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[PATCH 13/25] nscd_getgr_r: Use struct scratch_buffer instead of extend_alloca
- From: Florian Weimer <fweimer at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Sun, 1 Mar 2015 18:45:17 +0100
- Subject: [PATCH 13/25] nscd_getgr_r: Use struct scratch_buffer instead of extend_alloca
- Authentication-results: sourceware.org; auth=none
- References: <cover dot 1425285061 dot git dot fweimer at redhat dot com>
The lack of alloca accounting means that the old code could run out of
stack space if multiple retries are needed.
---
nscd/nscd_getgr_r.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/nscd/nscd_getgr_r.c b/nscd/nscd_getgr_r.c
index 7e45ee5..d08b73f 100644
--- a/nscd/nscd_getgr_r.c
+++ b/nscd/nscd_getgr_r.c
@@ -31,6 +31,7 @@
#include <sys/un.h>
#include <not-cancel.h>
#include <_itoa.h>
+#include <scratch_buffer.h>
#include "nscd-client.h"
#include "nscd_proto.h"
@@ -89,7 +90,8 @@ nscd_getgr_r (const char *key, size_t keylen, request_type type,
int gc_cycle;
int nretries = 0;
const uint32_t *len = NULL;
- size_t lensize = 0;
+ struct scratch_buffer lenbuf;
+ scratch_buffer_init (&lenbuf);
/* If the mapping is available, try to search there instead of
communicating with the nscd. */
@@ -200,14 +202,10 @@ nscd_getgr_r (const char *key, size_t keylen, request_type type,
else
{
/* Allocate array to store lengths. */
- if (lensize == 0)
- {
- lensize = gr_resp.gr_mem_cnt * sizeof (uint32_t);
- len = (uint32_t *) alloca (lensize);
- }
- else if (gr_resp.gr_mem_cnt * sizeof (uint32_t) > lensize)
- len = extend_alloca (len, lensize,
- gr_resp.gr_mem_cnt * sizeof (uint32_t));
+ if (!scratch_buffer_set_array_size
+ (&lenbuf, gr_resp.gr_mem_cnt, sizeof (uint32_t)))
+ goto out_close;
+ len = lenbuf.data;
vec[0].iov_base = (void *) len;
vec[0].iov_len = gr_resp.gr_mem_cnt * sizeof (uint32_t);
@@ -326,5 +324,7 @@ nscd_getgr_r (const char *key, size_t keylen, request_type type,
goto retry;
}
+ scratch_buffer_free (&lenbuf);
+
return retval;
}
--
2.1.0