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authorLinus Torvalds <torvalds@linux-foundation.org>2022-11-01 13:15:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-11-01 13:15:14 -0700
commit54917c90c2cfc6cf3be6deb143cf3967b6dd8d3b (patch)
tree194bc6b99ef2525f017d4f6097bfb2188ace9002 /tools/include
parentf526d6a82242f7ee72d2a4448eb492622cb7d556 (diff)
parentb3f4f51ea68a495f8a5956064c33dce711a2df91 (diff)
downloadlinux-54917c90c2cfc6cf3be6deb143cf3967b6dd8d3b.tar.bz2
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/include')
-rw-r--r--tools/include/nolibc/string.h17
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))