On Tue, Mar 7, 2017 at 10:16 AM, Ingo Molnar <[email protected]> wrote: > > * Nicolas Iooss <[email protected]> wrote: > >> Adding such an attribute helps to detect errors in the format string at >> build time. After doing this, the compiler complains about some issues: >> >> arch/x86/tools/relocs.c:460:5: error: format specifies type 'int' >> but the argument has type 'Elf64_Xword' (aka 'unsigned long') >> [-Werror,-Wformat] >> sec->shdr.sh_size); >> ^~~~~~~~~~~~~~~~~ >> arch/x86/tools/relocs.c:464:5: error: format specifies type 'int' >> but the argument has type 'Elf64_Off' (aka 'unsigned long') >> [-Werror,-Wformat] >> sec->shdr.sh_offset, strerror(errno)); >> ^~~~~~~~~~~~~~~~~~~ >> >> When relocs.c is included by relocs_32.c, sec->shdr.sh_size and >> sec->shdr.sh_offset are 32-bit unsigned integers. When the file is >> included by relocs_64.c, these expressions are 64-bit unsigned integers. >> >> Add casts to unsigned long long, which length is always 64-bit, and use >> %llu to format sec->shdr.sh_size and sec->shdr.sh_offset in relocs.c. >> >> While at it, constify the format attribute of die(). >> >> Signed-off-by: Nicolas Iooss <[email protected]> >> --- >> arch/x86/tools/relocs.c | 31 +++++++++++++++++-------------- >> arch/x86/tools/relocs.h | 3 ++- >> arch/x86/tools/relocs_common.c | 2 +- >> 3 files changed, 20 insertions(+), 16 deletions(-) >> >> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c >> index 73eb7fd4aec4..3cc02065c677 100644 >> --- a/arch/x86/tools/relocs.c >> +++ b/arch/x86/tools/relocs.c >> @@ -397,8 +397,8 @@ static void read_shdrs(FILE *fp) >> ehdr.e_shnum); >> } >> if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) { >> - die("Seek to %d failed: %s\n", >> - ehdr.e_shoff, strerror(errno)); >> + die("Seek to %llu failed: %s\n", >> + (unsigned long long)ehdr.e_shoff, strerror(errno)); > > Isn't "(u64)" shorter to write?
u64 does not seem to be defined in this file right now. Adding "#include <linux/types.h>" defines u64 and __u64 in the following way: - "typedef uint64_t u64;" from tools/include/linux/types.h - "typedef unsigned long long __u64;" from /usr/include/asm-generic/int-ll64.h uint64_t is unsigned long on x86-64 and gcc complains when using %llu on such a type, so using a cast to u64 forces using PRIu64 too. Nevertheless "(__u64)" is shorter than "(unsigned long long)" and seems to work fine in my quick tests because it is always unsigned long long (on both x86-32 and x86-64). Would you prefer to use this cast? Thanks, Nicolas
