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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-11-01 13:15:14 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-11-01 13:15:14 -0700 |
commit | 54917c90c2cfc6cf3be6deb143cf3967b6dd8d3b (patch) | |
tree | 194bc6b99ef2525f017d4f6097bfb2188ace9002 /tools | |
parent | f526d6a82242f7ee72d2a4448eb492622cb7d556 (diff) | |
parent | b3f4f51ea68a495f8a5956064c33dce711a2df91 (diff) | |
download | linux-stable-54917c90c2cfc6cf3be6deb143cf3967b6dd8d3b.tar.gz linux-stable-54917c90c2cfc6cf3be6deb143cf3967b6dd8d3b.tar.bz2 linux-stable-54917c90c2cfc6cf3be6deb143cf3967b6dd8d3b.zip |
Merge tag 'nolibc-urgent.2022.10.28a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull nolibc fixes from Paul McKenney:
"This contains a couple of fixes for string-function bugs"
* tag 'nolibc-urgent.2022.10.28a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
tools/nolibc/string: Fix memcmp() implementation
tools/nolibc: Fix missing strlen() definition and infinite loop with gcc-12
Diffstat (limited to 'tools')
-rw-r--r-- | tools/include/nolibc/string.h | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h index bef35bee9c44..ad97c0d522b8 100644 --- a/tools/include/nolibc/string.h +++ b/tools/include/nolibc/string.h @@ -19,9 +19,9 @@ static __attribute__((unused)) int memcmp(const void *s1, const void *s2, size_t n) { size_t ofs = 0; - char c1 = 0; + int c1 = 0; - while (ofs < n && !(c1 = ((char *)s1)[ofs] - ((char *)s2)[ofs])) { + while (ofs < n && !(c1 = ((unsigned char *)s1)[ofs] - ((unsigned char *)s2)[ofs])) { ofs++; } return c1; @@ -125,14 +125,18 @@ char *strcpy(char *dst, const char *src) } /* this function is only used with arguments that are not constants or when - * it's not known because optimizations are disabled. + * it's not known because optimizations are disabled. Note that gcc 12 + * recognizes an strlen() pattern and replaces it with a jump to strlen(), + * thus itself, hence the asm() statement below that's meant to disable this + * confusing practice. */ static __attribute__((unused)) -size_t nolibc_strlen(const char *str) +size_t strlen(const char *str) { size_t len; - for (len = 0; str[len]; len++); + for (len = 0; str[len]; len++) + asm(""); return len; } @@ -140,13 +144,12 @@ size_t nolibc_strlen(const char *str) * the two branches, then will rely on an external definition of strlen(). */ #if defined(__OPTIMIZE__) +#define nolibc_strlen(x) strlen(x) #define strlen(str) ({ \ __builtin_constant_p((str)) ? \ __builtin_strlen((str)) : \ nolibc_strlen((str)); \ }) -#else -#define strlen(str) nolibc_strlen((str)) #endif static __attribute__((unused)) |