Commit b3e0423c authored by Vasily Gorbik's avatar Vasily Gorbik

s390/kaslr: randomize amode31 base address

When the KASLR is enabled, randomize the base address of the amode31 image
within the first 2 GB, similar to the approach taken for the vmlinux
image. This makes it harder to predict the location of amode31 data
and code.
Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 6e259bc5
...@@ -278,7 +278,7 @@ void startup_kernel(void) ...@@ -278,7 +278,7 @@ void startup_kernel(void)
{ {
unsigned long max_physmem_end; unsigned long max_physmem_end;
unsigned long vmlinux_lma = 0; unsigned long vmlinux_lma = 0;
unsigned long amode31_lma; unsigned long amode31_lma = 0;
unsigned long asce_limit; unsigned long asce_limit;
unsigned long safe_addr; unsigned long safe_addr;
void *img; void *img;
...@@ -338,7 +338,9 @@ void startup_kernel(void) ...@@ -338,7 +338,9 @@ void startup_kernel(void)
/* vmlinux decompression is done, shrink reserved low memory */ /* vmlinux decompression is done, shrink reserved low memory */
physmem_reserve(RR_DECOMPRESSOR, 0, (unsigned long)_decompressor_end); physmem_reserve(RR_DECOMPRESSOR, 0, (unsigned long)_decompressor_end);
amode31_lma = vmlinux.default_lma - vmlinux.amode31_size; if (kaslr_enabled())
amode31_lma = randomize_within_range(vmlinux.amode31_size, PAGE_SIZE, 0, SZ_2G);
amode31_lma = amode31_lma ?: vmlinux.default_lma - vmlinux.amode31_size;
physmem_reserve(RR_AMODE31, amode31_lma, vmlinux.amode31_size); physmem_reserve(RR_AMODE31, amode31_lma, vmlinux.amode31_size);
/* /*
......
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