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authorLibravatar Junio C Hamano <gitster@pobox.com>2016-09-29 16:49:44 -0700
committerLibravatar Junio C Hamano <gitster@pobox.com>2016-09-29 16:49:45 -0700
commit300e95f7df240a0f6efea09d5e21fcc350e5ce83 (patch)
tree0b2a114656894e4177030ad6019e5581b3981d4c
parentMerge branch 'nd/checkout-disambiguation' into maint (diff)
parentregex: use regexec_buf() (diff)
downloadtgif-300e95f7df240a0f6efea09d5e21fcc350e5ce83.tar.xz
Merge branch 'js/regexec-buf' into maint
Some codepaths in "git diff" used regexec(3) on a buffer that was mmap(2)ed, which may not have a terminating NUL, leading to a read beyond the end of the mapped region. This was fixed by introducing a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND extension. * js/regexec-buf: regex: use regexec_buf() regex: add regexec_buf() that can work on a non NUL-terminated string regex: -G<pattern> feeds a non NUL-terminated string to regexec() and fails
-rw-r--r--Makefile3
-rw-r--r--diff.c3
-rw-r--r--diffcore-pickaxe.c18
-rw-r--r--git-compat-util.h13
-rw-r--r--grep.c14
-rwxr-xr-xt/t4062-diff-pickaxe.sh22
-rw-r--r--xdiff-interface.c13
7 files changed, 53 insertions, 33 deletions
diff --git a/Makefile b/Makefile
index 7f184923dd..7a36af8665 100644
--- a/Makefile
+++ b/Makefile
@@ -301,7 +301,8 @@ all::
# crashes due to allocation and free working on different 'heaps'.
# It's defined automatically if USE_NED_ALLOCATOR is set.
#
-# Define NO_REGEX if you have no or inferior regex support in your C library.
+# Define NO_REGEX if your C library lacks regex support with REG_STARTEND
+# feature.
#
# Define HAVE_DEV_TTY if your system can open /dev/tty to interact with the
# user.
diff --git a/diff.c b/diff.c
index cc8e81290a..7a4309397c 100644
--- a/diff.c
+++ b/diff.c
@@ -949,7 +949,8 @@ static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
{
if (word_regex && *begin < buffer->size) {
regmatch_t match[1];
- if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
+ if (!regexec_buf(word_regex, buffer->ptr + *begin,
+ buffer->size - *begin, 1, match, 0)) {
char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
'\n', match[0].rm_eo - match[0].rm_so);
*end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index 55067cab6c..9795ca1c15 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -23,7 +23,6 @@ static void diffgrep_consume(void *priv, char *line, unsigned long len)
{
struct diffgrep_cb *data = priv;
regmatch_t regmatch;
- int hold;
if (line[0] != '+' && line[0] != '-')
return;
@@ -33,11 +32,8 @@ static void diffgrep_consume(void *priv, char *line, unsigned long len)
* caller early.
*/
return;
- /* Yuck -- line ought to be "const char *"! */
- hold = line[len];
- line[len] = '\0';
- data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
- line[len] = hold;
+ data->hit = !regexec_buf(data->regexp, line + 1, len - 1, 1,
+ &regmatch, 0);
}
static int diff_grep(mmfile_t *one, mmfile_t *two,
@@ -50,9 +46,11 @@ static int diff_grep(mmfile_t *one, mmfile_t *two,
xdemitconf_t xecfg;
if (!one)
- return !regexec(regexp, two->ptr, 1, &regmatch, 0);
+ return !regexec_buf(regexp, two->ptr, two->size,
+ 1, &regmatch, 0);
if (!two)
- return !regexec(regexp, one->ptr, 1, &regmatch, 0);
+ return !regexec_buf(regexp, one->ptr, one->size,
+ 1, &regmatch, 0);
/*
* We have both sides; need to run textual diff and see if
@@ -83,8 +81,8 @@ static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws)
regmatch_t regmatch;
int flags = 0;
- assert(data[sz] == '\0');
- while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
+ while (*data &&
+ !regexec_buf(regexp, data, sz, 1, &regmatch, flags)) {
flags |= REG_NOTBOL;
data += regmatch.rm_eo;
if (*data && regmatch.rm_so == regmatch.rm_eo)
diff --git a/git-compat-util.h b/git-compat-util.h
index 68615b1a6a..2c949983dc 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -974,6 +974,19 @@ void git_qsort(void *base, size_t nmemb, size_t size,
#define qsort git_qsort
#endif
+#ifndef REG_STARTEND
+#error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
+#endif
+
+static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
+ size_t nmatch, regmatch_t pmatch[], int eflags)
+{
+ assert(nmatch > 0 && pmatch);
+ pmatch[0].rm_so = 0;
+ pmatch[0].rm_eo = size;
+ return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
+}
+
#ifndef DIR_HAS_BSD_GROUP_SEMANTICS
# define FORCE_DIR_SET_GID S_ISGID
#else
diff --git a/grep.c b/grep.c
index d7d00b87cb..1194d35b5d 100644
--- a/grep.c
+++ b/grep.c
@@ -898,17 +898,6 @@ static int fixmatch(struct grep_pat *p, char *line, char *eol,
}
}
-static int regmatch(const regex_t *preg, char *line, char *eol,
- regmatch_t *match, int eflags)
-{
-#ifdef REG_STARTEND
- match->rm_so = 0;
- match->rm_eo = eol - line;
- eflags |= REG_STARTEND;
-#endif
- return regexec(preg, line, 1, match, eflags);
-}
-
static int patmatch(struct grep_pat *p, char *line, char *eol,
regmatch_t *match, int eflags)
{
@@ -919,7 +908,8 @@ static int patmatch(struct grep_pat *p, char *line, char *eol,
else if (p->pcre_regexp)
hit = !pcrematch(p, line, eol, match, eflags);
else
- hit = !regmatch(&p->regexp, line, eol, match, eflags);
+ hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
+ eflags);
return hit;
}
diff --git a/t/t4062-diff-pickaxe.sh b/t/t4062-diff-pickaxe.sh
new file mode 100755
index 0000000000..f0bf50bda7
--- /dev/null
+++ b/t/t4062-diff-pickaxe.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# Copyright (c) 2016 Johannes Schindelin
+#
+
+test_description='Pickaxe options'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+ test_commit initial &&
+ printf "%04096d" 0 >4096-zeroes.txt &&
+ git add 4096-zeroes.txt &&
+ test_tick &&
+ git commit -m "A 4k file"
+'
+test_expect_success '-G matches' '
+ git diff --name-only -G "^0{4096}$" HEAD^ >out &&
+ test 4096-zeroes.txt = "$(cat out)"
+'
+
+test_done
diff --git a/xdiff-interface.c b/xdiff-interface.c
index f34ea762e4..50702a215d 100644
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -214,11 +214,10 @@ struct ff_regs {
static long ff_regexp(const char *line, long len,
char *buffer, long buffer_size, void *priv)
{
- char *line_buffer;
struct ff_regs *regs = priv;
regmatch_t pmatch[2];
int i;
- int result = -1;
+ int result;
/* Exclude terminating newline (and cr) from matching */
if (len > 0 && line[len-1] == '\n') {
@@ -228,18 +227,16 @@ static long ff_regexp(const char *line, long len,
len--;
}
- line_buffer = xstrndup(line, len); /* make NUL terminated */
-
for (i = 0; i < regs->nr; i++) {
struct ff_reg *reg = regs->array + i;
- if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
+ if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
if (reg->negate)
- goto fail;
+ return -1;
break;
}
}
if (regs->nr <= i)
- goto fail;
+ return -1;
i = pmatch[1].rm_so >= 0 ? 1 : 0;
line += pmatch[i].rm_so;
result = pmatch[i].rm_eo - pmatch[i].rm_so;
@@ -248,8 +245,6 @@ static long ff_regexp(const char *line, long len,
while (result > 0 && (isspace(line[result - 1])))
result--;
memcpy(buffer, line, result);
- fail:
- free(line_buffer);
return result;
}