Commit 5fe9d8ca authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

coredump: cn_vprintf() has no reason to call vsnprintf() twice

cn_vprintf() looks really overcomplicated and sub-optimal.  We do not need
vsnprintf(NULL) to calculate the size we need, we can simply try to print
into the current buffer and expand/retry only if necessary.
Signed-off-by: default avatarOleg Nesterov <>
Cc: Andi Kleen <>
Cc: Colin Walters <>
Cc: Denys Vlasenko <>
Cc: Jiri Slaby <>
Cc: Lennart Poettering <>
Cc: Lucas De Marchi <>
Acked-by: default avatarNeil Horman <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent bc03c691
......@@ -71,26 +71,20 @@ static int expand_corename(struct core_name *cn)
static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg)
char *cur;
int need;
int ret;
need = vsnprintf(NULL, 0, fmt, arg);
if (likely(need < cn->size - cn->used - 1))
goto out_printf;
ret = expand_corename(cn);
if (ret)
goto expand_fail;
int free, need;
free = cn->size - cn->used;
need = vsnprintf(cn->corename + cn->used, free, fmt, arg);
if (need < free) {
cn->used += need;
return 0;
cur = cn->corename + cn->used;
vsnprintf(cur, need + 1, fmt, arg);
cn->used += need;
return 0;
if (!expand_corename(cn))
goto again;
return ret;
return -ENOMEM;
static int cn_printf(struct core_name *cn, const char *fmt, ...)
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