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| author | Mateusz Guzik <mjg@FreeBSD.org> | 2021-01-24 04:34:22 +0000 |
|---|---|---|
| committer | Mateusz Guzik <mjg@FreeBSD.org> | 2021-02-01 12:39:15 +0000 |
| commit | 3eae6412b50bbcfe1a7affc26202dc896aedd1ab (patch) | |
| tree | bdfbea58d15afdba7bf578688da7a99164a37de2 | |
| parent | 410994f463351fe2899af77c797dd61c772b02cf (diff) | |
| download | src-3eae6412b50bbcfe1a7affc26202dc896aedd1ab.tar.gz src-3eae6412b50bbcfe1a7affc26202dc896aedd1ab.zip | |
libc: try to skip memcpy in _gettemp
(cherry picked from commit b22fdf45ff8ef1d1f9a6c28f1d7f59ca4b012da6)
| -rw-r--r-- | lib/libc/stdio/mktemp.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/lib/libc/stdio/mktemp.c b/lib/libc/stdio/mktemp.c index c47e0221e5cd..0ede3058a3d5 100644 --- a/lib/libc/stdio/mktemp.c +++ b/lib/libc/stdio/mktemp.c @@ -123,6 +123,7 @@ _gettemp(int dfd, char *path, int *doopen, int domkdir, int slen, int oflags) struct stat sbuf; uint32_t rand; char carrybuf[MAXPATHLEN]; + int saved; if ((doopen != NULL && domkdir) || slen < 0 || (oflags & ~(O_APPEND | O_DIRECT | O_SHLOCK | O_EXLOCK | O_SYNC | @@ -151,9 +152,7 @@ _gettemp(int dfd, char *path, int *doopen, int domkdir, int slen, int oflags) } start = trv + 1; - /* save first combination of random characters */ - memcpy(carrybuf, start, suffp - start); - + saved = 0; oflags |= O_CREAT | O_EXCL | O_RDWR; for (;;) { if (doopen) { @@ -170,6 +169,12 @@ _gettemp(int dfd, char *path, int *doopen, int domkdir, int slen, int oflags) } else if (lstat(path, &sbuf)) return (errno == ENOENT); + /* save first combination of random characters */ + if (!saved) { + memcpy(carrybuf, start, suffp - start); + saved = 1; + } + /* If we have a collision, cycle through the space of filenames */ for (trv = start, carryp = carrybuf;;) { /* have we tried all possible permutations? */ |