perf/x86: Fix 'may be used uninitialized' build warnings in core.c
Subsystems (2)
PATCH 1/1 perf/x86: Fix 'may be used uninitialized' build warnings in core.c
This patch fixes the following build warnings in core.c:
linux/arch/x86/events/core.c: In function ‘init_hw_perf_events’:linux/include/linux/printk.h:292:2: warning: ‘reg_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^linux/arch/x86/events/core.c:194:14: note: ‘reg_fail’ was declared here int i, reg, reg_fail, ret = 0;
linux/include/linux/printk.h:292:2: warning: ‘val_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^linux/arch/x86/events/core.c:193:11: note: ‘val_fail’ was declared here u64 val, val_fail, val_new= ~0;
--- arch/x86/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
arch/x86/events/core.c +2 -2
@@ -190,8 +190,8 @@ static void release_pmc_hardware(void) {}static bool check_hw_exists (void ) { -u64 val, val_fail, val_new= ~0 ; -int i, reg, reg_fail, ret =0 ; +u64 val, val_fail =0 , val_new= ~0 ; +int i, reg, reg_fail =0 , ret =0 ;int bios_fail =0 ;int reg_safe =-1 ;
Signature · 1 line
2.7.4
Quoted 27 lines · Augusto Mecking Caringi
This patch fixes the following build warnings in
core.c:
linux/arch/x86/events/core.c: In function ‘init_hw_perf_events’:linux/include/linux/printk.h:292:2: warning: ‘reg_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized]printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^linux/arch/x86/events/core.c:194:14: note: ‘reg_fail’ was declared here int i, reg,reg_fail, ret = 0;
linux/include/linux/printk.h:292:2: warning: ‘val_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized]printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^linux/arch/x86/events/core.c:193:11: note: ‘val_fail’ was declared here u64 val,val_fail, val_new= ~0;Signed-off-by Augusto Mecking Caringi <[email protected]>--- arch/x86/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)arch/x86/events/core.c +0
-0
arch/x86/events/core.c static void release_pmc_hardware(void) {} · line 196
Quoted 9 lines
arch/x86/events/core.c +2
-2@@ -190,8 +190,8 @@ static void release_pmc_hardware(void) {}static bool check_hw_exists (void ) { -u64 val, val_fail, val_new= ~0 ; -int i, reg, reg_fail, ret =0 ; +u64 val, val_fail =0 , val_new= ~0 ; +int i, reg, reg_fail =0 , ret =0 ;int bios_fail =0 ;int reg_safe =-1 ;
What's not mentioned in the changelog is whether the warning was right or wrong - i.e. whether this patch changes behavior or silences a false positive warning.
Whether the compiler changed object code as result of this change would be good to know as well.
Thanks,
Ingo