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* sysdeps/unix/sysv/linux/getsysstats.c (next_line): Make sure there

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are always at least 4 bytes in the returned line.

2009-04-15  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Check
	__libc_use_alloca (8192), if the stack is too small use 512 bytes
	instead of 8K.  Stop searching in /proc/stat after hitting first
	line not starting with cpu.
	(next_line): Truncate too long
	lines at buffer size * 3/4 instead of pretending there were line
	breaks inside of large lines.
This commit is contained in:
Ulrich Drepper
2009-04-15 15:57:47 +00:00
parent ae650a41ef
commit 6a3d03ff58
2 changed files with 51 additions and 4 deletions
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15
ChangeLog
View File

@ -1,3 +1,18 @@
2009-04-15 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/getsysstats.c (next_line): Make sure there
are always at least 4 bytes in the returned line.
2009-04-15 Jakub Jelinek <jakub@redhat.com>
* sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Check
__libc_use_alloca (8192), if the stack is too small use 512 bytes
instead of 8K. Stop searching in /proc/stat after hitting first
line not starting with cpu.
(next_line): Truncate too long
lines at buffer size * 3/4 instead of pretending there were line
breaks inside of large lines.
2009-04-14 Ulrich Drepper <drepper@redhat.com> 2009-04-14 Ulrich Drepper <drepper@redhat.com>
* sysdeps/x86_64/mp_clz_tab.c: New file. * sysdeps/x86_64/mp_clz_tab.c: New file.

40
sysdeps/unix/sysv/linux/getsysstats.c
View File

@ -93,15 +93,42 @@ next_line (int fd, char *const buffer, char **cp, char **re,
return NULL; return NULL;
*re += n; *re += n;
nl = memchr (*cp, '\n', *re - *cp);
while (nl == NULL && *re == buffer_end)
{
/* Truncate too long lines. */
*re = buffer + 3 * (buffer_end - buffer) / 4;
n = read_not_cancel (fd, *re, buffer_end - *re);
if (n < 0)
return NULL;
nl = memchr (*re, '\n', n);
**re = '\n';
*re += n;
}
} }
else
nl = memchr (*cp, '\n', *re - *cp);
res = *cp; res = *cp;
nl = memchr (*cp, '\n', *re - *cp);
} }
if (nl == NULL) if (nl == NULL)
nl = *re - 1; nl = *re - 1;
} }
else if (nl + 5 >= *re)
{
memmove (buffer, nl, *re - nl);
*re = buffer + (*re - nl);
nl = *cp = buffer;
ssize_t n = read_not_cancel (fd, *re, buffer_end - *re);
if (n < 0)
return NULL;
*re += n;
}
*cp = nl + 1; *cp = nl + 1;
assert (*cp <= *re); assert (*cp <= *re);
@ -115,8 +142,9 @@ __get_nprocs ()
{ {
/* XXX Here will come a test for the new system call. */ /* XXX Here will come a test for the new system call. */
char buffer[8192]; const size_t buffer_size = __libc_use_alloca (8192) ? 8192 : 512;
char *const buffer_end = buffer + sizeof (buffer); char *buffer = alloca (buffer_size);
char *buffer_end = buffer + buffer_size;
char *cp = buffer_end; char *cp = buffer_end;
char *re = buffer_end; char *re = buffer_end;
int result = 1; int result = 1;
@ -134,7 +162,11 @@ __get_nprocs ()
char *l; char *l;
while ((l = next_line (fd, buffer, &cp, &re, buffer_end)) != NULL) while ((l = next_line (fd, buffer, &cp, &re, buffer_end)) != NULL)
if (strncmp (l, "cpu", 3) == 0 && isdigit (l[3])) /* The current format of /proc/stat has all the cpu* entries
at the front. We assume here that stays this way. */
if (strncmp (l, "cpu", 3) != 0)
break;
else if (isdigit (l[3]))
++result; ++result;
close_not_cancel_no_status (fd); close_not_cancel_no_status (fd);