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-rw-r--r--arch/arm/mm/init.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 2c2cce9cd8c8..fdc87f9bda55 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -416,6 +416,17 @@ static inline int free_area(unsigned long pfn, unsigned long end, char *s)
return pages;
}
+/*
+ * Poison init memory with an undefined instruction (ARM) or a branch to an
+ * undefined instruction (Thumb).
+ */
+static inline void poison_init_mem(void *s, size_t count)
+{
+ u32 *p = (u32 *)s;
+ while ((count = count - 4))
+ *p++ = 0xe7fddef0;
+}
+
static inline void
free_memmap(unsigned long start_pfn, unsigned long end_pfn)
{
@@ -696,11 +707,13 @@ void free_initmem(void)
#ifdef CONFIG_HAVE_TCM
extern char __tcm_start, __tcm_end;
+ poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
__phys_to_pfn(__pa(&__tcm_end)),
"TCM link");
#endif
+ poison_init_mem(__init_begin, __init_end - __init_begin);
if (!machine_is_integrator() && !machine_is_cintegrator())
totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
__phys_to_pfn(__pa(__init_end)),
@@ -713,10 +726,12 @@ static int keep_initrd;
void free_initrd_mem(unsigned long start, unsigned long end)
{
- if (!keep_initrd)
+ if (!keep_initrd) {
+ poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
totalram_pages += free_area(__phys_to_pfn(__pa(start)),
__phys_to_pfn(__pa(end)),
"initrd");
+ }
}
static int __init keepinitrd_setup(char *__unused)
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