diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2015-04-16 01:17:05 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-16 01:35:23 +0200 |
| commit | e26c12c777118d65aeb97eb1651338e7decae80e (patch) | |
| tree | 55300d96e94c3e9efdaf434b8473ccc02536ba7d /lib/vsprintf.c | |
| parent | lib/vsprintf.c: eliminate some branches (diff) | |
| download | linux-e26c12c777118d65aeb97eb1651338e7decae80e.tar.xz linux-e26c12c777118d65aeb97eb1651338e7decae80e.zip | |
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>
Diffstat (limited to 'lib/vsprintf.c')
| -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 318d583fe862..98f1ce907d3d 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -386,7 +386,7 @@ 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); @@ -423,11 +423,6 @@ 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; |