Messages in this thread Patch in this message | | | From | Ammar Faizi <> | Subject | [RFC PATCH v2 8/8] tools/include/string: Implement `strdup()` and `strndup()` | Date | Tue, 22 Mar 2022 17:21:15 +0700 |
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These functions are currently only available on architectures that have my_syscall6() macro implemented. Since these functions use malloc(), malloc() uses mmap(), mmap() depends on my_syscall6() macro.
On architectures that don't support my_syscall6(), these function will always return NULL with errno set to ENOSYS.
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> ---
@@ Changelog:
Link RFC v1: https://lore.kernel.org/lkml/20220320093750.159991-7-ammarfaizi2@gnuweeb.org/ RFC v1 -> RFC v2: - Update strdup and strndup implementation, use strlen and strnlen to get the string length first (comment from Willy and Alviro). - Fix the subject line prefix, it was "tools/include/string: ", it should be "tools/nolibc/string: ". - Update the commit message. --- tools/include/nolibc/string.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h index 1426eefc1ef2..bcc76f89199e 100644 --- a/tools/include/nolibc/string.h +++ b/tools/include/nolibc/string.h @@ -9,6 +9,8 @@ #include "std.h" +static void *malloc(size_t len); + /* * As much as possible, please keep functions alphabetically sorted. */ @@ -147,6 +149,36 @@ size_t strnlen(const char *str, size_t maxlen) return len; } +static __attribute__((unused)) +char *strdup(const char *str) +{ + size_t len; + char *ret; + + len = strlen(str); + ret = malloc(len + 1); + if (__builtin_expect(ret != NULL, 1)) + memcpy(ret, str, len + 1); + + return ret; +} + +static __attribute__((unused)) +char *strndup(const char *str, size_t maxlen) +{ + size_t len; + char *ret; + + len = strnlen(str, maxlen); + ret = malloc(len + 1); + if (__builtin_expect(ret != NULL, 1)) { + memcpy(ret, str, len); + ret[len] = '\0'; + } + + return ret; +} + static __attribute__((unused)) size_t strlcat(char *dst, const char *src, size_t size) { -- Ammar Faizi
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