When not running as Xen PV guest, patch in the optimal MSR instructions
via alternative and use direct calls otherwise.
This will especially have positive effects for performance when not
running as a Xen PV guest with paravirtualization enabled, as there
will be no call overhead for MSR access functions any longer.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
V3:
- new patch
---
arch/x86/include/asm/paravirt-msr.h | 101 ++++++++++++++++++++++----
arch/x86/include/asm/paravirt_types.h | 1 +
2 files changed, 86 insertions(+), 16 deletions(-)
diff --git a/arch/x86/include/asm/paravirt-msr.h b/arch/x86/include/asm/paravirt-msr.h
index 4ce690b05600..122a7525ae17 100644
--- a/arch/x86/include/asm/paravirt-msr.h
+++ b/arch/x86/include/asm/paravirt-msr.h
@@ -27,33 +27,103 @@ extern struct pv_msr_ops pv_ops_msr;
#define PV_CALLEE_SAVE_REGS_MSR_THUNK(func) \
__PV_CALLEE_SAVE_REGS_THUNK(func, ".text", MSR)
+#define ASM_CLRERR "xor %[err],%[err]\n"
+
+#define PV_RDMSR_VAR(__msr, __val, __type, __func, __err) \
+ asm volatile( \
+ "1:\n" \
+ ALTERNATIVE_2(PARAVIRT_CALL, \
+ RDMSR_AND_SAVE_RESULT ASM_CLRERR, X86_FEATURE_ALWAYS, \
+ ALT_CALL_INSTR, ALT_XEN_CALL) \
+ "2:\n" \
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, __type, %[err]) \
+ : [err] "=d" (__err), [val] "=a" (__val), \
+ ASM_CALL_CONSTRAINT \
+ : paravirt_ptr(pv_ops_msr, __func), "c" (__msr) \
+ : "cc")
+
+#define PV_RDMSR_CONST(__msr, __val, __type, __func, __err) \
+ asm volatile( \
+ "1:\n" \
+ ALTERNATIVE_3(PARAVIRT_CALL, \
+ RDMSR_AND_SAVE_RESULT ASM_CLRERR, X86_FEATURE_ALWAYS, \
+ ASM_RDMSR_IMM ASM_CLRERR, X86_FEATURE_MSR_IMM, \
+ ALT_CALL_INSTR, ALT_XEN_CALL) \
+ "2:\n" \
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, __type, %[err]) \
+ : [err] "=d" (__err), [val] "=a" (__val), \
+ ASM_CALL_CONSTRAINT \
+ : paravirt_ptr(pv_ops_msr, __func), \
+ "c" (__msr), [msr] "i" (__msr) \
+ : "cc")
+
+#define PV_WRMSR_VAR(__msr, __val, __type, __func, __err) \
+({ \
+ unsigned long rdx = rdx; \
+ asm volatile( \
+ "1:\n" \
+ ALTERNATIVE_3(PARAVIRT_CALL, \
+ "wrmsr;" ASM_CLRERR, X86_FEATURE_ALWAYS, \
+ ASM_WRMSRNS ASM_CLRERR, X86_FEATURE_WRMSRNS, \
+ ALT_CALL_INSTR, ALT_XEN_CALL) \
+ "2:\n" \
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, __type, %[err]) \
+ : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
+ : paravirt_ptr(pv_ops_msr, __func), \
+ "0" (__val), "1" ((__val) >> 32), "c" (__msr) \
+ : "memory", "cc"); \
+})
+
+#define PV_WRMSR_CONST(__msr, __val, __type, __func, __err) \
+({ \
+ unsigned long rdx = rdx; \
+ asm volatile( \
+ "1:\n" \
+ ALTERNATIVE_4(PARAVIRT_CALL, \
+ "wrmsr;" ASM_CLRERR, X86_FEATURE_ALWAYS, \
+ ASM_WRMSRNS ASM_CLRERR, X86_FEATURE_WRMSRNS, \
+ ASM_WRMSRNS_IMM ASM_CLRERR, X86_FEATURE_MSR_IMM,\
+ ALT_CALL_INSTR, ALT_XEN_CALL) \
+ "2:\n" \
+ _ASM_EXTABLE_TYPE_REG(1b, 2b, __type, %[err]) \
+ : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
+ : paravirt_ptr(pv_ops_msr, __func), \
+ [val] "0" (__val), "1" ((__val) >> 32), \
+ "c" (__msr), [msr] "i" (__msr) \
+ : "memory", "cc"); \
+})
+
static __always_inline u64 read_msr(u32 msr)
{
u64 val;
+ int err;
- asm volatile(PARAVIRT_CALL
- : "=a" (val), ASM_CALL_CONSTRAINT
- : paravirt_ptr(pv_ops_msr, read_msr), "c" (msr)
- : "rdx");
+ if (__builtin_constant_p(msr))
+ PV_RDMSR_CONST(msr, val, EX_TYPE_RDMSR, read_msr, err);
+ else
+ PV_RDMSR_VAR(msr, val, EX_TYPE_RDMSR, read_msr, err);
return val;
}
static __always_inline void write_msr(u32 msr, u64 val)
{
- asm volatile(PARAVIRT_CALL
- : ASM_CALL_CONSTRAINT
- : paravirt_ptr(pv_ops_msr, write_msr), "c" (msr), "a" (val)
- : "memory", "rdx");
+ int err;
+
+ if (__builtin_constant_p(msr))
+ PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR, write_msr, err);
+ else
+ PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR, write_msr, err);
}
static __always_inline int read_msr_safe(u32 msr, u64 *val)
{
int err;
- asm volatile(PARAVIRT_CALL
- : [err] "=d" (err), "=a" (*val), ASM_CALL_CONSTRAINT
- : paravirt_ptr(pv_ops_msr, read_msr_safe), "c" (msr));
+ if (__builtin_constant_p(msr))
+ PV_RDMSR_CONST(msr, *val, EX_TYPE_RDMSR_SAFE, read_msr_safe, err);
+ else
+ PV_RDMSR_VAR(msr, *val, EX_TYPE_RDMSR_SAFE, read_msr_safe, err);
return err ? -EIO : 0;
}
@@ -62,11 +132,10 @@ static __always_inline int write_msr_safe(u32 msr, u64 val)
{
int err;
- asm volatile(PARAVIRT_CALL
- : [err] "=a" (err), ASM_CALL_CONSTRAINT
- : paravirt_ptr(pv_ops_msr, write_msr_safe),
- "c" (msr), "a" (val)
- : "memory", "rdx");
+ if (__builtin_constant_p(msr))
+ PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR_SAFE, write_msr_safe, err);
+ else
+ PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR_SAFE, write_msr_safe, err);
return err ? -EIO : 0;
}
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 999a5abe54ed..bdaecc54c6ee 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -451,6 +451,7 @@ extern struct paravirt_patch_template pv_ops;
#endif /* __ASSEMBLER__ */
#define ALT_NOT_XEN ALT_NOT(X86_FEATURE_XENPV)
+#define ALT_XEN_CALL ALT_DIRECT_CALL(X86_FEATURE_XENPV)
#ifdef CONFIG_X86_32
/* save and restore all caller-save registers, except return value */
--
2.53.0Hi Juergen,
kernel test robot noticed the following build errors:
[auto build test ERROR on linus/master]
[also build test ERROR on next-20260217]
[cannot apply to tip/x86/core kvm/queue kvm/next kvm/linux-next tip/x86/tdx v6.19]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Juergen-Gross/x86-alternative-Support-alt_replace_call-with-instructions-after-call/20260218-163031
base: linus/master
patch link: https://lore.kernel.org/r/20260218082133.400602-17-jgross%40suse.com
patch subject: [PATCH v3 16/16] x86/paravirt: Use alternatives for MSR access with paravirt
config: x86_64-randconfig-001-20260218 (https://download.01.org/0day-ci/archive/20260218/202602182111.84MpXRx4-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260218/202602182111.84MpXRx4-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602182111.84MpXRx4-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from arch/x86/kernel/asm-offsets.c:9:
In file included from include/linux/crypto.h:18:
In file included from include/linux/slab.h:17:
In file included from include/linux/gfp.h:7:
In file included from include/linux/mmzone.h:22:
In file included from include/linux/mm_types.h:16:
In file included from include/linux/uprobes.h:18:
In file included from include/linux/timer.h:6:
In file included from include/linux/ktime.h:25:
In file included from include/linux/jiffies.h:10:
In file included from include/linux/time.h:60:
In file included from include/linux/time32.h:13:
In file included from include/linux/timex.h:67:
In file included from arch/x86/include/asm/timex.h:6:
In file included from arch/x86/include/asm/tsc.h:11:
In file included from arch/x86/include/asm/msr.h:300:
>> arch/x86/include/asm/paravirt-msr.h:114:23: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
114 | PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR, write_msr, err);
| ^~~ ~~~
arch/x86/include/asm/paravirt-msr.h:91:16: note: expanded from macro 'PV_WRMSR_CONST'
89 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
| ~~~~~
90 | : paravirt_ptr(pv_ops_msr, __func), \
91 | [val] "0" (__val), "1" ((__val) >> 32), \
| ^~~~~
arch/x86/include/asm/paravirt-msr.h:116:21: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
116 | PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR, write_msr, err);
| ^~~ ~~~
arch/x86/include/asm/paravirt-msr.h:73:10: note: expanded from macro 'PV_WRMSR_VAR'
71 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
| ~~~~~
72 | : paravirt_ptr(pv_ops_msr, __func), \
73 | "0" (__val), "1" ((__val) >> 32), "c" (__msr) \
| ^~~~~
arch/x86/include/asm/paravirt-msr.h:136:23: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
136 | PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR_SAFE, write_msr_safe, err);
| ^~~ ~~~
arch/x86/include/asm/paravirt-msr.h:91:16: note: expanded from macro 'PV_WRMSR_CONST'
89 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
| ~~~~~
90 | : paravirt_ptr(pv_ops_msr, __func), \
91 | [val] "0" (__val), "1" ((__val) >> 32), \
| ^~~~~
arch/x86/include/asm/paravirt-msr.h:138:21: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
138 | PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR_SAFE, write_msr_safe, err);
| ^~~ ~~~
arch/x86/include/asm/paravirt-msr.h:73:10: note: expanded from macro 'PV_WRMSR_VAR'
71 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
| ~~~~~
72 | : paravirt_ptr(pv_ops_msr, __func), \
73 | "0" (__val), "1" ((__val) >> 32), "c" (__msr) \
| ^~~~~
In file included from arch/x86/kernel/asm-offsets.c:10:
In file included from include/crypto/aria.h:22:
In file included from include/linux/module.h:20:
In file included from include/linux/elf.h:6:
In file included from arch/x86/include/asm/elf.h:10:
In file included from arch/x86/include/asm/ia32.h:7:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:5:
In file included from include/linux/fs/super.h:5:
In file included from include/linux/fs/super_types.h:13:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:98:11: warning: array index 3 is past the end of the array (that has type 'unsigned long[1]') [-Warray-bounds]
98 | return (set->sig[3] | set->sig[2] |
| ^ ~
arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
24 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/x86/kernel/asm-offsets.c:10:
In file included from include/crypto/aria.h:22:
In file included from include/linux/module.h:20:
In file included from include/linux/elf.h:6:
In file included from arch/x86/include/asm/elf.h:10:
In file included from arch/x86/include/asm/ia32.h:7:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:5:
In file included from include/linux/fs/super.h:5:
In file included from include/linux/fs/super_types.h:13:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:98:25: warning: array index 2 is past the end of the array (that has type 'unsigned long[1]') [-Warray-bounds]
98 | return (set->sig[3] | set->sig[2] |
| ^ ~
arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
24 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/x86/kernel/asm-offsets.c:10:
In file included from include/crypto/aria.h:22:
In file included from include/linux/module.h:20:
In file included from include/linux/elf.h:6:
In file included from arch/x86/include/asm/elf.h:10:
In file included from arch/x86/include/asm/ia32.h:7:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:5:
In file included from include/linux/fs/super.h:5:
In file included from include/linux/fs/super_types.h:13:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:99:4: warning: array index 1 is past the end of the array (that has type 'unsigned long[1]') [-Warray-bounds]
99 | set->sig[1] | set->sig[0]) == 0;
| ^ ~
arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
24 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/x86/kernel/asm-offsets.c:10:
In file included from include/crypto/aria.h:22:
In file included from include/linux/module.h:20:
In file included from include/linux/elf.h:6:
In file included from arch/x86/include/asm/elf.h:10:
In file included from arch/x86/include/asm/ia32.h:7:
In file included from include/linux/compat.h:17:
In file included from include/linux/fs.h:5:
vim +114 arch/x86/include/asm/paravirt-msr.h
108
109 static __always_inline void write_msr(u32 msr, u64 val)
110 {
111 int err;
112
113 if (__builtin_constant_p(msr))
> 114 PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR, write_msr, err);
115 else
116 PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR, write_msr, err);
117 }
118
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On 18.02.26 14:49, kernel test robot wrote:
> Hi Juergen,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on next-20260217]
> [cannot apply to tip/x86/core kvm/queue kvm/next kvm/linux-next tip/x86/tdx v6.19]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Juergen-Gross/x86-alternative-Support-alt_replace_call-with-instructions-after-call/20260218-163031
> base: linus/master
> patch link: https://lore.kernel.org/r/20260218082133.400602-17-jgross%40suse.com
> patch subject: [PATCH v3 16/16] x86/paravirt: Use alternatives for MSR access with paravirt
> config: x86_64-randconfig-001-20260218 (https://download.01.org/0day-ci/archive/20260218/202602182111.84MpXRx4-lkp@intel.com/config)
> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260218/202602182111.84MpXRx4-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602182111.84MpXRx4-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> In file included from arch/x86/kernel/asm-offsets.c:9:
> In file included from include/linux/crypto.h:18:
> In file included from include/linux/slab.h:17:
> In file included from include/linux/gfp.h:7:
> In file included from include/linux/mmzone.h:22:
> In file included from include/linux/mm_types.h:16:
> In file included from include/linux/uprobes.h:18:
> In file included from include/linux/timer.h:6:
> In file included from include/linux/ktime.h:25:
> In file included from include/linux/jiffies.h:10:
> In file included from include/linux/time.h:60:
> In file included from include/linux/time32.h:13:
> In file included from include/linux/timex.h:67:
> In file included from arch/x86/include/asm/timex.h:6:
> In file included from arch/x86/include/asm/tsc.h:11:
> In file included from arch/x86/include/asm/msr.h:300:
>>> arch/x86/include/asm/paravirt-msr.h:114:23: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
> 114 | PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR, write_msr, err);
> | ^~~ ~~~
> arch/x86/include/asm/paravirt-msr.h:91:16: note: expanded from macro 'PV_WRMSR_CONST'
> 89 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
> | ~~~~~
> 90 | : paravirt_ptr(pv_ops_msr, __func), \
> 91 | [val] "0" (__val), "1" ((__val) >> 32), \
> | ^~~~~
> arch/x86/include/asm/paravirt-msr.h:116:21: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
> 116 | PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR, write_msr, err);
> | ^~~ ~~~
> arch/x86/include/asm/paravirt-msr.h:73:10: note: expanded from macro 'PV_WRMSR_VAR'
> 71 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
> | ~~~~~
> 72 | : paravirt_ptr(pv_ops_msr, __func), \
> 73 | "0" (__val), "1" ((__val) >> 32), "c" (__msr) \
> | ^~~~~
> arch/x86/include/asm/paravirt-msr.h:136:23: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
> 136 | PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR_SAFE, write_msr_safe, err);
> | ^~~ ~~~
> arch/x86/include/asm/paravirt-msr.h:91:16: note: expanded from macro 'PV_WRMSR_CONST'
> 89 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
> | ~~~~~
> 90 | : paravirt_ptr(pv_ops_msr, __func), \
> 91 | [val] "0" (__val), "1" ((__val) >> 32), \
> | ^~~~~
> arch/x86/include/asm/paravirt-msr.h:138:21: error: unsupported inline asm: input with type 'u64' (aka 'unsigned long long') matching output with type 'int'
> 138 | PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR_SAFE, write_msr_safe, err);
> | ^~~ ~~~
> arch/x86/include/asm/paravirt-msr.h:73:10: note: expanded from macro 'PV_WRMSR_VAR'
> 71 | : [err] "=a" (__err), "=d" (rdx), ASM_CALL_CONSTRAINT \
> | ~~~~~
> 72 | : paravirt_ptr(pv_ops_msr, __func), \
> 73 | "0" (__val), "1" ((__val) >> 32), "c" (__msr) \
> | ^~~~~
> In file included from arch/x86/kernel/asm-offsets.c:10:
> In file included from include/crypto/aria.h:22:
> In file included from include/linux/module.h:20:
> In file included from include/linux/elf.h:6:
> In file included from arch/x86/include/asm/elf.h:10:
> In file included from arch/x86/include/asm/ia32.h:7:
> In file included from include/linux/compat.h:17:
> In file included from include/linux/fs.h:5:
> In file included from include/linux/fs/super.h:5:
> In file included from include/linux/fs/super_types.h:13:
> In file included from include/linux/percpu-rwsem.h:7:
> In file included from include/linux/rcuwait.h:6:
> In file included from include/linux/sched/signal.h:6:
> include/linux/signal.h:98:11: warning: array index 3 is past the end of the array (that has type 'unsigned long[1]') [-Warray-bounds]
> 98 | return (set->sig[3] | set->sig[2] |
> | ^ ~
> arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
> 24 | unsigned long sig[_NSIG_WORDS];
> | ^
> In file included from arch/x86/kernel/asm-offsets.c:10:
> In file included from include/crypto/aria.h:22:
> In file included from include/linux/module.h:20:
> In file included from include/linux/elf.h:6:
> In file included from arch/x86/include/asm/elf.h:10:
> In file included from arch/x86/include/asm/ia32.h:7:
> In file included from include/linux/compat.h:17:
> In file included from include/linux/fs.h:5:
> In file included from include/linux/fs/super.h:5:
> In file included from include/linux/fs/super_types.h:13:
> In file included from include/linux/percpu-rwsem.h:7:
> In file included from include/linux/rcuwait.h:6:
> In file included from include/linux/sched/signal.h:6:
> include/linux/signal.h:98:25: warning: array index 2 is past the end of the array (that has type 'unsigned long[1]') [-Warray-bounds]
> 98 | return (set->sig[3] | set->sig[2] |
> | ^ ~
> arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
> 24 | unsigned long sig[_NSIG_WORDS];
> | ^
> In file included from arch/x86/kernel/asm-offsets.c:10:
> In file included from include/crypto/aria.h:22:
> In file included from include/linux/module.h:20:
> In file included from include/linux/elf.h:6:
> In file included from arch/x86/include/asm/elf.h:10:
> In file included from arch/x86/include/asm/ia32.h:7:
> In file included from include/linux/compat.h:17:
> In file included from include/linux/fs.h:5:
> In file included from include/linux/fs/super.h:5:
> In file included from include/linux/fs/super_types.h:13:
> In file included from include/linux/percpu-rwsem.h:7:
> In file included from include/linux/rcuwait.h:6:
> In file included from include/linux/sched/signal.h:6:
> include/linux/signal.h:99:4: warning: array index 1 is past the end of the array (that has type 'unsigned long[1]') [-Warray-bounds]
> 99 | set->sig[1] | set->sig[0]) == 0;
> | ^ ~
> arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
> 24 | unsigned long sig[_NSIG_WORDS];
> | ^
> In file included from arch/x86/kernel/asm-offsets.c:10:
> In file included from include/crypto/aria.h:22:
> In file included from include/linux/module.h:20:
> In file included from include/linux/elf.h:6:
> In file included from arch/x86/include/asm/elf.h:10:
> In file included from arch/x86/include/asm/ia32.h:7:
> In file included from include/linux/compat.h:17:
> In file included from include/linux/fs.h:5:
>
>
> vim +114 arch/x86/include/asm/paravirt-msr.h
>
> 108
> 109 static __always_inline void write_msr(u32 msr, u64 val)
> 110 {
> 111 int err;
> 112
> 113 if (__builtin_constant_p(msr))
> > 114 PV_WRMSR_CONST(msr, val, EX_TYPE_WRMSR, write_msr, err);
> 115 else
> 116 PV_WRMSR_VAR(msr, val, EX_TYPE_WRMSR, write_msr, err);
> 117 }
> 118
>
Will be fixed in V4.
Juergen
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