850]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
arch/powerpc/kernel/process.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 709bfb524b84..25b6dfc8dd81 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1265,16 +1265,19 @@ static int instructions_to_print = 16;
void show_instructions(struct pt_regs *regs)
{
int i;
+ const char *prefix = KERN_INFO "%s[%d]: code: ";
unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
sizeof(int));
- printk("Instruction dump:");
+ printk(prefix, current->comm, current->pid);
for (i = 0; i < instructions_to_print; i++) {
int instr;
- if (!(i % 8))
+ if (!(i % 8) && (i > 0)) {
pr_cont("\n");
+ printk(prefix, current->comm, current->pid);
+ }
#if !defined(CONFIG_BOOKE)
/* If executing with the IMMU off, adjust pc rather
--
2.17.1
^ permalink raw reply related
* Re: [PATCH resend] powerpc/64s: fix page table fragment refcount race vs speculative references
From: Matthew Wilcox @ 2018-07-27 15:38 UTC (permalink / raw)
To: Nicholas Piggin
Cc: linuxppc-dev, Andrew Morton, Linus Torvalds, Aneesh Kumar K . V,
linux-mm
In-Reply-To: <20180728002906.531d0211@roar.ozlabs.ibm.com>
On Sat, Jul 28, 2018 at 12:29:06AM +1000, Nicholas Piggin wrote:
> On Fri, 27 Jul 2018 06:41:56 -0700
> Matthew Wilcox <willy@infradead.org> wrote:
>
> > On Fri, Jul 27, 2018 at 09:48:17PM +1000, Nicholas Piggin wrote:
> > > The page table fragment allocator uses the main page refcount racily
> > > with respect to speculative references. A customer observed a BUG due
> > > to page table page refcount underflow in the fragment allocator. This
> > > can be caused by the fragment allocator set_page_count stomping on a
> > > speculative reference, and then the speculative failure handler
> > > decrements the new reference, and the underflow eventually pops when
> > > the page tables are freed.
> >
> > Oof. Can't you fix this instead by using page_ref_add() instead of
> > set_page_count()?
>
> It's ugly doing it that way. The problem is we have a page table
> destructor and that would be missed if the spec ref was the last
> put. In practice with RCU page table freeing maybe you can say
> there will be no spec ref there (unless something changes), but
> still it just seems much simpler doing this and avoiding any
> complexity or relying on other synchronization.
I don't want to rely on the speculative reference not happening by the
time the page table is torn down; that's way too black-magic for me.
Another possibility would be to use, say, the top 16 bits of the
atomic for your counter and call the dtor once the atomic is below 64k.
I'm also thinking about overhauling the dtor system so it's not tied to
compound pages; anyone with a bit in page_type would be able to use it.
That way you'd always get your dtor called, even if the speculative
reference was the last one.
> > > Any objection to the struct page change to grab the arch specific
> > > page table page word for powerpc to use? If not, then this should
> > > go via powerpc tree because it's inconsequential for core mm.
> >
> > I want (eventually) to get to the point where every struct page carries
> > a pointer to the struct mm that it belongs to. It's good for debugging
> > as well as handling memory errors in page tables.
>
> That doesn't seem like it should be a problem, there's some spare
> words there for arch independent users.
Could you take one of the spare words instead then? My intent was to
just take the 'x86 pgds only' comment off that member. _pt_pad_2 looks
ideal because it'll be initialised to 0 and you'll return it to 0 by
the time you're done.
^ permalink raw reply
* Re: [PATCH 0/6] lib/crc32: treewide: Use existing define with polynomial
From: Herbert Xu @ 2018-07-27 16:05 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: David S. Miller, Maxime Coquelin, Alexandre Torgue, Tom Lendacky,
Siva Reddy Kallam, Prashant Sreedharan, Michael Chan, Fugang Duan,
Pantelis Antoniou, Vitaly Bordug, Jose Abreu, Larry Finger,
Florian Schilhabel, Greg Kroah-Hartman, Thomas Gleixner,
linux-kernel, linux-crypto, linux-arm-kernel, netdev,
linuxppc-dev, devel
In-Reply-To: <20180717160541.3843-1-krzk@kernel.org>
On Tue, Jul 17, 2018 at 06:05:35PM +0200, Krzysztof Kozlowski wrote:
> Hi,
>
> Kernel defines same polynomial for CRC-32 in few places.
> This is unnecessary duplication of the same value. Also this might
> be error-prone for future code - every driver will define the
> polynomial again.
>
> This is an attempt to unify definition of polynomial. Few obvious
> hard-coded locations are fixed with define.
>
> All series depend on each 1/6 and 2/6.
>
> This could be merged in two different merge windows (1st lib/crc and then
> the rest) or taken through one tree.
>
> It would be nice to get some testing. Only generic lib/crc, bunzip, xz_crc32
> and Freescale's Ethernet driver were tested on HW. Rest got just different
> builds.
>
> Best regards,
> Krzysztof
>
>
>
>
> Krzysztof Kozlowski (6):
> lib/crc: Move polynomial definition to separate header
> lib/crc: Use consistent naming for CRC-32 polynomials
> crypto: stm32_crc32 - Use existing define with polynomial
> net: ethernet: Use existing define with polynomial
> staging: rtl: Use existing define with polynomial
> lib: Use existing define with polynomial
>
> drivers/crypto/stm32/stm32_crc32.c | 11 ++++-------
> drivers/net/ethernet/amd/xgbe/xgbe-dev.c | 4 ++--
> drivers/net/ethernet/apple/bmac.c | 8 ++------
> drivers/net/ethernet/broadcom/tg3.c | 3 ++-
> drivers/net/ethernet/freescale/fec_main.c | 4 ++--
> drivers/net/ethernet/freescale/fs_enet/fec.h | 3 ---
> drivers/net/ethernet/freescale/fs_enet/mac-fec.c | 3 ++-
> drivers/net/ethernet/micrel/ks8851_mll.c | 3 ++-
> drivers/net/ethernet/synopsys/dwc-xlgmac-hw.c | 4 ++--
> drivers/staging/rtl8712/rtl871x_security.c | 5 ++---
> drivers/staging/rtl8723bs/core/rtw_security.c | 5 ++---
> include/linux/crc32poly.h | 20 ++++++++++++++++++++
> lib/crc32.c | 11 ++++++-----
> lib/crc32defs.h | 14 --------------
> lib/decompress_bunzip2.c | 3 ++-
> lib/gen_crc32table.c | 5 +++--
> lib/xz/xz_crc32.c | 3 ++-
> 17 files changed, 55 insertions(+), 54 deletions(-)
> create mode 100644 include/linux/crc32poly.h
All applied. Thanks.
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply
* Re: [PATCH resend] powerpc/64s: fix page table fragment refcount race vs speculative references
From: Nicholas Piggin @ 2018-07-27 16:32 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linuxppc-dev, Andrew Morton, Linus Torvalds, Aneesh Kumar K . V,
linux-mm
In-Reply-To: <20180727153834.GC13348@bombadil.infradead.org>
On Fri, 27 Jul 2018 08:38:35 -0700
Matthew Wilcox <willy@infradead.org> wrote:
> On Sat, Jul 28, 2018 at 12:29:06AM +1000, Nicholas Piggin wrote:
> > On Fri, 27 Jul 2018 06:41:56 -0700
> > Matthew Wilcox <willy@infradead.org> wrote:
> >
> > > On Fri, Jul 27, 2018 at 09:48:17PM +1000, Nicholas Piggin wrote:
> > > > The page table fragment allocator uses the main page refcount racily
> > > > with respect to speculative references. A customer observed a BUG due
> > > > to page table page refcount underflow in the fragment allocator. This
> > > > can be caused by the fragment allocator set_page_count stomping on a
> > > > speculative reference, and then the speculative failure handler
> > > > decrements the new reference, and the underflow eventually pops when
> > > > the page tables are freed.
> > >
> > > Oof. Can't you fix this instead by using page_ref_add() instead of
> > > set_page_count()?
> >
> > It's ugly doing it that way. The problem is we have a page table
> > destructor and that would be missed if the spec ref was the last
> > put. In practice with RCU page table freeing maybe you can say
> > there will be no spec ref there (unless something changes), but
> > still it just seems much simpler doing this and avoiding any
> > complexity or relying on other synchronization.
>
> I don't want to rely on the speculative reference not happening by the
> time the page table is torn down; that's way too black-magic for me.
> Another possibility would be to use, say, the top 16 bits of the
> atomic for your counter and call the dtor once the atomic is below 64k.
> I'm also thinking about overhauling the dtor system so it's not tied to
> compound pages; anyone with a bit in page_type would be able to use it.
> That way you'd always get your dtor called, even if the speculative
> reference was the last one.
Yeah we could look at doing either of those if necessary.
>
> > > > Any objection to the struct page change to grab the arch specific
> > > > page table page word for powerpc to use? If not, then this should
> > > > go via powerpc tree because it's inconsequential for core mm.
> > >
> > > I want (eventually) to get to the point where every struct page carries
> > > a pointer to the struct mm that it belongs to. It's good for debugging
> > > as well as handling memory errors in page tables.
> >
> > That doesn't seem like it should be a problem, there's some spare
> > words there for arch independent users.
>
> Could you take one of the spare words instead then? My intent was to
> just take the 'x86 pgds only' comment off that member. _pt_pad_2 looks
> ideal because it'll be initialised to 0 and you'll return it to 0 by
> the time you're done.
It doesn't matter for powerpc where the atomic_t goes, so I'm fine with
moving it. But could you juggle the fields with your patch instead? I
thought it would be nice to using this field that has been already
tested on x86 not to overlap with any other data for
bug fix that'll have to be widely backported.
Thanks,
Nick
^ permalink raw reply
* Re: [PATCH v2 04/10] powerpc/traps: Use REG_FMT in show_signal_msg()
From: LEROY Christophe @ 2018-07-27 16:40 UTC (permalink / raw)
To: Murilo Opsfelder Araujo
Cc: linuxppc-dev, Tobin C . Harding, Sukadev Bhattiprolu, Simon Guo,
Paul Mackerras, Nicholas Piggin, Michael Neuling,
Michael Ellerman, Eric W . Biederman, Cyril Bur,
Benjamin Herrenschmidt, Balbir Singh, Andrew Donnellan,
Alastair D'Silva, linux-kernel
In-Reply-To: <20180727145811.12334-5-muriloo@linux.ibm.com>
Murilo Opsfelder Araujo <muriloo@linux.ibm.com> a =C3=A9crit=C2=A0:
> Simplify the message format by using REG_FMT as the register format. Thi=
s
> avoids having two different formats and avoids checking for MSR_64BIT.
Are you sure it is what we want ?
Won't it change the behaviour for a 32 bits app running on a 64bits kernel =
?
Christophe
>
> Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
> ---
> arch/powerpc/kernel/traps.c | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 4faab4705774..047d980ac776 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -311,17 +311,13 @@ static bool show_unhandled_signals_ratelimited(void=
)
> static void show_signal_msg(int signr, struct pt_regs *regs, int code,
> unsigned long addr)
> {
> - const char fmt32[] =3D KERN_INFO "%s[%d]: unhandled signal %d " \
> - "at %08lx nip %08lx lr %08lx code %x\n";
> - const char fmt64[] =3D KERN_INFO "%s[%d]: unhandled signal %d " \
> - "at %016lx nip %016lx lr %016lx code %x\n";
> -
> if (!unhandled_signal(current, signr))
> return;
>
> - printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
> - current->comm, current->pid, signr,
> - addr, regs->nip, regs->link, code);
> + pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
> + " nip "REG_FMT" lr "REG_FMT" code %x\n",
> + current->comm, current->pid, signr, addr,
> + regs->nip, regs->link, code);
> }
>
> void _exception_pkey(int signr, struct pt_regs *regs, int code,
> --
> 2.17.1
^ permalink raw reply
* Re: [PATCH] of/fdt: Remove PPC32 longtrail hack in memory scan
From: Rob Herring @ 2018-07-27 17:12 UTC (permalink / raw)
To: Michael Ellerman; +Cc: devicetree, Frank Rowand, Paul Mackerras, linuxppc-dev
In-Reply-To: <20180727053555.26596-1-mpe@ellerman.id.au>
On Thu, Jul 26, 2018 at 11:36 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> When the OF code was originally made common by Grant in commit
> 51975db0b733 ("of/flattree: merge early_init_dt_scan_memory() common
> code") (Feb 2010), the common code inherited a hack to handle
> PPC "longtrail" machines, which had a "memory@0" node with no
> device_type.
>
> That check was then made to only apply to PPC32 in b44aa25d20e2 ("of:
> Handle memory@0 node on PPC32 only") (May 2014).
>
> But according to Paul Mackerras the "longtrail" machines are long
> dead, if they were ever seen in the wild at all. If someone does still
> have one, we can handle this firmware wart in powerpc platform code.
>
> So remove the hack once and for all.
Yay. I guess Power Macs and other quirks will never die...
I'll queue this up.
Rob
^ permalink raw reply
* Re: [PATCH v2 04/10] powerpc/traps: Use REG_FMT in show_signal_msg()
From: Joe Perches @ 2018-07-27 17:18 UTC (permalink / raw)
To: LEROY Christophe, Murilo Opsfelder Araujo
Cc: linuxppc-dev, Tobin C . Harding, Sukadev Bhattiprolu, Simon Guo,
Paul Mackerras, Nicholas Piggin, Michael Neuling,
Michael Ellerman, Eric W . Biederman, Cyril Bur,
Benjamin Herrenschmidt, Balbir Singh, Andrew Donnellan,
Alastair D'Silva, linux-kernel
In-Reply-To: <20180727184023.Horde.KRXPzZpG18uxt_B9sy_FBg5@messagerie.si.c-s.fr>
On Fri, 2018-07-27 at 18:40 +0200, LEROY Christophe wrote:
> Murilo Opsfelder Araujo <muriloo@linux.ibm.com> a écrit :
>
> > Simplify the message format by using REG_FMT as the register format. This
> > avoids having two different formats and avoids checking for MSR_64BIT.
>
> Are you sure it is what we want ?
>
> Won't it change the behaviour for a 32 bits app running on a 64bits kernel ?
[]
> > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
[]
> > @@ -311,17 +311,13 @@ static bool show_unhandled_signals_ratelimited(void)
> > static void show_signal_msg(int signr, struct pt_regs *regs, int code,
> > unsigned long addr)
> > {
> > - const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
> > - "at %08lx nip %08lx lr %08lx code %x\n";
> > - const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
> > - "at %016lx nip %016lx lr %016lx code %x\n";
> > -
> > if (!unhandled_signal(current, signr))
> > return;
> >
> > - printk(regs->msr & MSR_64BIT ? fmt64 : fmt32,
> > - current->comm, current->pid, signr,
> > - addr, regs->nip, regs->link, code);
> > + pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
I think it better to use a space after the close "
and also the line continuation is unnecessary.
> > + " nip "REG_FMT" lr "REG_FMT" code %x\n",
And spaces before the open quotes too.
I'd also prefer the format on a single line:
pr_info("%s[%d]: unhandled signal %d at " REG_FMT " nip " REG_FMT " lr " REG_FMT " code %x\n",
> > + current->comm, current->pid, signr, addr,
> > + regs->nip, regs->link, code);
Seeing as these are all unsigned long, a better way to do
this is to use %p and cast to pointer.
This might be better anyway as this output exposes pointer
addresses and instead would now use pointer hashed output.
pr_info("%s[%d]: unhandled signal %d at %p nip %p lr %p code %x\n",
current->comm, current->pid, signr,
(void *)addr, (void *)regs->nip, (void *)regs->link, code);
Use %px if you _really_ need to emit unhashed addresses.
see: Documentation/core-api/printk-formats.rst
^ permalink raw reply
* Re: Infinite looping observed in __offline_pages
From: John Allen @ 2018-07-27 17:32 UTC (permalink / raw)
To: Michal Hocko
Cc: linux-kernel, linuxppc-dev, kamezawa.hiroyu, n-horiguchi, mgorman,
nfont
In-Reply-To: <20180725200336.GP28386@dhcp22.suse.cz>
On Wed, Jul 25, 2018 at 10:03:36PM +0200, Michal Hocko wrote:
>On Wed 25-07-18 13:11:15, John Allen wrote:
>[...]
>> Does a failure in do_migrate_range indicate that the range is unmigratable
>> and the loop in __offline_pages should terminate and goto failed_removal? Or
>> should we allow a certain number of retrys before we
>> give up on migrating the range?
>
>Unfortunatelly not. Migration code doesn't tell a difference between
>ephemeral and permanent failures. We are relying on
>start_isolate_page_range to tell us this. So the question is, what kind
>of page is not migratable and for what reason.
>
>Are you able to add some debugging to give us more information. The
>current debugging code in the hotplug/migration sucks...
After reproducing the problem a couple times, it seems that it can occur
for different types of pages. Running page-types on the offending page
over two separate instances produced the following:
# tools/vm/page-types -a 307968-308224
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000400 1 0 __________B________________________________ buddy
total 1 0
And the following on a separate run:
# tools/vm/page-types -a 313088-313344
flags page-count MB symbolic-flags long-symbolic-flags
0x000000000000006c 1 0 __RU_lA____________________________________ referenced,uptodate,lru,active
total 1 0
The source of the failure in migrate_pages actually doesn't seem to be
that we're hitting the case of the permanent failure, but instead the
-EAGAIN case. I traced the EAGAIN return back to
migrate_page_move_mapping which I've seen return EAGAIN in two places:
mm/migrate.c:453
if (!mapping) {
/* Anonymous page without mapping */
if (page_count(page) != expected_count)
return -EAGAIN;
mm/migrate.c:476
if (page_count(page) != expected_count ||
radix_tree_deref_slot_protected(pslot,
&mapping->i_pages.xa_lock) != page) {
xa_unlock_irq(&mapping->i_pages);
return -EAGAIN;
}
So it seems in each case, the actual reference count for the page is not
what it is expected to be.
^ permalink raw reply
* Re: [PATCH v3] PCI: Data corruption happening due to race condition
From: Bjorn Helgaas @ 2018-07-27 22:25 UTC (permalink / raw)
To: Benjamin Herrenschmidt
Cc: Hari Vyas, bhelgaas, linux-pci, ray.jui, Paul Mackerras,
Michael Ellerman, linuxppc-dev
In-Reply-To: <65dd986d0b8b2ebe5132b365dabb2dbaaed9177f.camel@kernel.crashing.org>
On Thu, Jul 19, 2018 at 02:18:09PM +1000, Benjamin Herrenschmidt wrote:
> On Wed, 2018-07-18 at 18:29 -0500, Bjorn Helgaas wrote:
> > [+cc Paul, Michael, linuxppc-dev]
> >
>
> ..../...
>
> > > Debugging revealed a race condition between pcie core driver
> > > enabling is_added bit(pci_bus_add_device()) and nvme driver
> > > reset work-queue enabling is_busmaster bit (by pci_set_master()).
> > > As both fields are not handled in atomic manner and that clears
> > > is_added bit.
> > >
> > > Fix moves device addition is_added bit to separate private flag
> > > variable and use different atomic functions to set and retrieve
> > > device addition state. As is_added shares different memory
> > > location so race condition is avoided.
> >
> > Really nice bit of debugging!
>
> Indeed. However I'm not fan of the solution. Shouldn't we instead have
> some locking for the content of pci_dev ? I've always been wary of us
> having other similar races in there.
>
> As for the powerpc bits, I'm probably the one who wrote them, however,
> I'm on vacation this week and right now, no bandwidth to context switch
> all that back in :-) So give me a few days and/or ping me next week.
OK, here's a ping :)
Some powerpc cleanup would be ideal, but I'd like to fix the race for
v4.19, so I'm fine with this patch as-is. But I'd definitely want
your ack before inserting the ugly #include path in the powerpc code.
> The powerpc PCI code contains a lot of cruft coming from the depth of
> history, including rather nasty assumptions. We want to progressively
> clean it up, starting with EEH, but it will take time.
>
> Cheers,
> Ben.
>
> > > Signed-off-by: Hari Vyas <hari.vyas@broadcom.com>
> > > ---
> > > arch/powerpc/kernel/pci-common.c | 4 +++-
> > > arch/powerpc/platforms/powernv/pci-ioda.c | 3 ++-
> > > arch/powerpc/platforms/pseries/setup.c | 3 ++-
> > > drivers/pci/bus.c | 6 +++---
> > > drivers/pci/hotplug/acpiphp_glue.c | 2 +-
> > > drivers/pci/pci.h | 11 +++++++++++
> > > drivers/pci/probe.c | 4 ++--
> > > drivers/pci/remove.c | 5 +++--
> > > include/linux/pci.h | 1 -
> > > 9 files changed, 27 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> > > index fe9733f..471aac3 100644
> > > --- a/arch/powerpc/kernel/pci-common.c
> > > +++ b/arch/powerpc/kernel/pci-common.c
> > > @@ -42,6 +42,8 @@
> > > #include <asm/ppc-pci.h>
> > > #include <asm/eeh.h>
> > >
> > > +#include "../../../drivers/pci/pci.h"
> >
> > I see why you need it, but this include path is really ugly. Outside
> > of bootloaders and tools, there are very few instances of includes
> > like this that reference a different top-level directory, and I'm not
> > very keen about adding more.
^ permalink raw reply
* [PATCH v5 0/8] powerpc/fsl: Speculation barrier for NXP PowerPC Book3E
From: Michael Ellerman @ 2018-07-27 23:06 UTC (permalink / raw)
To: linuxppc-dev, diana.craciun; +Cc: oss, leoyang.li, bharat.bhushan
Implement barrier_nospec for NXP PowerPC Book3E processors.
Hi Diana,
This series interacts with another series of mine, so I wanted to rework it
slightly. Let me know if this looks OK to you.
cheers
Diana Craciun (6):
powerpc/64: Disable the speculation barrier from the command line
powerpc/64: Make stf barrier PPC_BOOK3S_64 specific.
powerpc/64: Make meltdown reporting Book3S 64 specific
powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book3E
powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit
platforms
Documentation: Add nospectre_v1 parameter
Michael Ellerman (2):
powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC
powerpc/64: Call setup_barrier_nospec() from setup_arch()
Documentation/admin-guide/kernel-parameters.txt | 4 +++
arch/powerpc/Kconfig | 7 ++++-
arch/powerpc/include/asm/barrier.h | 12 ++++++---
arch/powerpc/include/asm/setup.h | 6 ++++-
arch/powerpc/kernel/Makefile | 3 ++-
arch/powerpc/kernel/entry_32.S | 10 +++++++
arch/powerpc/kernel/module.c | 4 ++-
arch/powerpc/kernel/security.c | 17 +++++++++++-
arch/powerpc/kernel/setup-common.c | 2 ++
arch/powerpc/kernel/vmlinux.lds.S | 4 ++-
arch/powerpc/lib/feature-fixups.c | 35 ++++++++++++++++++++++++-
arch/powerpc/platforms/powernv/setup.c | 1 -
arch/powerpc/platforms/pseries/setup.c | 1 -
13 files changed, 94 insertions(+), 12 deletions(-)
--
2.14.1
^ permalink raw reply
* [PATCH v5 1/8] powerpc/64: Disable the speculation barrier from the command line
From: Michael Ellerman @ 2018-07-27 23:06 UTC (permalink / raw)
To: linuxppc-dev, diana.craciun; +Cc: oss, leoyang.li, bharat.bhushan
In-Reply-To: <20180727230639.25413-1-mpe@ellerman.id.au>
From: Diana Craciun <diana.craciun@nxp.com>
The speculation barrier can be disabled from the command line
with the parameter: "nospectre_v1".
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/kernel/security.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
v5: No change.
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 4cb8f1f7b593..79f9397998ed 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -16,6 +16,7 @@
unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
bool barrier_nospec_enabled;
+static bool no_nospec;
static void enable_barrier_nospec(bool enable)
{
@@ -42,9 +43,18 @@ void setup_barrier_nospec(void)
enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR);
- enable_barrier_nospec(enable);
+ if (!no_nospec)
+ enable_barrier_nospec(enable);
}
+static int __init handle_nospectre_v1(char *p)
+{
+ no_nospec = true;
+
+ return 0;
+}
+early_param("nospectre_v1", handle_nospectre_v1);
+
#ifdef CONFIG_DEBUG_FS
static int barrier_nospec_set(void *data, u64 val)
{
--
2.14.1
^ permalink raw reply related
* [PATCH v5 2/8] powerpc/64: Make stf barrier PPC_BOOK3S_64 specific.
From: Michael Ellerman @ 2018-07-27 23:06 UTC (permalink / raw)
To: linuxppc-dev, diana.craciun; +Cc: oss, leoyang.li, bharat.bhushan
In-Reply-To: <20180727230639.25413-1-mpe@ellerman.id.au>
From: Diana Craciun <diana.craciun@nxp.com>
NXP Book3E platforms are not vulnerable to speculative store
bypass, so make the mitigations PPC_BOOK3S_64 specific.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/kernel/security.c | 3 +++
1 file changed, 3 insertions(+)
v5: No change.
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 79f9397998ed..77f253a6f8c9 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -176,6 +176,7 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c
return s.len;
}
+#ifdef CONFIG_PPC_BOOK3S_64
/*
* Store-forwarding barrier support.
*/
@@ -323,3 +324,5 @@ static __init int stf_barrier_debugfs_init(void)
}
device_initcall(stf_barrier_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
--
2.14.1
^ permalink raw reply related
* [PATCH v5 3/8] powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC
From: Michael Ellerman @ 2018-07-27 23:06 UTC (permalink / raw)
To: linuxppc-dev, diana.craciun; +Cc: oss, leoyang.li, bharat.bhushan
In-Reply-To: <20180727230639.25413-1-mpe@ellerman.id.au>
Add a config symbol to encode which platforms support the
barrier_nospec speculation barrier. Currently this is just Book3S 64
but we will add Book3E in a future patch.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/Kconfig | 7 ++++++-
arch/powerpc/include/asm/barrier.h | 6 +++---
arch/powerpc/include/asm/setup.h | 2 +-
arch/powerpc/kernel/Makefile | 3 ++-
arch/powerpc/kernel/module.c | 4 +++-
arch/powerpc/kernel/vmlinux.lds.S | 4 +++-
arch/powerpc/lib/feature-fixups.c | 6 ++++--
7 files changed, 22 insertions(+), 10 deletions(-)
v5: Rename the config symbol to match the name of the barrier and the name we
use in the code, ie. BARRIER_NOSPEC.
Don't introduce the freescale code in this patch.
Use BARRIER_NOSPEC in more places.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5eb4d969afbf..aef1c4e049f1 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -165,7 +165,7 @@ config PPC
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
- select GENERIC_CPU_VULNERABILITIES if PPC_BOOK3S_64
+ select GENERIC_CPU_VULNERABILITIES if PPC_BARRIER_NOSPEC
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
select GENERIC_SMP_IDLE_THREAD
@@ -241,6 +241,11 @@ config PPC
# Please keep this list sorted alphabetically.
#
+config PPC_BARRIER_NOSPEC
+ bool
+ default y
+ depends on PPC_BOOK3S_64
+
config GENERIC_CSUM
def_bool n
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index f67b3f6e36be..ec43375463ba 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -76,7 +76,7 @@ do { \
___p1; \
})
-#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
/*
* Prevent execution of subsequent instructions until preceding branches have
* been fully resolved and are no longer executing speculatively.
@@ -86,10 +86,10 @@ do { \
// This also acts as a compiler barrier due to the memory clobber.
#define barrier_nospec() asm (stringify_in_c(barrier_nospec_asm) ::: "memory")
-#else /* !CONFIG_PPC_BOOK3S_64 */
+#else /* !CONFIG_PPC_BARRIER_NOSPEC */
#define barrier_nospec_asm
#define barrier_nospec()
-#endif
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */
#include <asm-generic/barrier.h>
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 8721fd004291..8205f9fdfd67 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -56,7 +56,7 @@ void setup_barrier_nospec(void);
void do_barrier_nospec_fixups(bool enable);
extern bool barrier_nospec_enabled;
-#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
void do_barrier_nospec_fixups_range(bool enable, void *start, void *end);
#else
static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { };
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2b4c40b255e4..dbe2cf04b406 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -42,9 +42,10 @@ obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o
-obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o security.o
+obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o
obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o
obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o
+obj-$(CONFIG_PPC_BARRIER_NOSPEC) += security.o
obj-$(CONFIG_PPC64) += vdso64/
obj-$(CONFIG_ALTIVEC) += vecemu.o
obj-$(CONFIG_PPC_970_NAP) += idle_power4.o
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index 1b3c6835e730..77371c9ef3d8 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -72,13 +72,15 @@ int module_finalize(const Elf_Ehdr *hdr,
do_feature_fixups(powerpc_firmware_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
+#endif /* CONFIG_PPC64 */
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
if (sect != NULL)
do_barrier_nospec_fixups_range(barrier_nospec_enabled,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
-#endif
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */
sect = find_section(hdr, sechdrs, "__lwsync_fixup");
if (sect != NULL)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 5baac79df97e..07ae018e550e 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -153,14 +153,16 @@ SECTIONS
*(__rfi_flush_fixup)
__stop___rfi_flush_fixup = .;
}
+#endif /* CONFIG_PPC64 */
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
. = ALIGN(8);
__spec_barrier_fixup : AT(ADDR(__spec_barrier_fixup) - LOAD_OFFSET) {
__start___barrier_nospec_fixup = .;
*(__barrier_nospec_fixup)
__stop___barrier_nospec_fixup = .;
}
-#endif
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */
EXCEPTION_TABLE(0)
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 8b69f868298c..0e604b41b5d1 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -304,6 +304,9 @@ void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_
printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
void do_barrier_nospec_fixups(bool enable)
{
void *start, *end;
@@ -313,8 +316,7 @@ void do_barrier_nospec_fixups(bool enable)
do_barrier_nospec_fixups_range(enable, start, end);
}
-
-#endif /* CONFIG_PPC_BOOK3S_64 */
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */
void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
--
2.14.1
^ permalink raw reply related
* [PATCH v5 4/8] powerpc/64: Call setup_barrier_nospec() from setup_arch()
From: Michael Ellerman @ 2018-07-27 23:06 UTC (permalink / raw)
To: linuxppc-dev, diana.craciun; +Cc: oss, leoyang.li, bharat.bhushan
In-Reply-To: <20180727230639.25413-1-mpe@ellerman.id.au>
Currently we require platform code to call setup_barrier_nospec(). But
if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case
then we can call it in setup_arch().
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/include/asm/setup.h | 4 ++++
arch/powerpc/kernel/setup-common.c | 2 ++
arch/powerpc/platforms/powernv/setup.c | 1 -
arch/powerpc/platforms/pseries/setup.c | 1 -
4 files changed, 6 insertions(+), 2 deletions(-)
v5: Split out.
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 8205f9fdfd67..1a951b00465d 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -52,7 +52,11 @@ enum l1d_flush_type {
void setup_rfi_flush(enum l1d_flush_type, bool enable);
void do_rfi_flush_fixups(enum l1d_flush_type types);
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
void setup_barrier_nospec(void);
+#else
+static inline void setup_barrier_nospec(void) { };
+#endif
void do_barrier_nospec_fixups(bool enable);
extern bool barrier_nospec_enabled;
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 40b44bb53a4e..93fa0c99681e 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -972,6 +972,8 @@ void __init setup_arch(char **cmdline_p)
if (ppc_md.setup_arch)
ppc_md.setup_arch();
+ setup_barrier_nospec();
+
paging_init();
/* Initialize the MMU context management stuff. */
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index f96df0a25d05..1ab6dc70b5a4 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -124,7 +124,6 @@ static void pnv_setup_rfi_flush(void)
security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
setup_rfi_flush(type, enable);
- setup_barrier_nospec();
}
static void __init pnv_setup_arch(void)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 139f0af6c3d9..fdb32e056ef4 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -534,7 +534,6 @@ void pseries_setup_rfi_flush(void)
security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR);
setup_rfi_flush(types, enable);
- setup_barrier_nospec();
}
#ifdef CONFIG_PCI_IOV
--
2.14.1
^ permalink raw reply related
* [PATCH v5 5/8] powerpc/64: Make meltdown reporting Book3S 64 specific
From: Michael Ellerman @ 2018-07-27 23:06 UTC (permalink / raw)
To: linuxppc-dev, diana.craciun; +Cc: oss, leoyang.li, bharat.bhushan
In-Reply-To: <20180727230639.25413-1-mpe@ellerman.id.au>
From: Diana Craciun <diana.craciun@nxp.com>
In a subsequent patch we will enable building security.c for Book3E.
However the NXP platforms are not vulnerable to Meltdown, so make the
Meltdown vulnerability reporting PPC_BOOK3S_64 specific.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/kernel/security.c | 2 ++
1 file changed, 2 insertions(+)
v5: Split out.
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 77f253a6f8c9..ef72161de474 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -92,6 +92,7 @@ static __init int barrier_nospec_debugfs_init(void)
device_initcall(barrier_nospec_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
+#ifdef CONFIG_PPC_BOOK3S_64
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
bool thread_priv;
@@ -124,6 +125,7 @@ ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, cha
return sprintf(buf, "Vulnerable\n");
}
+#endif
ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
{
--
2.14.1
^ permalink raw reply related
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