From e944df5cf7490d76a2253e48e086b64eb496a05b Mon Sep 17 00:00:00 2001
From: Tim Wickberg <tim@schedmd.com>
Date: Tue, 4 Sep 2018 18:49:22 -0600
Subject: [PATCH] Add xcalloc() macro and convert slurm_xmalloc into
slurm_xcalloc() function.
Use this instead of handling the multiplication ourselves. This lets us
check for potential problems from integer overflow, and IMNSHO makes the
code look a lot tidier.
Rework xmalloc() and xmalloc_nz() macros in terms of slurm_xcalloc().
Bug 6310.
---
src/common/xmalloc.c | 27 +++++++++++++++++++++------
src/common/xmalloc.h | 9 ++++++---
2 files changed, 27 insertions(+), 9 deletions(-)
diff --git a/src/common/xmalloc.c b/src/common/xmalloc.c
index 37bcbfa1aef..d32fd538346 100644
--- a/src/common/xmalloc.c
+++ b/src/common/xmalloc.c
@@ -43,6 +43,7 @@
#include <errno.h>
#include <pthread.h>
+#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -71,16 +72,31 @@ static void malloc_assert_failed(char *, const char *, int,
* clear (IN) initialize to zero
* RETURN pointer to allocate heap space
*/
-void *slurm_xmalloc(size_t size, bool clear,
+void *slurm_xcalloc(size_t count, size_t size, bool clear,
const char *file, int line, const char *func)
{
- void *new;
+ size_t total_size;
size_t *p;
- size_t total_size = size + 2 * sizeof(size_t);
- if (size <= 0)
+ if (!size || !count)
return NULL;
+ /*
+ * Detect overflow of the size calculation and abort().
+ * Ensure there is sufficient space for the two header words used to
+ * store the magic value and the allocation length by dividing by two,
+ * and because on 32-bit systems, if a 2GB allocation request isn't
+ * sufficient (which would attempt to allocate 2GB + 8Bytes),
+ * then we're going to run into other problems anyways.
+ * (And on 64-bit, if a 2EB + 16Bytes request isn't sufficient...)
+ */
+ if ((count != 1) && (count > SIZE_MAX / size / 4)) {
+ log_oom(file, line, func);
+ abort();
+ }
+
+ total_size = count * size + 2 * sizeof(size_t);
+
if (clear)
p = calloc(1, total_size);
else
@@ -93,8 +109,7 @@ void *slurm_xmalloc(size_t size, bool clear,
p[0] = XMALLOC_MAGIC; /* add "secret" magic cookie */
p[1] = size; /* store size in buffer */
- new = &p[2];
- return new;
+ return &p[2];
}
/*
diff --git a/src/common/xmalloc.h b/src/common/xmalloc.h
index a4c96bd127e..89d4949b48d 100644
--- a/src/common/xmalloc.h
+++ b/src/common/xmalloc.h
@@ -71,11 +71,14 @@
#include <stdbool.h>
#include <sys/types.h>
+#define xcalloc(__cnt, __sz) \
+ slurm_xcalloc(__cnt, __sz, true, __FILE__, __LINE__, __func__)
+
#define xmalloc(__sz) \
- slurm_xmalloc (__sz, true, __FILE__, __LINE__, __func__)
+ slurm_xcalloc(1, __sz, true, __FILE__, __LINE__, __func__)
#define xmalloc_nz(__sz) \
- slurm_xmalloc (__sz, false, __FILE__, __LINE__, __func__)
+ slurm_xcalloc(1, __sz, false, __FILE__, __LINE__, __func__)
#define xfree(__p) \
slurm_xfree((void **)&(__p), __FILE__, __LINE__, __func__)
@@ -91,7 +94,7 @@
#define xsize(__p) \
slurm_xsize((void *)__p, __FILE__, __LINE__, __func__)
-void *slurm_xmalloc(size_t, bool, const char *, int, const char *);
+void *slurm_xcalloc(size_t, size_t, bool, const char *, int, const char *);
void slurm_xfree(void **, const char *, int, const char *);
void *slurm_xrealloc(void **, size_t, bool, const char *, int, const char *);
size_t slurm_xsize(void *, const char *, int, const char *);
--
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