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authorKefeng Wang <wangkefeng.wang@huawei.com>2021-08-12 19:47:02 +0800
committerPalmer Dabbelt <palmerdabbelt@google.com>2021-09-10 22:25:34 -0700
commitd5935537c8256fc63c77d5f4914dfd6e3ef43241 (patch)
tree879e8965f6c8908490c48bd80d528a0cae81601e /arch
parentefe1e08bca9a1fab2b0ad886be4fb5335dcbf29c (diff)
riscv: Improve stack randomisation on RV64
This enlarges the bits availiable for stack randomisation on RV64 from the default of 8MiB to 1GiB, to match arm64 and x86. Also, update the documentation to reflect our support for stack randomisation. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> [Palmer: commit text] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/include/asm/elf.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index f4b490cd0e5d..f53c40026c7a 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -42,6 +42,9 @@
*/
#define ELF_ET_DYN_BASE ((TASK_SIZE / 3) * 2)
+#ifdef CONFIG_64BIT
+#define STACK_RND_MASK (0x3ffff >> (PAGE_SHIFT - 12))
+#endif
/*
* This yields a mask that user programs can use to figure out what
* instruction set this CPU supports. This could be done in user space,