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-rw-r--r--ldso/dynlink.c9
-rw-r--r--src/internal/malloc_impl.h3
-rw-r--r--src/malloc/malloc.c13
-rw-r--r--src/malloc/memalign.c2
4 files changed, 22 insertions, 5 deletions
diff --git a/ldso/dynlink.c b/ldso/dynlink.c
index 63e7b81f..cea5f452 100644
--- a/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -134,6 +134,9 @@ static struct dso *const nodeps_dummy;
struct debug *_dl_debug_addr = &debug;
__attribute__((__visibility__("hidden")))
+extern int __malloc_replaced;
+
+__attribute__((__visibility__("hidden")))
void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
__attribute__((__visibility__("hidden")))
@@ -1691,6 +1694,12 @@ _Noreturn void __dls3(size_t *sp)
if (ldso_fail) _exit(127);
if (ldd_mode) _exit(0);
+ /* Determine if malloc was interposed by a replacement implementation
+ * so that calloc and the memalign family can harden against the
+ * possibility of incomplete replacement. */
+ if (find_sym(head, "malloc", 1).dso != &ldso)
+ __malloc_replaced = 1;
+
/* Switch to runtime mode: any further failures in the dynamic
* linker are a reportable failure rather than a fatal startup
* error. */
diff --git a/src/internal/malloc_impl.h b/src/internal/malloc_impl.h
index 4c4a4b46..5d025b06 100644
--- a/src/internal/malloc_impl.h
+++ b/src/internal/malloc_impl.h
@@ -39,4 +39,7 @@ struct bin {
__attribute__((__visibility__("hidden")))
void __bin_chunk(struct chunk *);
+__attribute__((__visibility__("hidden")))
+extern int __malloc_replaced;
+
#endif
diff --git a/src/malloc/malloc.c b/src/malloc/malloc.c
index 239ab9c6..d72883e1 100644
--- a/src/malloc/malloc.c
+++ b/src/malloc/malloc.c
@@ -20,6 +20,8 @@ static struct {
volatile int free_lock[2];
} mal;
+int __malloc_replaced;
+
/* Synchronization tools */
static inline void lock(volatile int *lk)
@@ -356,10 +358,13 @@ void *calloc(size_t m, size_t n)
}
n *= m;
void *p = malloc(n);
- if (!p || IS_MMAPPED(MEM_TO_CHUNK(p)))
- return p;
- if (n >= PAGE_SIZE)
- n = mal0_clear(p, PAGE_SIZE, n);
+ if (!p) return p;
+ if (!__malloc_replaced) {
+ if (IS_MMAPPED(MEM_TO_CHUNK(p)))
+ return p;
+ if (n >= PAGE_SIZE)
+ n = mal0_clear(p, PAGE_SIZE, n);
+ }
return memset(p, 0, n);
}
diff --git a/src/malloc/memalign.c b/src/malloc/memalign.c
index 7246a99b..8a6152f4 100644
--- a/src/malloc/memalign.c
+++ b/src/malloc/memalign.c
@@ -13,7 +13,7 @@ void *__memalign(size_t align, size_t len)
return 0;
}
- if (len > SIZE_MAX - align) {
+ if (len > SIZE_MAX - align || __malloc_replaced) {
errno = ENOMEM;
return 0;
}