linux/arch/riscv/kernel
Sami Tolvanen af0ead42f6
riscv: Add CFI error handling
With CONFIG_CFI_CLANG, the compiler injects a type preamble immediately
before each function and a check to validate the target function type
before indirect calls:

  ; type preamble
    .word <id>
  function:
    ...
  ; indirect call check
    lw      t1, -4(a0)
    lui     t2, <hi20>
    addiw   t2, t2, <lo12>
    beq     t1, t2, .Ltmp0
    ebreak
  .Ltmp0:
    jarl    a0

Implement error handling code for the ebreak traps emitted for the
checks. This produces the following oops on a CFI failure (generated
using lkdtm):

[   21.177245] CFI failure at lkdtm_indirect_call+0x22/0x32 [lkdtm]
(target: lkdtm_increment_int+0x0/0x18 [lkdtm]; expected type: 0x3ad55aca)
[   21.178483] Kernel BUG [#1]
[   21.178671] Modules linked in: lkdtm
[   21.179037] CPU: 1 PID: 104 Comm: sh Not tainted
6.3.0-rc6-00037-g37d5ec6297ab #1
[   21.179511] Hardware name: riscv-virtio,qemu (DT)
[   21.179818] epc : lkdtm_indirect_call+0x22/0x32 [lkdtm]
[   21.180106]  ra : lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm]
[   21.180426] epc : ffffffff01387092 ra : ffffffff01386f14 sp : ff20000000453cf0
[   21.180792]  gp : ffffffff81308c38 tp : ff6000000243f080 t0 : ff20000000453b78
[   21.181157]  t1 : 000000003ad55aca t2 : 000000007e0c52a5 s0 : ff20000000453d00
[   21.181506]  s1 : 0000000000000001 a0 : ffffffff0138d170 a1 : ffffffff013870bc
[   21.181819]  a2 : b5fea48dd89aa700 a3 : 0000000000000001 a4 : 0000000000000fff
[   21.182169]  a5 : 0000000000000004 a6 : 00000000000000b7 a7 : 0000000000000000
[   21.182591]  s2 : ff20000000453e78 s3 : ffffffffffffffea s4 : 0000000000000012
[   21.183001]  s5 : ff600000023c7000 s6 : 0000000000000006 s7 : ffffffff013882a0
[   21.183653]  s8 : 0000000000000008 s9 : 0000000000000002 s10: ffffffff0138d878
[   21.184245]  s11: ffffffff0138d878 t3 : 0000000000000003 t4 : 0000000000000000
[   21.184591]  t5 : ffffffff8133df08 t6 : ffffffff8133df07
[   21.184858] status: 0000000000000120 badaddr: 0000000000000000
cause: 0000000000000003
[   21.185415] [<ffffffff01387092>] lkdtm_indirect_call+0x22/0x32 [lkdtm]
[   21.185772] [<ffffffff01386f14>] lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm]
[   21.186093] [<ffffffff01383552>] lkdtm_do_action+0x22/0x34 [lkdtm]
[   21.186445] [<ffffffff0138350c>] direct_entry+0x128/0x13a [lkdtm]
[   21.186817] [<ffffffff8033ed8c>] full_proxy_write+0x58/0xb2
[   21.187352] [<ffffffff801d4fe8>] vfs_write+0x14c/0x33a
[   21.187644] [<ffffffff801d5328>] ksys_write+0x64/0xd4
[   21.187832] [<ffffffff801d53a6>] sys_write+0xe/0x1a
[   21.188171] [<ffffffff80003996>] ret_from_syscall+0x0/0x2
[   21.188595] Code: 0513 0f65 a303 ffc5 53b7 7e0c 839b 2a53 0363 0073 (9002) 9582
[   21.189178] ---[ end trace 0000000000000000 ]---
[   21.189590] Kernel panic - not syncing: Fatal exception

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com> # ISA bits
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230710183544.999540-12-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-23 14:16:39 -07:00
..
compat_vdso RISC-V Patches for the 6.4 Merge Window, Part 1 2023-04-28 16:55:39 -07:00
pi riscv: Fix orphan section warnings caused by kernel/pi 2023-05-09 18:20:23 -07:00
probes RISC-V Patches for the 6.5 Merge Window, Part 1 2023-06-30 09:37:26 -07:00
vdso riscv: replace deprecated scall with ecall 2023-06-20 09:02:09 -07:00
.gitignore
acpi.c RISC-V: ACPI : Fix for usage of pointers in different address space 2023-06-19 09:27:58 -07:00
alternative.c RISC-V: hwprobe: Remove __init on probe_vendor_features() 2023-04-25 21:58:42 -07:00
asm-offsets.c RISC-V: Add arch functions to support hibernation/suspend-to-disk 2023-04-29 11:25:13 -07:00
cacheinfo.c RISC-V Patches for the 6.4 Merge Window, Part 1 2023-04-28 16:55:39 -07:00
cfi.c riscv: Add CFI error handling 2023-08-23 14:16:39 -07:00
compat_signal.c
compat_syscall_table.c riscv: Implement syscall wrappers 2023-08-23 14:16:36 -07:00
cpu-hotplug.c riscv: Switch to hotplug core state synchronization 2023-05-15 13:44:59 +02:00
cpu.c Merge patch series "ISA string parser cleanups" 2023-06-23 10:06:20 -07:00
cpu_ops.c RISC-V: Align SBI probe implementation with spec 2023-04-29 13:04:50 -07:00
cpu_ops_sbi.c
cpu_ops_spinwait.c RISC-V: cpu_ops_spinwait.c should include head.h 2022-08-11 13:24:16 -07:00
cpufeature.c Merge patch series "ISA string parser cleanups" 2023-06-23 10:06:20 -07:00
crash_core.c RISC-V: Add arch_crash_save_vmcoreinfo support 2022-12-02 16:48:22 -08:00
crash_dump.c
crash_save_regs.S RISC-V: Fixup get incorrect user mode PC for kernel mode regs 2022-08-11 08:54:40 -07:00
efi-header.S riscv: Prepare EFI header for relocatable kernels 2023-04-19 07:46:28 -07:00
efi.c efi: Discover BTI support in runtime services regions 2023-02-04 09:19:02 +01:00
elf_kexec.c RISC-V: kexec: Fix memory leak of elf header buffer 2022-12-05 10:59:58 -08:00
entry.S riscv: replace deprecated scall with ecall 2023-06-20 09:02:09 -07:00
fpu.S
ftrace.c RISC-V: Don't check text_mutex during stop_machine 2023-03-09 14:58:51 -08:00
head.h riscv: entry: Convert to generic entry 2023-03-23 08:47:00 -07:00
head.S riscv: prevent stack corruption by reserving task_pt_regs(p) early 2023-06-08 07:16:49 -07:00
hibernate-asm.S riscv: hibernation: Remove duplicate call of suspend_restore_csrs 2023-06-19 09:27:57 -07:00
hibernate.c riscv: hibernate: remove WARN_ON in save_processor_state 2023-06-23 10:06:22 -07:00
image-vars.h riscv: Fix EFI stub usage of KASAN instrumented strcmp function 2023-04-19 07:24:52 -07:00
irq.c riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK 2023-06-22 10:38:36 -07:00
jump_label.c
kexec_relocate.S
kgdb.c RISC-V: rename parse_asm.h to insn.h 2022-12-29 06:59:47 -08:00
machine_kexec.c riscv: kexec: Fixup crash_smp_send_stop without multi cores 2022-11-29 21:50:59 -08:00
machine_kexec_file.c
Makefile riscv: Add CFI error handling 2023-08-23 14:16:39 -07:00
mcount-dyn.S riscv: entry: Consolidate general regs saving/restoring 2023-03-23 08:47:03 -07:00
mcount.S riscv: Add ftrace_stub_graph 2023-08-23 14:16:38 -07:00
module-sections.c
module.c riscv: module: Add ADD16 and SUB16 rela types 2023-01-31 23:29:40 -08:00
patch.c RISC-V: Don't check text_mutex during stop_machine 2023-03-09 14:58:51 -08:00
perf_callchain.c
perf_regs.c
process.c riscv: Add prctl controls for userspace vector management 2023-06-08 07:16:53 -07:00
ptrace.c riscv: Add ptrace vector support 2023-06-08 07:16:45 -07:00
reset.c
riscv_ksyms.c RISC-V: add infrastructure to allow different str* implementations 2023-01-31 11:43:23 -08:00
sbi-ipi.c RISC-V: Allow marking IPIs as suitable for remote FENCEs 2023-04-08 11:26:24 +01:00
sbi.c RISC-V: Align SBI probe implementation with spec 2023-04-29 13:04:50 -07:00
setup.c Merge patch series "riscv: Add vector ISA support" 2023-06-08 07:17:09 -07:00
signal.c riscv: signal: validate altstack to reflect Vector 2023-06-08 07:16:48 -07:00
smp.c RISC-V: drop error print from riscv_hartid_to_cpuid() 2023-07-04 09:04:12 -07:00
smpboot.c risc-v: Fix order of IPI enablement vs RCU startup 2023-07-05 07:24:38 -07:00
soc.c
stacktrace.c riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode 2023-03-09 14:50:35 -08:00
suspend.c RISC-V: Change suspend_save_csrs and suspend_restore_csrs to public function 2023-04-29 11:25:10 -07:00
suspend_entry.S riscv: Add types to indirectly called assembly functions 2023-08-23 14:16:37 -07:00
sys_riscv.c riscv: Implement syscall wrappers 2023-08-23 14:16:36 -07:00
syscall_table.c riscv: Implement syscall wrappers 2023-08-23 14:16:36 -07:00
time.c RISC-V: time.c: Add ACPI support for time_init() 2023-06-01 08:45:13 -07:00
traps.c riscv: Add CFI error handling 2023-08-23 14:16:39 -07:00
traps_misaligned.c riscv: traps_misaligned: do not duplicate stringify 2022-08-11 08:56:53 -07:00
vdso.c riscv: vdso: include vdso/vsyscall.h for vdso_data 2023-07-04 07:54:41 -07:00
vector.c riscv: vector: clear V-reg in the first-use trap 2023-07-01 07:38:21 -07:00
vmlinux-xip.lds.S riscv: vmlinux-xip.lds.S: remove .alternative section 2023-06-25 16:24:03 -07:00
vmlinux.lds.S riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION 2023-06-25 16:24:05 -07:00