pstore/ram: Avoid needless alloc during header write

Since the header is a fixed small maximum size, just use a stack variable
to avoid memory allocation in the write path.

Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2019-02-12 13:09:36 -08:00
parent 47afd7ae65
commit 93ee4b7d9f
1 changed files with 3 additions and 7 deletions

View File

@ -345,19 +345,15 @@ out:
static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
struct pstore_record *record)
{
char *hdr;
char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
size_t len;
hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
len = scnprintf(hdr, sizeof(hdr),
RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
(time64_t)record->time.tv_sec,
record->time.tv_nsec / 1000,
record->compressed ? 'C' : 'D');
if (WARN_ON_ONCE(!hdr))
return 0;
len = strlen(hdr);
persistent_ram_write(prz, hdr, len);
kfree(hdr);
return len;
}