| Message ID | 20250321144822.324050-5-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | vsprintf: Add __printf attribute to where it's required | expand |
On Fri, 21 Mar 2025 16:40:50 +0200 Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > Binary printf() functions are using printf() type of format, and compiler > is not happy about them as is: > > lib/vsprintf.c:3130:47: error: function ‘vbin_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] > lib/vsprintf.c:3298:33: error: function ‘bstr_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] BTW, I find it disturbing that the compiler is set to "error" on a warning that "might be a candidate". What happens if it is not? We have to play games to quiet it. Adding __printf() attributes to stubs seems to be a case of the compiler causing more problems than its worth :-/ I honestly hate this error on warning because it causes real pain when debugging. There's a lot of times I don't know if the value is long or long long, and when I get it wrong, my printk() causes the build to fail. It's especially annoying when both long and long long are the same size! Fixing theses stupid errors takes a non trivial amount of time away from actual debugging. -- Steve > > Fix the compilation errors by adding __printf() attribute. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
On Mon, Mar 24, 2025 at 03:20:12PM -0400, Steven Rostedt wrote: > On Fri, 21 Mar 2025 16:40:50 +0200 > Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > > Binary printf() functions are using printf() type of format, and compiler > > is not happy about them as is: > > > > lib/vsprintf.c:3130:47: error: function ‘vbin_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] > > lib/vsprintf.c:3298:33: error: function ‘bstr_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] > > BTW, I find it disturbing that the compiler is set to "error" on a warning > that "might be a candidate". What happens if it is not? We have to play > games to quiet it. > > Adding __printf() attributes to stubs seems to be a case of the compiler > causing more problems than its worth :-/ > > I honestly hate this error on warning because it causes real pain when > debugging. Tell it to Linus :-) since it was him who enabled that default. And since it's there and defconfigs are also part of the kernel I can't easy remove that, and TBH I even won't dare doing that. > There's a lot of times I don't know if the value is long or long > long, and when I get it wrong, my printk() causes the build to fail. It's > especially annoying when both long and long long are the same size! > > Fixing theses stupid errors takes a non trivial amount of time away from > actual debugging. You (actually me) fix them once, currently CI's typically run with W=1, but with WERROR=n. Which means that the new code that is not fixed a priori, will induce the CI red report. > > Fix the compilation errors by adding __printf() attribute. > > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/include/linux/string.h b/include/linux/string.h index f8e21e80942f..f15696e8e4d4 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -336,8 +336,8 @@ int __sysfs_match_string(const char * const *array, size_t n, const char *s); #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) #ifdef CONFIG_BINARY_PRINTF -int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); -int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); +__printf(3, 0) int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); +__printf(3, 0) int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); #endif extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
Binary printf() functions are using printf() type of format, and compiler is not happy about them as is: lib/vsprintf.c:3130:47: error: function ‘vbin_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] lib/vsprintf.c:3298:33: error: function ‘bstr_printf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] Fix the compilation errors by adding __printf() attribute. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- include/linux/string.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)