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| author | Jisheng Zhang <jszhang@kernel.org> | 2024-06-24 07:53:16 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-07-26 05:50:47 -0700 |
| commit | b5db73fb18257cd5d9cb59bc4b779fffa629566a (patch) | |
| tree | 775ebd49b77381b1fc47d4e03e1bdbc7b2c40814 /arch/riscv/kernel | |
| parent | 1d20e5d437cfebefb5e6f4d652c3a1561fc23fc7 (diff) | |
| download | lwn-b5db73fb18257cd5d9cb59bc4b779fffa629566a.tar.gz lwn-b5db73fb18257cd5d9cb59bc4b779fffa629566a.zip | |
riscv: enable HAVE_ARCH_STACKLEAK
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.
At the same time, disables the plugin in EFI stub code because EFI stub
is out of scope for the protection.
Tested on qemu and milkv duo:
/ # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
[ 38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING
[ 38.678448] lkdtm: stackleak stack usage:
[ 38.678448] high offset: 288 bytes
[ 38.678448] current: 496 bytes
[ 38.678448] lowest: 1328 bytes
[ 38.678448] tracked: 1328 bytes
[ 38.678448] untracked: 448 bytes
[ 38.678448] poisoned: 14312 bytes
[ 38.678448] low offset: 8 bytes
[ 38.689887] lkdtm: OK: the rest of the thread stack is properly erased
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel')
| -rw-r--r-- | arch/riscv/kernel/entry.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index c933460ed3e9..ac2e908d4418 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -133,6 +133,10 @@ SYM_CODE_START_NOALIGN(ret_from_exception) #endif bnez s0, 1f +#ifdef CONFIG_GCC_PLUGIN_STACKLEAK + call stackleak_erase_on_task_stack +#endif + /* Save unwound kernel stack pointer in thread_info */ addi s0, sp, PT_SIZE_ON_STACK REG_S s0, TASK_TI_KERNEL_SP(tp) |