diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2015-04-15 16:17:05 -0700 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:59:16 +0200 |
| commit | 87bd8bce9cf383f5e82ab86f3297b854bbcd8e0a (patch) | |
| tree | 25e09cfc39448a5af0f08f5d9d8cbb43d7a6772d | |
| parent | 26bcb4f61c9e4b7057d20476164b1baac7d84699 (diff) | |
lib/vsprintf.c: reduce stack use in number()
At least since the initial git commit, when base was passed as a separate
parameter, number() has only been called with bases 8, 10 and 16. I'm
guessing that 66 was to accommodate 64 0/1, a sign and a '\0', but the
buffer is only used for the actual digits. Octal digits carry 3 bits of
information, so 24 is enough. Spell that 3*sizeof(num) so one less place
needs to be changed should long long ever be 128 bits. Also remove the
commented-out code that would handle an arbitrary base.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | lib/vsprintf.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 904e83304..0cf408ae6 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -385,7 +385,7 @@ char *number(char *buf, char *end, unsigned long long num, /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ - char tmp[66]; + char tmp[3 * sizeof(num)]; char sign; char locase; int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); @@ -422,11 +422,6 @@ char *number(char *buf, char *end, unsigned long long num, i = 0; if (num < spec.base) tmp[i++] = digits[num] | locase; - /* Generic code, for any base: - else do { - tmp[i++] = (digits[do_div(num,base)] | locase); - } while (num != 0); - */ else if (spec.base != 10) { /* 8 or 16 */ int mask = spec.base - 1; int shift = 3; |