f787d9519f
This was found during chasing down the header output regression. The strbuf_addf() was checking buffer length with a result of vscnprintf() which cannot be greater than that of strbuf_avail(). Since numa topology and pmu mapping info in header were converted to use strbuf, it sometimes caused uninteresting behaviors with the broken strbuf. Fix it by using vsnprintf() which returns desired output string length regardless of the available buffer size and grow the buffer if needed. Reported-by: Andrew Jones <drjones@redhat.com> Tested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andrew Jones <drjones@redhat.com> Link: http://lkml.kernel.org/r/1350999890-6920-2-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
135 lines
2.9 KiB
C
135 lines
2.9 KiB
C
#include "cache.h"
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#include <linux/kernel.h>
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int prefixcmp(const char *str, const char *prefix)
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{
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for (; ; str++, prefix++)
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if (!*prefix)
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return 0;
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else if (*str != *prefix)
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return (unsigned char)*prefix - (unsigned char)*str;
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}
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/*
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* Used as the default ->buf value, so that people can always assume
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* buf is non NULL and ->buf is NUL terminated even for a freshly
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* initialized strbuf.
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*/
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char strbuf_slopbuf[1];
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void strbuf_init(struct strbuf *sb, ssize_t hint)
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{
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sb->alloc = sb->len = 0;
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sb->buf = strbuf_slopbuf;
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if (hint)
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strbuf_grow(sb, hint);
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}
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void strbuf_release(struct strbuf *sb)
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{
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if (sb->alloc) {
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free(sb->buf);
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strbuf_init(sb, 0);
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}
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}
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char *strbuf_detach(struct strbuf *sb, size_t *sz)
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{
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char *res = sb->alloc ? sb->buf : NULL;
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if (sz)
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*sz = sb->len;
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strbuf_init(sb, 0);
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return res;
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}
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void strbuf_grow(struct strbuf *sb, size_t extra)
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{
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if (sb->len + extra + 1 <= sb->len)
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die("you want to use way too much memory");
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if (!sb->alloc)
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sb->buf = NULL;
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ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
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}
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static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
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const void *data, size_t dlen)
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{
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if (pos + len < pos)
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die("you want to use way too much memory");
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if (pos > sb->len)
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die("`pos' is too far after the end of the buffer");
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if (pos + len > sb->len)
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die("`pos + len' is too far after the end of the buffer");
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if (dlen >= len)
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strbuf_grow(sb, dlen - len);
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memmove(sb->buf + pos + dlen,
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sb->buf + pos + len,
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sb->len - pos - len);
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memcpy(sb->buf + pos, data, dlen);
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strbuf_setlen(sb, sb->len + dlen - len);
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}
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void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
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{
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strbuf_splice(sb, pos, len, NULL, 0);
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}
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void strbuf_add(struct strbuf *sb, const void *data, size_t len)
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{
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strbuf_grow(sb, len);
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memcpy(sb->buf + sb->len, data, len);
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strbuf_setlen(sb, sb->len + len);
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}
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void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
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{
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int len;
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va_list ap;
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if (!strbuf_avail(sb))
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strbuf_grow(sb, 64);
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va_start(ap, fmt);
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len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
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va_end(ap);
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if (len < 0)
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die("your vsnprintf is broken");
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if (len > strbuf_avail(sb)) {
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strbuf_grow(sb, len);
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va_start(ap, fmt);
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len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
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va_end(ap);
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if (len > strbuf_avail(sb)) {
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die("this should not happen, your vsnprintf is broken");
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}
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}
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strbuf_setlen(sb, sb->len + len);
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}
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ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
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{
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size_t oldlen = sb->len;
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size_t oldalloc = sb->alloc;
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strbuf_grow(sb, hint ? hint : 8192);
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for (;;) {
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ssize_t cnt;
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cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
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if (cnt < 0) {
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if (oldalloc == 0)
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strbuf_release(sb);
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else
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strbuf_setlen(sb, oldlen);
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return -1;
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}
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if (!cnt)
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break;
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sb->len += cnt;
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strbuf_grow(sb, 8192);
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}
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sb->buf[sb->len] = '\0';
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return sb->len - oldlen;
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}
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