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[PATCH 05/18] posix: Rewrite to use struct scratch_buffer instead of extend_alloca
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Cc: Florian Weimer <fweimer at redhat dot com>
- Date: Fri, 11 Aug 2017 11:50:31 -0300
- Subject: [PATCH 05/18] posix: Rewrite to use struct scratch_buffer instead of extend_alloca
- Authentication-results: sourceware.org; auth=none
- References: <1502463044-4042-1-git-send-email-adhemerval.zanella@linaro.org>
From: Florian Weimer <fweimer@redhat.com>
This patch removes a lot of boilerplate code to manager buffers for
getpwnam_r.
Checked on x86_64-linux-gnu.
[BZ #18023]
* posix/glob.c (glob): Use struct scratch_buffer instead of
extend_alloca.
---
posix/glob.c | 147 +++++++++++------------------------------------------------
1 file changed, 26 insertions(+), 121 deletions(-)
diff --git a/posix/glob.c b/posix/glob.c
index 7b6b426..99e9c54 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -89,12 +89,8 @@
#include <fnmatch.h>
#include <glob_internal.h>
+#include <scratch_buffer.h>
-#ifdef _SC_GETPW_R_SIZE_MAX
-# define GETPW_R_SIZE_MAX() sysconf (_SC_GETPW_R_SIZE_MAX)
-#else
-# define GETPW_R_SIZE_MAX() (-1)
-#endif
#ifdef _SC_LOGIN_NAME_MAX
# define GET_LOGIN_NAME_MAX() sysconf (_SC_LOGIN_NAME_MAX)
#else
@@ -696,97 +692,43 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
if (success)
{
struct passwd *p;
- char *malloc_pwtmpbuf = NULL;
- char *pwtmpbuf;
# if defined HAVE_GETPWNAM_R || defined _LIBC
- long int pwbuflenmax = GETPW_R_SIZE_MAX ();
- size_t pwbuflen = pwbuflenmax;
struct passwd pwbuf;
int save = errno;
+ struct scratch_buffer pwtmpbuf;
+ scratch_buffer_init (&pwtmpbuf);
-# ifndef _LIBC
- if (! (0 < pwbuflenmax && pwbuflenmax <= SIZE_MAX))
- /* `sysconf' does not support _SC_GETPW_R_SIZE_MAX.
- Try a moderate value. */
- pwbuflen = 1024;
-# endif
- if (glob_use_alloca (alloca_used, pwbuflen))
- pwtmpbuf = alloca_account (pwbuflen, alloca_used);
- else
- {
- pwtmpbuf = malloc (pwbuflen);
- if (pwtmpbuf == NULL)
- {
- if (__glibc_unlikely (malloc_name))
- free (name);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_pwtmpbuf = pwtmpbuf;
- }
-
- while (getpwnam_r (name, &pwbuf, pwtmpbuf, pwbuflen, &p)
+ while (getpwnam_r (name, &pwbuf,
+ pwtmpbuf.data, pwtmpbuf.length, &p)
!= 0)
{
- size_t newlen;
- bool v;
if (errno != ERANGE)
{
p = NULL;
break;
}
- v = size_add_wrapv (pwbuflen, pwbuflen, &newlen);
- if (!v && malloc_pwtmpbuf == NULL
- && glob_use_alloca (alloca_used, newlen))
- pwtmpbuf = extend_alloca_account (pwtmpbuf, pwbuflen,
- newlen, alloca_used);
- else
+ if (!scratch_buffer_grow (&pwtmpbuf))
{
- char *newp = (v ? NULL
- : realloc (malloc_pwtmpbuf, newlen));
- if (newp == NULL)
- {
- free (malloc_pwtmpbuf);
- if (__glibc_unlikely (malloc_name))
- free (name);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_pwtmpbuf = pwtmpbuf = newp;
+ retval = GLOB_NOSPACE;
+ goto out;
}
- pwbuflen = newlen;
__set_errno (save);
}
# else
- p = getpwnam (name);
+ p = getpwnam (pwtmpbuf.data);
# endif
- if (__glibc_unlikely (malloc_name))
- free (name);
if (p != NULL)
{
- if (malloc_pwtmpbuf == NULL)
- home_dir = p->pw_dir;
- else
+ home_dir = strdup (p->pw_dir);
+ malloc_home_dir = 1;
+ if (home_dir == NULL)
{
- size_t home_dir_len = strlen (p->pw_dir) + 1;
- if (glob_use_alloca (alloca_used, home_dir_len))
- home_dir = alloca_account (home_dir_len,
- alloca_used);
- else
- {
- home_dir = malloc (home_dir_len);
- if (home_dir == NULL)
- {
- free (pwtmpbuf);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_home_dir = 1;
- }
- memcpy (home_dir, p->pw_dir, home_dir_len);
+ scratch_buffer_free (&pwtmpbuf);
+ retval = GLOB_NOSPACE;
+ goto out;
}
}
- free (malloc_pwtmpbuf);
+ scratch_buffer_free (&pwtmpbuf);
}
else
{
@@ -924,59 +866,25 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
/* Look up specific user's home directory. */
{
struct passwd *p;
- char *malloc_pwtmpbuf = NULL;
+ struct scratch_buffer pwtmpbuf;
+ scratch_buffer_init (&pwtmpbuf);
+
# if defined HAVE_GETPWNAM_R || defined _LIBC
- long int buflenmax = GETPW_R_SIZE_MAX ();
- size_t buflen = buflenmax;
- char *pwtmpbuf;
struct passwd pwbuf;
int save = errno;
-# ifndef _LIBC
- if (! (0 <= buflenmax && buflenmax <= SIZE_MAX))
- /* Perhaps 'sysconf' does not support _SC_GETPW_R_SIZE_MAX. Try a
- moderate value. */
- buflen = 1024;
-# endif
- if (glob_use_alloca (alloca_used, buflen))
- pwtmpbuf = alloca_account (buflen, alloca_used);
- else
- {
- pwtmpbuf = malloc (buflen);
- if (pwtmpbuf == NULL)
- {
- nomem_getpw:
- if (__glibc_unlikely (malloc_user_name))
- free (user_name);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_pwtmpbuf = pwtmpbuf;
- }
-
- while (getpwnam_r (user_name, &pwbuf, pwtmpbuf, buflen, &p) != 0)
+ while (getpwnam_r (user_name, &pwbuf,
+ pwtmpbuf.data, pwtmpbuf.length, &p) != 0)
{
- size_t newlen;
- bool v;
if (errno != ERANGE)
{
p = NULL;
break;
}
- v = size_add_wrapv (buflen, buflen, &newlen);
- if (!v && malloc_pwtmpbuf == NULL
- && glob_use_alloca (alloca_used, newlen))
- pwtmpbuf = extend_alloca_account (pwtmpbuf, buflen,
- newlen, alloca_used);
- else
+ if (!scratch_buffer_grow (&pwtmpbuf))
{
- char *newp = v ? NULL : realloc (malloc_pwtmpbuf, newlen);
- if (newp == NULL)
- {
- free (malloc_pwtmpbuf);
- goto nomem_getpw;
- }
- malloc_pwtmpbuf = pwtmpbuf = newp;
+ retval = GLOB_NOSPACE;
+ goto out;
}
__set_errno (save);
}
@@ -1005,7 +913,7 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
dirname = malloc (home_len + rest_len + 1);
if (dirname == NULL)
{
- free (malloc_pwtmpbuf);
+ scratch_buffer_free (&pwtmpbuf);
retval = GLOB_NOSPACE;
goto out;
}
@@ -1016,13 +924,9 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
dirlen = home_len + rest_len;
dirname_modified = 1;
-
- free (malloc_pwtmpbuf);
}
else
{
- free (malloc_pwtmpbuf);
-
if (flags & GLOB_TILDE_CHECK)
{
/* We have to regard it as an error if we cannot find the
@@ -1031,6 +935,7 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
goto out;
}
}
+ scratch_buffer_free (&pwtmpbuf);
}
}
# endif /* Not Amiga && not WINDOWS32. */
--
2.7.4