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| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2017-07-10 15:51:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-10 16:32:34 -0700 |
| commit | b7b2562f7252878e18de60c24f320052076f9de8 (patch) | |
| tree | f5b30652d73cbfe14e010044489bc06b37d62bcf /kernel/groups.c | |
| parent | 9dcdcea11491f6eee65bd1b352293ca01e4b7997 (diff) | |
| download | lwn-b7b2562f7252878e18de60c24f320052076f9de8.tar.gz lwn-b7b2562f7252878e18de60c24f320052076f9de8.zip | |
kernel/groups.c: use sort library function
setgroups is not exactly a hot path, so we might as well use the library
function instead of open-coding the sorting. Saves ~150 bytes.
Link: http://lkml.kernel.org/r/1497301378-22739-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/groups.c')
| -rw-r--r-- | kernel/groups.c | 35 |
1 files changed, 11 insertions, 24 deletions
diff --git a/kernel/groups.c b/kernel/groups.c index d09727692a2a..434f6665f187 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -5,6 +5,7 @@ #include <linux/export.h> #include <linux/slab.h> #include <linux/security.h> +#include <linux/sort.h> #include <linux/syscalls.h> #include <linux/user_namespace.h> #include <linux/vmalloc.h> @@ -76,32 +77,18 @@ static int groups_from_user(struct group_info *group_info, return 0; } -/* a simple Shell sort */ +static int gid_cmp(const void *_a, const void *_b) +{ + kgid_t a = *(kgid_t *)_a; + kgid_t b = *(kgid_t *)_b; + + return gid_gt(a, b) - gid_lt(a, b); +} + static void groups_sort(struct group_info *group_info) { - int base, max, stride; - int gidsetsize = group_info->ngroups; - - for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) - ; /* nothing */ - stride /= 3; - - while (stride) { - max = gidsetsize - stride; - for (base = 0; base < max; base++) { - int left = base; - int right = left + stride; - kgid_t tmp = group_info->gid[right]; - - while (left >= 0 && gid_gt(group_info->gid[left], tmp)) { - group_info->gid[right] = group_info->gid[left]; - right = left; - left -= stride; - } - group_info->gid[right] = tmp; - } - stride /= 3; - } + sort(group_info->gid, group_info->ngroups, sizeof(*group_info->gid), + gid_cmp, NULL); } /* a simple bsearch */ |