linux/arch
Amit Daniel Kachhap 93396936ed arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions
Currently the ARMv8.3-PAuth combined branch instructions (braa, retaa
etc.) are not simulated for out-of-line execution with a handler. Hence the
uprobe of such instructions leads to kernel warnings in a loop as they are
not explicitly checked and fall into INSN_GOOD categories. Other combined
instructions like LDRAA and LDRBB can be probed.

The issue of the combined branch instructions is fixed by adding
group definitions of all such instructions and rejecting their probes.
The instruction groups added are br_auth(braa, brab, braaz and brabz),
blr_auth(blraa, blrab, blraaz and blrabz), ret_auth(retaa and retab) and
eret_auth(eretaa and eretab).

Warning log:
 WARNING: CPU: 0 PID: 156 at arch/arm64/kernel/probes/uprobes.c:182 uprobe_single_step_handler+0x34/0x50
 Modules linked in:
 CPU: 0 PID: 156 Comm: func Not tainted 5.9.0-rc3 #188
 Hardware name: Foundation-v8A (DT)
 pstate: 804003c9 (Nzcv DAIF +PAN -UAO BTYPE=--)
 pc : uprobe_single_step_handler+0x34/0x50
 lr : single_step_handler+0x70/0xf8
 sp : ffff800012af3e30
 x29: ffff800012af3e30 x28: ffff000878723b00
 x27: 0000000000000000 x26: 0000000000000000
 x25: 0000000000000000 x24: 0000000000000000
 x23: 0000000060001000 x22: 00000000cb000022
 x21: ffff800012065ce8 x20: ffff800012af3ec0
 x19: ffff800012068d50 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000
 x15: 0000000000000000 x14: 0000000000000000
 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: 0000000000000000
 x9 : ffff800010085c90 x8 : 0000000000000000
 x7 : 0000000000000000 x6 : ffff80001205a9c8
 x5 : ffff80001205a000 x4 : ffff80001233db80
 x3 : ffff8000100a7a60 x2 : 0020000000000003
 x1 : 0000fffffffff008 x0 : ffff800012af3ec0
 Call trace:
  uprobe_single_step_handler+0x34/0x50
  single_step_handler+0x70/0xf8
  do_debug_exception+0xb8/0x130
  el0_sync_handler+0x138/0x1b8
  el0_sync+0x158/0x180

Fixes: 74afda4016 ("arm64: compile the kernel with ptrauth return address signing")
Fixes: 04ca3204fa ("arm64: enable pointer authentication")
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-2-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-14 12:07:02 +01:00
..
alpha treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
arc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
arm A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
arm64 arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions 2020-09-14 12:07:02 +01:00
c6x treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
csky treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
h8300 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
hexagon treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
ia64 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
m68k treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
microblaze treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mips A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
nds32 A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
nios2 mm/nios2: use general page fault accounting 2020-08-12 10:58:03 -07:00
openrisc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
parisc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
powerpc A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
riscv treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
s390 A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
sh treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sparc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
um treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
x86 Three interrupt related fixes for X86: 2020-08-30 12:01:23 -07:00
xtensa treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
.gitignore
Kconfig A set oftimekeeping/VDSO updates: 2020-08-14 14:26:08 -07:00