| Message ID | 20230116064342.2092136-1-liaochang1@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ca0254998be4d74cf6add70ccfab0d2dbd362a10 |
| Delegated to: | Palmer Dabbelt |
| Headers | show |
| Series | riscv/kprobe: Fix instruction simulation of JALR | expand |
On Mon, Jan 16, 2023 at 2:46 PM Liao Chang <liaochang1@huawei.com> wrote: > > 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> > --- > arch/riscv/kernel/probes/simulate-insn.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c > index d73e96f6ed7c..02aa262fb2ac 100644 > --- a/arch/riscv/kernel/probes/simulate-insn.c > +++ b/arch/riscv/kernel/probes/simulate-insn.c > @@ -71,17 +71,13 @@ 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); > - if (!ret) > - return ret; > - > ret = rv_insn_reg_get_val(regs, rs1_index, &base_addr); > if (!ret) > return ret; Ah, thank you, If rd == rs1, the regs-><rs1> got a overwritten value, my mistake. We should read rs1 firstly. But for the patch, just exchanging the position is enough; keep the original sequence for coding convention. eg: @@ -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; Then: Reviewed-by: Guo Ren <guoren@kernel.org> > > instruction_pointer_set(regs, (base_addr + sign_extend32((imm), 11))&~1); > > - return ret; > + return rv_insn_reg_set_val(regs, rd_index, addr + 4); > } > > #define auipc_rd_idx(opcode) \ > -- > 2.25.1 >
On Mon, 16 Jan 2023 14:43:42 +0800, Liao Chang wrote: > 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 > > [...] Applied, thanks! (with Guo's suggested cleanup) [1/1] riscv/kprobe: Fix instruction simulation of JALR https://git.kernel.org/palmer/c/ca0254998be4 Best regards,
Hello: This patch was applied to riscv/linux.git (fixes) by Palmer Dabbelt <palmer@rivosinc.com>: On Mon, 16 Jan 2023 14:43:42 +0800 you wrote: > 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 > > [...] Here is the summary with links: - riscv/kprobe: Fix instruction simulation of JALR https://git.kernel.org/riscv/c/ca0254998be4 You are awesome, thank you!
diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c index d73e96f6ed7c..02aa262fb2ac 100644 --- a/arch/riscv/kernel/probes/simulate-insn.c +++ b/arch/riscv/kernel/probes/simulate-insn.c @@ -71,17 +71,13 @@ 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); - if (!ret) - return ret; - ret = rv_insn_reg_get_val(regs, rs1_index, &base_addr); if (!ret) return ret; instruction_pointer_set(regs, (base_addr + sign_extend32((imm), 11))&~1); - return ret; + return rv_insn_reg_set_val(regs, rd_index, addr + 4); } #define auipc_rd_idx(opcode) \
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> --- arch/riscv/kernel/probes/simulate-insn.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)