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| author |   Guo Ren <guoren@linux.alibaba.com> | 2022-04-05 15:13:06 +0800 |
|---|---|---|
| committer |   Palmer Dabbelt <palmer@rivosinc.com> | 2022-04-26 13:36:31 -0700 |
| commit | dfb0bfa738f5c58b5c6e81262a0ee4ba154c3f28 (patch) | |
| tree | e9110b38f8891d3d31f0ac4c601caadb7a83f520 /arch/riscv/kernel/entry.S | |
| parent | riscv: compat: syscall: Add compat_sys_call_table implementation (diff) | |
| download | linux-dev-dfb0bfa738f5c58b5c6e81262a0ee4ba154c3f28.tar.xz linux-dev-dfb0bfa738f5c58b5c6e81262a0ee4ba154c3f28.zip | |
riscv: compat: syscall: Add entry.S implementation
Implement the entry of compat_sys_call_table[] in asm. Ref to
riscv-privileged spec 4.1.1 Supervisor Status Register (sstatus):
BIT[32:33] = UXL[1:0]:
- 1:32
- 2:64
- 3:128
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220405071314.3225832-13-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/entry.S')
| -rw-r--r-- | arch/riscv/kernel/entry.S | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index c8b9ce274b9a..2e5b88ca11ce 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -207,13 +207,27 @@ check_syscall_nr: * Syscall number held in a7. * If syscall number is above allowed value, redirect to ni_syscall. */ - bgeu a7, t0, 1f + bgeu a7, t0, 3f +#ifdef CONFIG_COMPAT + REG_L s0, PT_STATUS(sp) + srli s0, s0, SR_UXL_SHIFT + andi s0, s0, (SR_UXL >> SR_UXL_SHIFT) + li t0, (SR_UXL_32 >> SR_UXL_SHIFT) + sub t0, s0, t0 + bnez t0, 1f + + /* Call compat_syscall */ + la s0, compat_sys_call_table + j 2f +1: +#endif /* Call syscall */ la s0, sys_call_table +2: slli t0, a7, RISCV_LGPTR add s0, s0, t0 REG_L s0, 0(s0) -1: +3: jalr s0 ret_from_syscall: |