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| author | Jisheng Zhang <jszhang@kernel.org> | 2024-07-20 20:06:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-10-17 16:26:37 +0300 |
| commit | 979abe54c234e26dd0d19021a6c9edb7686ef128 (patch) | |
| tree | 697c3b9014c3a163d1fd8bd7aa6a9939e837c0d8 /arch | |
| parent | a356934005c9856738df9edf7b42cbbf5fd4a436 (diff) | |
| download | linux-979abe54c234e26dd0d19021a6c9edb7686ef128.tar.xz | |
riscv: avoid Imbalance in RAS
[ Upstream commit 8f1534e7440382d118c3d655d3a6014128b2086d ]
Inspired by[1], modify the code to remove the code of modifying ra to
avoid imbalance RAS (return address stack) which may lead to incorret
predictions on return.
Link: https://lore.kernel.org/linux-riscv/20240607061335.2197383-1-cyrilbur@tenstorrent.com/ [1]
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Cyril Bur <cyrilbur@tenstorrent.com>
Link: https://lore.kernel.org/r/20240720170659.1522-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/kernel/entry.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index ac2e908d4418..fefb8e7d957a 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -239,8 +239,8 @@ SYM_CODE_START(ret_from_fork) jalr s0 1: move a0, sp /* pt_regs */ - la ra, ret_from_exception - tail syscall_exit_to_user_mode + call syscall_exit_to_user_mode + j ret_from_exception SYM_CODE_END(ret_from_fork) #ifdef CONFIG_IRQ_STACKS |