* [PATCH 0/3] x86/mce: Fix more noinstr fun
@ 2022-02-04 8:30 Borislav Petkov
2022-02-04 8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
` (3 more replies)
0 siblings, 4 replies; 11+ messages in thread
From: Borislav Petkov @ 2022-02-04 8:30 UTC (permalink / raw)
To: Tony Luck; +Cc: Jakub Kicinski, Linus Torvalds, Marco Elver, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
Hi all,
here's a second small set of fixes for objtool noinstr validation issues
in the MCE code.
It goes ontop of tip:locking/core where there are some more commits
changing generic helpers to be always inlined.
As always, comments and suggestions are appreciated.
Thx.
Borislav Petkov (3):
cpumask: Add a x86-specific cpumask_clear_cpu() helper
x86/ptrace: Always inline v8086_mode() for instrumentation
x86/mce: Use arch atomic and bit helpers
arch/x86/include/asm/cpumask.h | 10 ++++++
arch/x86/include/asm/ptrace.h | 2 +-
arch/x86/kernel/cpu/mce/core.c | 58 ++++++++++--------------------
arch/x86/kernel/cpu/mce/internal.h | 23 ++++++++++--
arch/x86/kernel/cpu/mce/severity.c | 2 +-
include/linux/cpumask.h | 4 +--
6 files changed, 54 insertions(+), 45 deletions(-)
--
2.29.2
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper
2022-02-04 8:30 [PATCH 0/3] x86/mce: Fix more noinstr fun Borislav Petkov
@ 2022-02-04 8:30 ` Borislav Petkov
2022-02-04 16:46 ` Luck, Tony
2022-02-13 10:59 ` [tip: locking/core] " tip-bot2 for Borislav Petkov
2022-02-04 8:30 ` [PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation Borislav Petkov
` (2 subsequent siblings)
3 siblings, 2 replies; 11+ messages in thread
From: Borislav Petkov @ 2022-02-04 8:30 UTC (permalink / raw)
To: Tony Luck; +Cc: Jakub Kicinski, Linus Torvalds, Marco Elver, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
Add a x86-specific cpumask_clear_cpu() helper which will be used in
places where the explicit KASAN-instrumentation in the *_bit() helpers
is unwanted.
Also, always inline two more cpumask generic helpers.
allyesconfig:
text data bss dec hex filename
190553143 159425889 32076404 382055436 16c5b40c vmlinux.before
190551812 159424945 32076404 382053161 16c5ab29 vmlinux.after
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/include/asm/cpumask.h | 10 ++++++++++
include/linux/cpumask.h | 4 ++--
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/cpumask.h b/arch/x86/include/asm/cpumask.h
index 3afa990d756b..c5aed9e9226c 100644
--- a/arch/x86/include/asm/cpumask.h
+++ b/arch/x86/include/asm/cpumask.h
@@ -20,11 +20,21 @@ static __always_inline bool arch_cpu_online(int cpu)
{
return arch_test_bit(cpu, cpumask_bits(cpu_online_mask));
}
+
+static __always_inline void arch_cpumask_clear_cpu(int cpu, struct cpumask *dstp)
+{
+ arch_clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
+}
#else
static __always_inline bool arch_cpu_online(int cpu)
{
return cpu == 0;
}
+
+static __always_inline void arch_cpumask_clear_cpu(int cpu, struct cpumask *dstp)
+{
+ return;
+}
#endif
#define arch_cpu_is_offline(cpu) unlikely(!arch_cpu_online(cpu))
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 6b06c698cd2a..fe29ac7cc469 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -102,7 +102,7 @@ extern atomic_t __num_online_cpus;
extern cpumask_t cpus_booted_once_mask;
-static inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
+static __always_inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
{
#ifdef CONFIG_DEBUG_PER_CPU_MAPS
WARN_ON_ONCE(cpu >= bits);
@@ -110,7 +110,7 @@ static inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
}
/* verify cpu argument to cpumask_* operators */
-static inline unsigned int cpumask_check(unsigned int cpu)
+static __always_inline unsigned int cpumask_check(unsigned int cpu)
{
cpu_max_bits_warn(cpu, nr_cpumask_bits);
return cpu;
--
2.29.2
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation
2022-02-04 8:30 [PATCH 0/3] x86/mce: Fix more noinstr fun Borislav Petkov
2022-02-04 8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
@ 2022-02-04 8:30 ` Borislav Petkov
2022-02-13 10:59 ` [tip: locking/core] " tip-bot2 for Borislav Petkov
2022-02-04 8:30 ` [PATCH 3/3] x86/mce: Use arch atomic and bit helpers Borislav Petkov
2022-02-04 11:24 ` [PATCH 0/3] x86/mce: Fix more noinstr fun Marco Elver
3 siblings, 1 reply; 11+ messages in thread
From: Borislav Petkov @ 2022-02-04 8:30 UTC (permalink / raw)
To: Tony Luck; +Cc: Jakub Kicinski, Linus Torvalds, Marco Elver, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
Instrumentation glue like KASAN causes the following warning:
vmlinux.o: warning: objtool: mce_gather_info()+0x5f: call to v8086_mode.constprop.0() leaves .noinstr.text section
due to gcc creating a function call for that oneliner. Force-inline it
and even save some vmlinux bytes (.config is close to an allmodconfig):
text data bss dec hex filename
209431677 208257651 34411048 452100376 1af28118 vmlinux.before
209431519 208257615 34411048 452100182 1af28056 vmlinux.after
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/include/asm/ptrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 703663175a5a..4357e0f2cd5f 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -137,7 +137,7 @@ static __always_inline int user_mode(struct pt_regs *regs)
#endif
}
-static inline int v8086_mode(struct pt_regs *regs)
+static __always_inline int v8086_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_32
return (regs->flags & X86_VM_MASK);
--
2.29.2
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 3/3] x86/mce: Use arch atomic and bit helpers
2022-02-04 8:30 [PATCH 0/3] x86/mce: Fix more noinstr fun Borislav Petkov
2022-02-04 8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
2022-02-04 8:30 ` [PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation Borislav Petkov
@ 2022-02-04 8:30 ` Borislav Petkov
2022-02-14 10:03 ` [tip: ras/core] " tip-bot2 for Borislav Petkov
2022-02-04 11:24 ` [PATCH 0/3] x86/mce: Fix more noinstr fun Marco Elver
3 siblings, 1 reply; 11+ messages in thread
From: Borislav Petkov @ 2022-02-04 8:30 UTC (permalink / raw)
To: Tony Luck; +Cc: Jakub Kicinski, Linus Torvalds, Marco Elver, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
The arch helpers do not have explicit KASAN instrumentation. Use them in
noinstr code.
Inline a couple more functions with single call sites, while at it:
mce_severity_amd_smca() has a single call-site which is noinstr so force
the inlining and fix:
vmlinux.o: warning: objtool: mce_severity_amd.constprop.0()+0xca: call to \
mce_severity_amd_smca() leaves .noinstr.text section
Always inline mca_msr_reg():
text data bss dec hex filename
16065240 128031326 36405368 180501934 ac23dae vmlinux.before
16065240 128031294 36405368 180501902 ac23d8e vmlinux.after
and mce_no_way_out() as the latter one is used only once, to fix:
vmlinux.o: warning: objtool: mce_read_aux()+0x53: call to mca_msr_reg() leaves .noinstr.text section
vmlinux.o: warning: objtool: do_machine_check()+0xc9: call to mce_no_way_out() leaves .noinstr.text section
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/mce/core.c | 58 ++++++++++--------------------
arch/x86/kernel/cpu/mce/internal.h | 23 ++++++++++--
arch/x86/kernel/cpu/mce/severity.c | 2 +-
3 files changed, 41 insertions(+), 42 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 5818b837fd4d..0e7147430ec0 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -173,27 +173,6 @@ void mce_unregister_decode_chain(struct notifier_block *nb)
}
EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
-u32 mca_msr_reg(int bank, enum mca_msr reg)
-{
- if (mce_flags.smca) {
- switch (reg) {
- case MCA_CTL: return MSR_AMD64_SMCA_MCx_CTL(bank);
- case MCA_ADDR: return MSR_AMD64_SMCA_MCx_ADDR(bank);
- case MCA_MISC: return MSR_AMD64_SMCA_MCx_MISC(bank);
- case MCA_STATUS: return MSR_AMD64_SMCA_MCx_STATUS(bank);
- }
- }
-
- switch (reg) {
- case MCA_CTL: return MSR_IA32_MCx_CTL(bank);
- case MCA_ADDR: return MSR_IA32_MCx_ADDR(bank);
- case MCA_MISC: return MSR_IA32_MCx_MISC(bank);
- case MCA_STATUS: return MSR_IA32_MCx_STATUS(bank);
- }
-
- return 0;
-}
-
static void __print_mce(struct mce *m)
{
pr_emerg(HW_ERR "CPU %d: Machine Check%s: %Lx Bank %d: %016Lx\n",
@@ -814,7 +793,8 @@ EXPORT_SYMBOL_GPL(machine_check_poll);
* the severity assessment code. Pretend that EIPV was set, and take the
* ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
*/
-static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
+static __always_inline void
+quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
{
if (bank != 0)
return;
@@ -838,8 +818,8 @@ static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
* Do a quick check if any of the events requires a panic.
* This decides if we keep the events around or clear them.
*/
-static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
- struct pt_regs *regs)
+static __always_inline int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
+ struct pt_regs *regs)
{
char *tmp = *msg;
int i;
@@ -849,7 +829,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
if (!(m->status & MCI_STATUS_VAL))
continue;
- __set_bit(i, validp);
+ arch___set_bit(i, validp);
if (mce_flags.snb_ifu_quirk)
quirk_sandybridge_ifu(i, m, regs);
@@ -1015,13 +995,13 @@ static noinstr int mce_start(int *no_way_out)
if (!timeout)
return ret;
- atomic_add(*no_way_out, &global_nwo);
+ arch_atomic_add(*no_way_out, &global_nwo);
/*
* Rely on the implied barrier below, such that global_nwo
* is updated before mce_callin.
*/
- order = atomic_inc_return(&mce_callin);
- cpumask_clear_cpu(smp_processor_id(), &mce_missing_cpus);
+ order = arch_atomic_inc_return(&mce_callin);
+ arch_cpumask_clear_cpu(smp_processor_id(), &mce_missing_cpus);
/* Enable instrumentation around calls to external facilities */
instrumentation_begin();
@@ -1029,10 +1009,10 @@ static noinstr int mce_start(int *no_way_out)
/*
* Wait for everyone.
*/
- while (atomic_read(&mce_callin) != num_online_cpus()) {
+ while (arch_atomic_read(&mce_callin) != num_online_cpus()) {
if (mce_timed_out(&timeout,
"Timeout: Not all CPUs entered broadcast exception handler")) {
- atomic_set(&global_nwo, 0);
+ arch_atomic_set(&global_nwo, 0);
goto out;
}
ndelay(SPINUNIT);
@@ -1047,7 +1027,7 @@ static noinstr int mce_start(int *no_way_out)
/*
* Monarch: Starts executing now, the others wait.
*/
- atomic_set(&mce_executing, 1);
+ arch_atomic_set(&mce_executing, 1);
} else {
/*
* Subject: Now start the scanning loop one by one in
@@ -1055,10 +1035,10 @@ static noinstr int mce_start(int *no_way_out)
* This way when there are any shared banks it will be
* only seen by one CPU before cleared, avoiding duplicates.
*/
- while (atomic_read(&mce_executing) < order) {
+ while (arch_atomic_read(&mce_executing) < order) {
if (mce_timed_out(&timeout,
"Timeout: Subject CPUs unable to finish machine check processing")) {
- atomic_set(&global_nwo, 0);
+ arch_atomic_set(&global_nwo, 0);
goto out;
}
ndelay(SPINUNIT);
@@ -1068,7 +1048,7 @@ static noinstr int mce_start(int *no_way_out)
/*
* Cache the global no_way_out state.
*/
- *no_way_out = atomic_read(&global_nwo);
+ *no_way_out = arch_atomic_read(&global_nwo);
ret = order;
@@ -1153,12 +1133,12 @@ static noinstr int mce_end(int order)
return ret;
}
-static void mce_clear_state(unsigned long *toclear)
+static __always_inline void mce_clear_state(unsigned long *toclear)
{
int i;
for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
- if (test_bit(i, toclear))
+ if (arch_test_bit(i, toclear))
mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
}
}
@@ -1208,8 +1188,8 @@ __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final,
int severity, i, taint = 0;
for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
- __clear_bit(i, toclear);
- if (!test_bit(i, valid_banks))
+ arch___clear_bit(i, toclear);
+ if (!arch_test_bit(i, valid_banks))
continue;
if (!mce_banks[i].ctl)
@@ -1244,7 +1224,7 @@ __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final,
severity == MCE_UCNA_SEVERITY) && !no_way_out)
continue;
- __set_bit(i, toclear);
+ arch___set_bit(i, toclear);
/* Machine check event was not enabled. Clear, but ignore. */
if (severity == MCE_NO_SEVERITY)
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 52c633950b38..a04b61e27827 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -182,8 +182,6 @@ enum mca_msr {
MCA_MISC,
};
-u32 mca_msr_reg(int bank, enum mca_msr reg);
-
/* Decide whether to add MCE record to MCE event pool or filter it out. */
extern bool filter_mce(struct mce *m);
@@ -209,4 +207,25 @@ static inline void winchip_machine_check(struct pt_regs *regs) {}
noinstr u64 mce_rdmsrl(u32 msr);
+static __always_inline u32 mca_msr_reg(int bank, enum mca_msr reg)
+{
+ if (mce_flags.smca) {
+ switch (reg) {
+ case MCA_CTL: return MSR_AMD64_SMCA_MCx_CTL(bank);
+ case MCA_ADDR: return MSR_AMD64_SMCA_MCx_ADDR(bank);
+ case MCA_MISC: return MSR_AMD64_SMCA_MCx_MISC(bank);
+ case MCA_STATUS: return MSR_AMD64_SMCA_MCx_STATUS(bank);
+ }
+ }
+
+ switch (reg) {
+ case MCA_CTL: return MSR_IA32_MCx_CTL(bank);
+ case MCA_ADDR: return MSR_IA32_MCx_ADDR(bank);
+ case MCA_MISC: return MSR_IA32_MCx_MISC(bank);
+ case MCA_STATUS: return MSR_IA32_MCx_STATUS(bank);
+ }
+
+ return 0;
+}
+
#endif /* __X86_MCE_INTERNAL_H__ */
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index 7aa2bda93cbb..ca0d775346fb 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -301,7 +301,7 @@ static noinstr int error_context(struct mce *m, struct pt_regs *regs)
}
}
-static int mce_severity_amd_smca(struct mce *m, enum context err_ctx)
+static __always_inline int mce_severity_amd_smca(struct mce *m, enum context err_ctx)
{
u64 mcx_cfg;
--
2.29.2
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 0/3] x86/mce: Fix more noinstr fun
2022-02-04 8:30 [PATCH 0/3] x86/mce: Fix more noinstr fun Borislav Petkov
` (2 preceding siblings ...)
2022-02-04 8:30 ` [PATCH 3/3] x86/mce: Use arch atomic and bit helpers Borislav Petkov
@ 2022-02-04 11:24 ` Marco Elver
2022-02-04 14:48 ` Borislav Petkov
3 siblings, 1 reply; 11+ messages in thread
From: Marco Elver @ 2022-02-04 11:24 UTC (permalink / raw)
To: Borislav Petkov; +Cc: Tony Luck, Jakub Kicinski, Linus Torvalds, X86 ML, LKML
On Fri, 4 Feb 2022 at 09:30, Borislav Petkov <bp@alien8.de> wrote:
>
> From: Borislav Petkov <bp@suse.de>
>
> Hi all,
>
> here's a second small set of fixes for objtool noinstr validation issues
> in the MCE code.
>
> It goes ontop of tip:locking/core where there are some more commits
> changing generic helpers to be always inlined.
>
> As always, comments and suggestions are appreciated.
>
> Thx.
>
> Borislav Petkov (3):
> cpumask: Add a x86-specific cpumask_clear_cpu() helper
> x86/ptrace: Always inline v8086_mode() for instrumentation
> x86/mce: Use arch atomic and bit helpers
I guess to solve noinstr "calling" something else the only solution is
to make the other function noinstr as well, or __always_inline.
Have you considered making some of these other functions 'noinstr' as
well? I guess __always_inline works, esp. if there's just 1 caller.
And by the looks of it you're getting a net .text reduction, so
Acked-by: Marco Elver <elver@google.com>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 0/3] x86/mce: Fix more noinstr fun
2022-02-04 11:24 ` [PATCH 0/3] x86/mce: Fix more noinstr fun Marco Elver
@ 2022-02-04 14:48 ` Borislav Petkov
0 siblings, 0 replies; 11+ messages in thread
From: Borislav Petkov @ 2022-02-04 14:48 UTC (permalink / raw)
To: Marco Elver; +Cc: Tony Luck, Jakub Kicinski, Linus Torvalds, X86 ML, LKML
On Fri, Feb 04, 2022 at 12:24:00PM +0100, Marco Elver wrote:
> I guess to solve noinstr "calling" something else the only solution is
> to make the other function noinstr as well, or __always_inline.
>
> Have you considered making some of these other functions 'noinstr' as
> well? I guess __always_inline works, esp. if there's just 1 caller.
> And by the looks of it you're getting a net .text reduction, so
Yeah, I started doing that and the savings were the persuasive
argument.
Even more so if the function has one caller only and gets inlined,
normally. I guess it doesn't get inlined when there's KASAN
instrumentation or so but I haven't verified it fully why.
Because even for oneliners like v8086_mode() which should get inlined
trivially, the compiler ends up doing this constprop thing - I guess
some constants folding optimization thing... it probably doesn't even
matter so much whether oneliners get inlined in KASAN-enabled builds so
I guess we might just as well force-inline them for the other configs.
> Acked-by: Marco Elver <elver@google.com>
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper
2022-02-04 8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
@ 2022-02-04 16:46 ` Luck, Tony
2022-02-04 18:04 ` Borislav Petkov
2022-02-13 10:59 ` [tip: locking/core] " tip-bot2 for Borislav Petkov
1 sibling, 1 reply; 11+ messages in thread
From: Luck, Tony @ 2022-02-04 16:46 UTC (permalink / raw)
To: Borislav Petkov; +Cc: Jakub Kicinski, Linus Torvalds, Marco Elver, X86 ML, LKML
> Also, always inline two more cpumask generic helpers.
>
> allyesconfig:
>
> text data bss dec hex filename
> 190553143 159425889 32076404 382055436 16c5b40c vmlinux.before
> 190551812 159424945 32076404 382053161 16c5ab29 vmlinux.after
That looks odd. You added "always" to some inline functions, which I'd
have thought might cause *more* inlining, and thus an increase in text
size. But it actually went *down* by 1331 bytes.
-Tony
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper
2022-02-04 16:46 ` Luck, Tony
@ 2022-02-04 18:04 ` Borislav Petkov
0 siblings, 0 replies; 11+ messages in thread
From: Borislav Petkov @ 2022-02-04 18:04 UTC (permalink / raw)
To: Luck, Tony; +Cc: Jakub Kicinski, Linus Torvalds, Marco Elver, X86 ML, LKML
On Fri, Feb 04, 2022 at 04:46:24PM +0000, Luck, Tony wrote:
> > Also, always inline two more cpumask generic helpers.
> >
> > allyesconfig:
> >
> > text data bss dec hex filename
> > 190553143 159425889 32076404 382055436 16c5b40c vmlinux.before
> > 190551812 159424945 32076404 382053161 16c5ab29 vmlinux.after
>
> That looks odd. You added "always" to some inline functions, which I'd
> have thought might cause *more* inlining, and thus an increase in text
> size. But it actually went *down* by 1331 bytes.
Or maybe the compiler did some optimizations after the inlining. Here
are the numbers on an allmodconfig - 1073 bytes less with this patch.
text data bss dec hex filename
27409158 31062465 26710144 85181767 513c547 vmlinux.before
27408085 31062821 26710144 85181050 513c27a vmlinux.after
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
^ permalink raw reply [flat|nested] 11+ messages in thread
* [tip: locking/core] x86/ptrace: Always inline v8086_mode() for instrumentation
2022-02-04 8:30 ` [PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation Borislav Petkov
@ 2022-02-13 10:59 ` tip-bot2 for Borislav Petkov
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot2 for Borislav Petkov @ 2022-02-13 10:59 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Borislav Petkov, Marco Elver, x86, linux-kernel
The following commit has been merged into the locking/core branch of tip:
Commit-ID: b008893b08dcc8c30d756db05c229a1491bcb992
Gitweb: https://git.kernel.org/tip/b008893b08dcc8c30d756db05c229a1491bcb992
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Fri, 04 Feb 2022 09:30:14 +01:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Sat, 12 Feb 2022 22:07:13 +01:00
x86/ptrace: Always inline v8086_mode() for instrumentation
Instrumentation glue like KASAN causes the following warning:
vmlinux.o: warning: objtool: mce_gather_info()+0x5f: call to v8086_mode.constprop.0() leaves .noinstr.text section
due to gcc creating a function call for that oneliner. Force-inline it
and even save some vmlinux bytes (.config is close to an allmodconfig):
text data bss dec hex filename
209431677 208257651 34411048 452100376 1af28118 vmlinux.before
209431519 208257615 34411048 452100182 1af28056 vmlinux.after
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20220204083015.17317-3-bp@alien8.de
---
arch/x86/include/asm/ptrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 7036631..4357e0f 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -137,7 +137,7 @@ static __always_inline int user_mode(struct pt_regs *regs)
#endif
}
-static inline int v8086_mode(struct pt_regs *regs)
+static __always_inline int v8086_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_32
return (regs->flags & X86_VM_MASK);
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip: locking/core] cpumask: Add a x86-specific cpumask_clear_cpu() helper
2022-02-04 8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
2022-02-04 16:46 ` Luck, Tony
@ 2022-02-13 10:59 ` tip-bot2 for Borislav Petkov
1 sibling, 0 replies; 11+ messages in thread
From: tip-bot2 for Borislav Petkov @ 2022-02-13 10:59 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Borislav Petkov, Marco Elver, x86, linux-kernel
The following commit has been merged into the locking/core branch of tip:
Commit-ID: f5c54f77b07b278cfde4a654e111c39996ac8b5b
Gitweb: https://git.kernel.org/tip/f5c54f77b07b278cfde4a654e111c39996ac8b5b
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Fri, 04 Feb 2022 09:30:13 +01:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Sat, 12 Feb 2022 18:20:05 +01:00
cpumask: Add a x86-specific cpumask_clear_cpu() helper
Add a x86-specific cpumask_clear_cpu() helper which will be used in
places where the explicit KASAN-instrumentation in the *_bit() helpers
is unwanted.
Also, always inline two more cpumask generic helpers.
allyesconfig:
text data bss dec hex filename
190553143 159425889 32076404 382055436 16c5b40c vmlinux.before
190551812 159424945 32076404 382053161 16c5ab29 vmlinux.after
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20220204083015.17317-2-bp@alien8.de
---
arch/x86/include/asm/cpumask.h | 10 ++++++++++
include/linux/cpumask.h | 4 ++--
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/cpumask.h b/arch/x86/include/asm/cpumask.h
index 3afa990..c5aed9e 100644
--- a/arch/x86/include/asm/cpumask.h
+++ b/arch/x86/include/asm/cpumask.h
@@ -20,11 +20,21 @@ static __always_inline bool arch_cpu_online(int cpu)
{
return arch_test_bit(cpu, cpumask_bits(cpu_online_mask));
}
+
+static __always_inline void arch_cpumask_clear_cpu(int cpu, struct cpumask *dstp)
+{
+ arch_clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
+}
#else
static __always_inline bool arch_cpu_online(int cpu)
{
return cpu == 0;
}
+
+static __always_inline void arch_cpumask_clear_cpu(int cpu, struct cpumask *dstp)
+{
+ return;
+}
#endif
#define arch_cpu_is_offline(cpu) unlikely(!arch_cpu_online(cpu))
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 6b06c69..fe29ac7 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -102,7 +102,7 @@ extern atomic_t __num_online_cpus;
extern cpumask_t cpus_booted_once_mask;
-static inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
+static __always_inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
{
#ifdef CONFIG_DEBUG_PER_CPU_MAPS
WARN_ON_ONCE(cpu >= bits);
@@ -110,7 +110,7 @@ static inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits)
}
/* verify cpu argument to cpumask_* operators */
-static inline unsigned int cpumask_check(unsigned int cpu)
+static __always_inline unsigned int cpumask_check(unsigned int cpu)
{
cpu_max_bits_warn(cpu, nr_cpumask_bits);
return cpu;
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip: ras/core] x86/mce: Use arch atomic and bit helpers
2022-02-04 8:30 ` [PATCH 3/3] x86/mce: Use arch atomic and bit helpers Borislav Petkov
@ 2022-02-14 10:03 ` tip-bot2 for Borislav Petkov
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot2 for Borislav Petkov @ 2022-02-14 10:03 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Borislav Petkov, Marco Elver, x86, linux-kernel
The following commit has been merged into the ras/core branch of tip:
Commit-ID: f11445ba7a1160b87615e3f863a9e66c85189399
Gitweb: https://git.kernel.org/tip/f11445ba7a1160b87615e3f863a9e66c85189399
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Fri, 04 Feb 2022 09:30:15 +01:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Sun, 13 Feb 2022 22:08:27 +01:00
x86/mce: Use arch atomic and bit helpers
The arch helpers do not have explicit KASAN instrumentation. Use them in
noinstr code.
Inline a couple more functions with single call sites, while at it:
mce_severity_amd_smca() has a single call-site which is noinstr so force
the inlining and fix:
vmlinux.o: warning: objtool: mce_severity_amd.constprop.0()+0xca: call to \
mce_severity_amd_smca() leaves .noinstr.text section
Always inline mca_msr_reg():
text data bss dec hex filename
16065240 128031326 36405368 180501934 ac23dae vmlinux.before
16065240 128031294 36405368 180501902 ac23d8e vmlinux.after
and mce_no_way_out() as the latter one is used only once, to fix:
vmlinux.o: warning: objtool: mce_read_aux()+0x53: call to mca_msr_reg() leaves .noinstr.text section
vmlinux.o: warning: objtool: do_machine_check()+0xc9: call to mce_no_way_out() leaves .noinstr.text section
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20220204083015.17317-4-bp@alien8.de
---
arch/x86/kernel/cpu/mce/core.c | 58 +++++++++--------------------
arch/x86/kernel/cpu/mce/internal.h | 23 ++++++++++--
arch/x86/kernel/cpu/mce/severity.c | 2 +-
3 files changed, 41 insertions(+), 42 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 5818b83..0e71474 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -173,27 +173,6 @@ void mce_unregister_decode_chain(struct notifier_block *nb)
}
EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
-u32 mca_msr_reg(int bank, enum mca_msr reg)
-{
- if (mce_flags.smca) {
- switch (reg) {
- case MCA_CTL: return MSR_AMD64_SMCA_MCx_CTL(bank);
- case MCA_ADDR: return MSR_AMD64_SMCA_MCx_ADDR(bank);
- case MCA_MISC: return MSR_AMD64_SMCA_MCx_MISC(bank);
- case MCA_STATUS: return MSR_AMD64_SMCA_MCx_STATUS(bank);
- }
- }
-
- switch (reg) {
- case MCA_CTL: return MSR_IA32_MCx_CTL(bank);
- case MCA_ADDR: return MSR_IA32_MCx_ADDR(bank);
- case MCA_MISC: return MSR_IA32_MCx_MISC(bank);
- case MCA_STATUS: return MSR_IA32_MCx_STATUS(bank);
- }
-
- return 0;
-}
-
static void __print_mce(struct mce *m)
{
pr_emerg(HW_ERR "CPU %d: Machine Check%s: %Lx Bank %d: %016Lx\n",
@@ -814,7 +793,8 @@ EXPORT_SYMBOL_GPL(machine_check_poll);
* the severity assessment code. Pretend that EIPV was set, and take the
* ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
*/
-static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
+static __always_inline void
+quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
{
if (bank != 0)
return;
@@ -838,8 +818,8 @@ static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
* Do a quick check if any of the events requires a panic.
* This decides if we keep the events around or clear them.
*/
-static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
- struct pt_regs *regs)
+static __always_inline int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
+ struct pt_regs *regs)
{
char *tmp = *msg;
int i;
@@ -849,7 +829,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
if (!(m->status & MCI_STATUS_VAL))
continue;
- __set_bit(i, validp);
+ arch___set_bit(i, validp);
if (mce_flags.snb_ifu_quirk)
quirk_sandybridge_ifu(i, m, regs);
@@ -1015,13 +995,13 @@ static noinstr int mce_start(int *no_way_out)
if (!timeout)
return ret;
- atomic_add(*no_way_out, &global_nwo);
+ arch_atomic_add(*no_way_out, &global_nwo);
/*
* Rely on the implied barrier below, such that global_nwo
* is updated before mce_callin.
*/
- order = atomic_inc_return(&mce_callin);
- cpumask_clear_cpu(smp_processor_id(), &mce_missing_cpus);
+ order = arch_atomic_inc_return(&mce_callin);
+ arch_cpumask_clear_cpu(smp_processor_id(), &mce_missing_cpus);
/* Enable instrumentation around calls to external facilities */
instrumentation_begin();
@@ -1029,10 +1009,10 @@ static noinstr int mce_start(int *no_way_out)
/*
* Wait for everyone.
*/
- while (atomic_read(&mce_callin) != num_online_cpus()) {
+ while (arch_atomic_read(&mce_callin) != num_online_cpus()) {
if (mce_timed_out(&timeout,
"Timeout: Not all CPUs entered broadcast exception handler")) {
- atomic_set(&global_nwo, 0);
+ arch_atomic_set(&global_nwo, 0);
goto out;
}
ndelay(SPINUNIT);
@@ -1047,7 +1027,7 @@ static noinstr int mce_start(int *no_way_out)
/*
* Monarch: Starts executing now, the others wait.
*/
- atomic_set(&mce_executing, 1);
+ arch_atomic_set(&mce_executing, 1);
} else {
/*
* Subject: Now start the scanning loop one by one in
@@ -1055,10 +1035,10 @@ static noinstr int mce_start(int *no_way_out)
* This way when there are any shared banks it will be
* only seen by one CPU before cleared, avoiding duplicates.
*/
- while (atomic_read(&mce_executing) < order) {
+ while (arch_atomic_read(&mce_executing) < order) {
if (mce_timed_out(&timeout,
"Timeout: Subject CPUs unable to finish machine check processing")) {
- atomic_set(&global_nwo, 0);
+ arch_atomic_set(&global_nwo, 0);
goto out;
}
ndelay(SPINUNIT);
@@ -1068,7 +1048,7 @@ static noinstr int mce_start(int *no_way_out)
/*
* Cache the global no_way_out state.
*/
- *no_way_out = atomic_read(&global_nwo);
+ *no_way_out = arch_atomic_read(&global_nwo);
ret = order;
@@ -1153,12 +1133,12 @@ out:
return ret;
}
-static void mce_clear_state(unsigned long *toclear)
+static __always_inline void mce_clear_state(unsigned long *toclear)
{
int i;
for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
- if (test_bit(i, toclear))
+ if (arch_test_bit(i, toclear))
mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
}
}
@@ -1208,8 +1188,8 @@ __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final,
int severity, i, taint = 0;
for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
- __clear_bit(i, toclear);
- if (!test_bit(i, valid_banks))
+ arch___clear_bit(i, toclear);
+ if (!arch_test_bit(i, valid_banks))
continue;
if (!mce_banks[i].ctl)
@@ -1244,7 +1224,7 @@ __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final,
severity == MCE_UCNA_SEVERITY) && !no_way_out)
continue;
- __set_bit(i, toclear);
+ arch___set_bit(i, toclear);
/* Machine check event was not enabled. Clear, but ignore. */
if (severity == MCE_NO_SEVERITY)
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 52c6339..a04b61e 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -182,8 +182,6 @@ enum mca_msr {
MCA_MISC,
};
-u32 mca_msr_reg(int bank, enum mca_msr reg);
-
/* Decide whether to add MCE record to MCE event pool or filter it out. */
extern bool filter_mce(struct mce *m);
@@ -209,4 +207,25 @@ static inline void winchip_machine_check(struct pt_regs *regs) {}
noinstr u64 mce_rdmsrl(u32 msr);
+static __always_inline u32 mca_msr_reg(int bank, enum mca_msr reg)
+{
+ if (mce_flags.smca) {
+ switch (reg) {
+ case MCA_CTL: return MSR_AMD64_SMCA_MCx_CTL(bank);
+ case MCA_ADDR: return MSR_AMD64_SMCA_MCx_ADDR(bank);
+ case MCA_MISC: return MSR_AMD64_SMCA_MCx_MISC(bank);
+ case MCA_STATUS: return MSR_AMD64_SMCA_MCx_STATUS(bank);
+ }
+ }
+
+ switch (reg) {
+ case MCA_CTL: return MSR_IA32_MCx_CTL(bank);
+ case MCA_ADDR: return MSR_IA32_MCx_ADDR(bank);
+ case MCA_MISC: return MSR_IA32_MCx_MISC(bank);
+ case MCA_STATUS: return MSR_IA32_MCx_STATUS(bank);
+ }
+
+ return 0;
+}
+
#endif /* __X86_MCE_INTERNAL_H__ */
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index 7aa2bda..ca0d775 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -301,7 +301,7 @@ static noinstr int error_context(struct mce *m, struct pt_regs *regs)
}
}
-static int mce_severity_amd_smca(struct mce *m, enum context err_ctx)
+static __always_inline int mce_severity_amd_smca(struct mce *m, enum context err_ctx)
{
u64 mcx_cfg;
^ permalink raw reply related [flat|nested] 11+ messages in thread
end of thread, other threads:[~2022-02-14 10:39 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-02-04 8:30 [PATCH 0/3] x86/mce: Fix more noinstr fun Borislav Petkov
2022-02-04 8:30 ` [PATCH 1/3] cpumask: Add a x86-specific cpumask_clear_cpu() helper Borislav Petkov
2022-02-04 16:46 ` Luck, Tony
2022-02-04 18:04 ` Borislav Petkov
2022-02-13 10:59 ` [tip: locking/core] " tip-bot2 for Borislav Petkov
2022-02-04 8:30 ` [PATCH 2/3] x86/ptrace: Always inline v8086_mode() for instrumentation Borislav Petkov
2022-02-13 10:59 ` [tip: locking/core] " tip-bot2 for Borislav Petkov
2022-02-04 8:30 ` [PATCH 3/3] x86/mce: Use arch atomic and bit helpers Borislav Petkov
2022-02-14 10:03 ` [tip: ras/core] " tip-bot2 for Borislav Petkov
2022-02-04 11:24 ` [PATCH 0/3] x86/mce: Fix more noinstr fun Marco Elver
2022-02-04 14:48 ` Borislav Petkov
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