[S] Change in coreboot[main]: malloc/memalign: Return NULL if the request is too large

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/80226?usp=email )

(

2 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.
 )Change subject: malloc/memalign: Return NULL if the request is too large
......................................................................

malloc/memalign: Return NULL if the request is too large

It's what this function family is defined to do, we currently don't
usually run into the case (see: not too many die() instances going
around), it's more useful to try to recover, and the JPEG parser can run
into it if the work buffer size exceeds the remaining heap, whereas its
sole user (the bootsplash code) knows what to do when seeing a NULL.

Use xmalloc() if you want an allocation that either works or dies.

tl;dr: That code path isn't usually taken. Right now it crashes. With
this patch it _might_ survive. There is a use-case for doing it like
that now.

Change-Id: I262fbad7daae0ca3aab583fda00665a2592deaa8
Signed-off-by: Patrick Georgi 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80226
Tested-by: build bot (Jenkins) 
Reviewed-by: Martin L Roth 
Reviewed-by: Eric Lai 
---
M src/lib/malloc.c
M tests/lib/malloc-test.c
2 files changed, 8 insertions(+), 11 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Martin L Roth: Looks good to me, approved
  Eric Lai: Looks good to me, approved

diff --git a/src/lib/malloc.c b/src/lib/malloc.c
index 052a53e..3029806 100644
--- a/src/lib/malloc.c
+++ b/src/lib/malloc.c
@@ -44,7 +44,10 @@
    			p, free_mem_ptr);
    	printk(BIOS_ERR, "but free_mem_end_ptr is %p\n",
    			free_mem_end_ptr);
-		die("Error! %s: Out of memory (free_mem_ptr >= free_mem_end_ptr)", __func__);
+		printk(BIOS_ERR, "Error! %s: Out of memory "
+				"(free_mem_ptr >= free_mem_end_ptr)",
+				__func__);
+		return NULL;
    }

MALLOCDBG("%s %p\n", __func__, p);
diff --git a/tests/lib/malloc-test.c b/tests/lib/malloc-test.c
index 452d74f..f5d528e 100644
--- a/tests/lib/malloc-test.c
+++ b/tests/lib/malloc-test.c
@@ -34,11 +34,6 @@
 TEST_SYMBOL(_heap, _test_heap);
 TEST_SYMBOL(_eheap, _etest_heap);

-void die(const char *msg, ...)
-{
-	function_called();
-}
-
 static int setup_test(void **state)
 {
    free_mem_ptr = &_heap;
@@ -56,9 +51,8 @@

static void test_malloc_out_of_memory(void **state)
 {
-	/* Expect die() call if out of memory */
-	expect_function_call(die);
-	cb_malloc(TEST_HEAP_SZ);
+	void *ptr = cb_malloc(TEST_HEAP_SZ);
+	assert_ptr_equal(ptr, NULL);
 }

static void test_malloc_zero(void **state)
@@ -102,8 +96,8 @@

static void test_memalign_out_of_memory(void **state)
 {
-	expect_function_call(die);
-	cb_memalign(16, TEST_HEAP_SZ);
+	void *ptr = cb_memalign(16, TEST_HEAP_SZ);
+	assert_ptr_equal(ptr, NULL);
 }

static void test_memalign_zero(void **state)