[PATCH v3 2/3] malloc: Annotate allocator for valgrind
Sean Anderson
seanga2 at gmail.com
Wed Mar 23 19:04:49 CET 2022
This annotates malloc and friends so that valgrind can track the heap. To
do this, we need to follow a few rules:
* Call VALGRIND_MALLOCLIKE_BLOCK whenever we malloc something
* Call VALGRIND_FREELIKE_BLOCK whenever we free something (generally after
we have done our bookkeeping)
* Call VALGRIND_RESIZEINPLACE_BLOCK whenever we change the size of an
allocation. We don't record the original request size of a block, and
neither does valgrind. For this reason, we pretend that the old size of
the allocation was for 0 bytes. This marks the whole allocaton as
undefined, so in order to mark all bits correctly, we must make the whole
new allocation defined with VALGRIND_MAKE_MEM_DEFINED. This may cause us
to miss some invalid reads, but there is no way to detect these without
recording the original size of the allocation.
In addition to the above, dlmalloc itself tends to make a lot of accesses
which we know are safe, but which would be unsafe outside of dlmalloc. For
this reason, we provide a suppression file which ignores errors ocurring in
dlmalloc.c
Signed-off-by: Sean Anderson <seanga2 at gmail.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
Changes in v3:
- Fix an additional rEALLOc branch missing VALGRIND_RESIZEINPLACE_BLOCK
Changes in v2:
- Fix one branch of rEALLOc missing a VALGRIND_*_BLOCK call
- Add some additional suppressions for cALLOc and rEALLOc
- Simplify calloc clearing logic
common/dlmalloc.c | 31 +++++++++++++++++++++++-
common/malloc_simple.c | 10 ++++++++
include/malloc.h | 4 ++++
scripts/u-boot.supp | 53 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 97 insertions(+), 1 deletion(-)
create mode 100644 scripts/u-boot.supp
diff --git a/common/dlmalloc.c b/common/dlmalloc.c
index 11729e8c85..f48cd2a333 100644
--- a/common/dlmalloc.c
+++ b/common/dlmalloc.c
@@ -18,6 +18,7 @@
#include <malloc.h>
#include <asm/io.h>
+#include <valgrind/memcheck.h>
#ifdef DEBUG
#if __STD_C
@@ -1339,6 +1340,7 @@ Void_t* mALLOc(bytes) size_t bytes;
unlink(victim, bck, fwd);
set_inuse_bit_at_offset(victim, victim_size);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
@@ -1366,6 +1368,7 @@ Void_t* mALLOc(bytes) size_t bytes;
unlink(victim, bck, fwd);
set_inuse_bit_at_offset(victim, victim_size);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
}
@@ -1389,6 +1392,7 @@ Void_t* mALLOc(bytes) size_t bytes;
set_head(remainder, remainder_size | PREV_INUSE);
set_foot(remainder, remainder_size);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
@@ -1398,6 +1402,7 @@ Void_t* mALLOc(bytes) size_t bytes;
{
set_inuse_bit_at_offset(victim, victim_size);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
@@ -1453,6 +1458,7 @@ Void_t* mALLOc(bytes) size_t bytes;
set_head(remainder, remainder_size | PREV_INUSE);
set_foot(remainder, remainder_size);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
@@ -1461,6 +1467,7 @@ Void_t* mALLOc(bytes) size_t bytes;
set_inuse_bit_at_offset(victim, victim_size);
unlink(victim, bck, fwd);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
@@ -1509,6 +1516,7 @@ Void_t* mALLOc(bytes) size_t bytes;
/* If big and would otherwise need to extend, try to use mmap instead */
if ((unsigned long)nb >= (unsigned long)mmap_threshold &&
(victim = mmap_chunk(nb)))
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
#endif
@@ -1523,6 +1531,7 @@ Void_t* mALLOc(bytes) size_t bytes;
top = chunk_at_offset(victim, nb);
set_head(top, remainder_size | PREV_INUSE);
check_malloced_chunk(victim, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(victim), bytes, SIZE_SZ, false);
return chunk2mem(victim);
}
@@ -1571,8 +1580,10 @@ void fREe(mem) Void_t* mem;
#if CONFIG_VAL(SYS_MALLOC_F_LEN)
/* free() is a no-op - all the memory will be freed on relocation */
- if (!(gd->flags & GD_FLG_FULL_MALLOC_INIT))
+ if (!(gd->flags & GD_FLG_FULL_MALLOC_INIT)) {
+ VALGRIND_FREELIKE_BLOCK(mem, SIZE_SZ);
return;
+ }
#endif
if (mem == NULL) /* free(0) has no effect */
@@ -1594,6 +1605,7 @@ void fREe(mem) Void_t* mem;
sz = hd & ~PREV_INUSE;
next = chunk_at_offset(p, sz);
nextsz = chunksize(next);
+ VALGRIND_FREELIKE_BLOCK(mem, SIZE_SZ);
if (next == top) /* merge with top */
{
@@ -1782,6 +1794,8 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
top = chunk_at_offset(oldp, nb);
set_head(top, (newsize - nb) | PREV_INUSE);
set_head_size(oldp, nb);
+ VALGRIND_RESIZEINPLACE_BLOCK(chunk2mem(oldp), 0, bytes, SIZE_SZ);
+ VALGRIND_MAKE_MEM_DEFINED(chunk2mem(oldp), bytes);
return chunk2mem(oldp);
}
}
@@ -1791,6 +1805,8 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
{
unlink(next, bck, fwd);
newsize += nextsize;
+ VALGRIND_RESIZEINPLACE_BLOCK(chunk2mem(oldp), 0, bytes, SIZE_SZ);
+ VALGRIND_MAKE_MEM_DEFINED(chunk2mem(oldp), bytes);
goto split;
}
}
@@ -1820,10 +1836,12 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
newp = prev;
newsize += prevsize + nextsize;
newmem = chunk2mem(newp);
+ VALGRIND_MALLOCLIKE_BLOCK(newmem, bytes, SIZE_SZ, false);
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
top = chunk_at_offset(newp, nb);
set_head(top, (newsize - nb) | PREV_INUSE);
set_head_size(newp, nb);
+ VALGRIND_FREELIKE_BLOCK(oldmem, SIZE_SZ);
return newmem;
}
}
@@ -1836,6 +1854,7 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
newp = prev;
newsize += nextsize + prevsize;
newmem = chunk2mem(newp);
+ VALGRIND_MALLOCLIKE_BLOCK(newmem, bytes, SIZE_SZ, false);
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
goto split;
}
@@ -1848,6 +1867,7 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
newp = prev;
newsize += prevsize;
newmem = chunk2mem(newp);
+ VALGRIND_MALLOCLIKE_BLOCK(newmem, bytes, SIZE_SZ, false);
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
goto split;
}
@@ -1874,6 +1894,9 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
fREe(oldmem);
return newmem;
+ } else {
+ VALGRIND_RESIZEINPLACE_BLOCK(oldmem, 0, bytes, SIZE_SZ);
+ VALGRIND_MAKE_MEM_DEFINED(oldmem, bytes);
}
@@ -1886,6 +1909,8 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
set_head_size(newp, nb);
set_head(remainder, remainder_size | PREV_INUSE);
set_inuse_bit_at_offset(remainder, remainder_size);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(remainder), remainder_size, SIZE_SZ,
+ false);
fREe(chunk2mem(remainder)); /* let free() deal with it */
}
else
@@ -2043,6 +2068,7 @@ Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
set_head_size(p, leadsize);
fREe(chunk2mem(p));
p = newp;
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(p), bytes, SIZE_SZ, false);
assert (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0);
}
@@ -2056,6 +2082,8 @@ Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
remainder = chunk_at_offset(p, nb);
set_head(remainder, remainder_size | PREV_INUSE);
set_head_size(p, nb);
+ VALGRIND_MALLOCLIKE_BLOCK(chunk2mem(remainder), remainder_size, SIZE_SZ,
+ false);
fREe(chunk2mem(remainder));
}
@@ -2159,6 +2187,7 @@ Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size;
#endif
MALLOC_ZERO(mem, csz - SIZE_SZ);
+ VALGRIND_MAKE_MEM_DEFINED(mem, sz);
return mem;
}
}
diff --git a/common/malloc_simple.c b/common/malloc_simple.c
index 67ee623850..0a004d40e1 100644
--- a/common/malloc_simple.c
+++ b/common/malloc_simple.c
@@ -13,6 +13,7 @@
#include <mapmem.h>
#include <asm/global_data.h>
#include <asm/io.h>
+#include <valgrind/valgrind.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -45,6 +46,7 @@ void *malloc_simple(size_t bytes)
return ptr;
log_debug("%lx\n", (ulong)ptr);
+ VALGRIND_MALLOCLIKE_BLOCK(ptr, bytes, 0, false);
return ptr;
}
@@ -57,6 +59,7 @@ void *memalign_simple(size_t align, size_t bytes)
if (!ptr)
return ptr;
log_debug("aligned to %lx\n", (ulong)ptr);
+ VALGRIND_MALLOCLIKE_BLOCK(ptr, bytes, 0, false);
return ptr;
}
@@ -74,6 +77,13 @@ void *calloc(size_t nmemb, size_t elem_size)
return ptr;
}
+
+#if IS_ENABLED(CONFIG_VALGRIND)
+void free_simple(void *ptr)
+{
+ VALGRIND_FREELIKE_BLOCK(ptr, 0);
+}
+#endif
#endif
void malloc_simple_info(void)
diff --git a/include/malloc.h b/include/malloc.h
index 1fbaf3755c..e8c8b254c0 100644
--- a/include/malloc.h
+++ b/include/malloc.h
@@ -887,7 +887,11 @@ void malloc_simple_info(void);
#define malloc malloc_simple
#define realloc realloc_simple
#define memalign memalign_simple
+#if IS_ENABLED(CONFIG_VALGRIND)
+#define free free_simple
+#else
static inline void free(void *ptr) {}
+#endif
void *calloc(size_t nmemb, size_t size);
void *realloc_simple(void *ptr, size_t size);
#else
diff --git a/scripts/u-boot.supp b/scripts/u-boot.supp
new file mode 100644
index 0000000000..9562b27a61
--- /dev/null
+++ b/scripts/u-boot.supp
@@ -0,0 +1,53 @@
+{
+ dlmalloc
+ Memcheck:Addr1
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Addr4
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Addr8
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Addr1
+ fun:*
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Addr4
+ fun:*
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Addr8
+ fun:*
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Value4
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Value8
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Cond
+ src:dlmalloc.c
+}
+{
+ dlmalloc
+ Memcheck:Free
+ src:dlmalloc.c
+}
--
2.35.1
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