[19/25] getlogin_r (Linux variant): Switch to struct scratch_buffer
Commit Message
This corrects the alloca accounting as a side effect. It was not off
if extend_alloca failed to merge allocations.
---
sysdeps/unix/sysv/linux/getlogin_r.c | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)
@@ -18,6 +18,7 @@
#include <pwd.h>
#include <unistd.h>
#include <not-cancel.h>
+#include <scratch_buffer.h>
#define STATIC static
static int getlogin_r_fd0 (char *name, size_t namesize);
@@ -56,28 +57,19 @@ __getlogin_r_loginuid (name, namesize)
endp == uidbuf || *endp != '\0'))
return -1;
- size_t buflen = 1024;
- char *buf = alloca (buflen);
- bool use_malloc = false;
struct passwd pwd;
struct passwd *tpwd;
int result = 0;
int res;
+ struct scratch_buffer tmpbuf;
+ scratch_buffer_init (&tmpbuf);
- while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) == ERANGE)
- if (__libc_use_alloca (2 * buflen))
- buf = extend_alloca (buf, buflen, 2 * buflen);
- else
+ while ((res = __getpwuid_r (uid, &pwd,
+ tmpbuf.data, tmpbuf.length, &tpwd)) == ERANGE)
+ if (!scratch_buffer_grow (&tmpbuf))
{
- buflen *= 2;
- char *newp = realloc (use_malloc ? buf : NULL, buflen);
- if (newp == NULL)
- {
- result = ENOMEM;
- goto out;
- }
- buf = newp;
- use_malloc = true;
+ result = ENOMEM;
+ goto out;
}
if (res != 0 || tpwd == NULL)
@@ -97,9 +89,7 @@ __getlogin_r_loginuid (name, namesize)
memcpy (name, pwd.pw_name, needed);
out:
- if (use_malloc)
- free (buf);
-
+ scratch_buffer_free (&tmpbuf);
return result;
}