diff options
| author | Liao Chang <liaochang1@huawei.com> | 2023-01-16 14:43:42 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-01-24 21:38:19 -0800 |
| commit | ca0254998be4d74cf6add70ccfab0d2dbd362a10 (patch) | |
| tree | 489d403241a15312416673ec6148752e70e53aca | |
| parent | 5b89c6f9b2df2b7cf6da8e0b2b87c8995b378cad (diff) | |
| download | linux-ca0254998be4d74cf6add70ccfab0d2dbd362a10.tar.bz2 | |
riscv/kprobe: Fix instruction simulation of JALR
Set kprobe at 'jalr 1140(ra)' of vfs_write results in the following
crash:
[ 32.092235] Unable to handle kernel access to user memory without uaccess routines at virtual address 00aaaaaad77b1170
[ 32.093115] Oops [#1]
[ 32.093251] Modules linked in:
[ 32.093626] CPU: 0 PID: 135 Comm: ftracetest Not tainted 6.2.0-rc2-00013-gb0aa5e5df0cb-dirty #16
[ 32.093985] Hardware name: riscv-virtio,qemu (DT)
[ 32.094280] epc : ksys_read+0x88/0xd6
[ 32.094855] ra : ksys_read+0xc0/0xd6
[ 32.095016] epc : ffffffff801cda80 ra : ffffffff801cdab8 sp : ff20000000d7bdc0
[ 32.095227] gp : ffffffff80f14000 tp : ff60000080f9cb40 t0 : ffffffff80f13e80
[ 32.095500] t1 : ffffffff8000c29c t2 : ffffffff800dbc54 s0 : ff20000000d7be60
[ 32.095716] s1 : 0000000000000000 a0 : ffffffff805a64ae a1 : ffffffff80a83708
[ 32.095921] a2 : ffffffff80f160a0 a3 : 0000000000000000 a4 : f229b0afdb165300
[ 32.096171] a5 : f229b0afdb165300 a6 : ffffffff80eeebd0 a7 : 00000000000003ff
[ 32.096411] s2 : ff6000007ff76800 s3 : fffffffffffffff7 s4 : 00aaaaaad77b1170
[ 32.096638] s5 : ffffffff80f160a0 s6 : ff6000007ff76800 s7 : 0000000000000030
[ 32.096865] s8 : 00ffffffc3d97be0 s9 : 0000000000000007 s10: 00aaaaaad77c9410
[ 32.097092] s11: 0000000000000000 t3 : ffffffff80f13e48 t4 : ffffffff8000c29c
[ 32.097317] t5 : ffffffff8000c29c t6 : ffffffff800dbc54
[ 32.097505] status: 0000000200000120 badaddr: 00aaaaaad77b1170 cause: 000000000000000d
[ 32.098011] [<ffffffff801cdb72>] ksys_write+0x6c/0xd6
[ 32.098222] [<ffffffff801cdc06>] sys_write+0x2a/0x38
[ 32.098405] [<ffffffff80003c76>] ret_from_syscall+0x0/0x2
Since the rs1 and rd might be the same one, such as 'jalr 1140(ra)',
hence it requires obtaining the target address from rs1 followed by
updating rd.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230116064342.2092136-1-liaochang1@huawei.com
[Palmer: Pick Guo's cleanup]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/kernel/probes/simulate-insn.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c index d73e96f6ed7c..a20568bd1f1a 100644 --- a/arch/riscv/kernel/probes/simulate-insn.c +++ b/arch/riscv/kernel/probes/simulate-insn.c @@ -71,11 +71,11 @@ bool __kprobes simulate_jalr(u32 opcode, unsigned long addr, struct pt_regs *reg u32 rd_index = (opcode >> 7) & 0x1f; u32 rs1_index = (opcode >> 15) & 0x1f; - ret = rv_insn_reg_set_val(regs, rd_index, addr + 4); + ret = rv_insn_reg_get_val(regs, rs1_index, &base_addr); if (!ret) return ret; - ret = rv_insn_reg_get_val(regs, rs1_index, &base_addr); + ret = rv_insn_reg_set_val(regs, rd_index, addr + 4); if (!ret) return ret; |