linux-stable/arch/powerpc
Naveen N. Rao 3f5f766d5f powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06
Johan reported the below crash with test_bpf on ppc64 e5500:

  test_bpf: #296 ALU_END_FROM_LE 64: 0x0123456789abcdef -> 0x67452301 jited:1
  Oops: Exception in kernel mode, sig: 4 [#1]
  BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500
  Modules linked in: test_bpf(+)
  CPU: 0 PID: 76 Comm: insmod Not tainted 5.14.0-03771-g98c2059e008a-dirty #1
  NIP:  8000000000061c3c LR: 80000000006dea64 CTR: 8000000000061c18
  REGS: c0000000032d3420 TRAP: 0700   Not tainted (5.14.0-03771-g98c2059e008a-dirty)
  MSR:  0000000080089000 <EE,ME>  CR: 88002822  XER: 20000000 IRQMASK: 0
  <...>
  NIP [8000000000061c3c] 0x8000000000061c3c
  LR [80000000006dea64] .__run_one+0x104/0x17c [test_bpf]
  Call Trace:
   .__run_one+0x60/0x17c [test_bpf] (unreliable)
   .test_bpf_init+0x6a8/0xdc8 [test_bpf]
   .do_one_initcall+0x6c/0x28c
   .do_init_module+0x68/0x28c
   .load_module+0x2460/0x2abc
   .__do_sys_init_module+0x120/0x18c
   .system_call_exception+0x110/0x1b8
   system_call_common+0xf0/0x210
  --- interrupt: c00 at 0x101d0acc
  <...>
  ---[ end trace 47b2bf19090bb3d0 ]---

  Illegal instruction

The illegal instruction turned out to be 'ldbrx' emitted for
BPF_FROM_[L|B]E, which was only introduced in ISA v2.06. Guard use of
the same and implement an alternative approach for older processors.

Fixes: 156d0e290e ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d1e51c6fdf572062cf3009a751c3406bda01b832.1641468127.git.naveen.n.rao@linux.vnet.ibm.com
2022-01-15 12:21:25 +11:00
..
boot powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
configs powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
crypto powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
include powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 2022-01-15 12:21:25 +11:00
kernel powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
kexec powerpc/kernel: Add __init attribute to eligible functions 2021-12-23 22:33:10 +11:00
kvm Merge branch 'topic/ppc-kvm' into next 2021-12-15 11:29:53 +11:00
lib powerpc/32: Fix boot failure with GCC latent entropy plugin 2021-12-23 22:36:58 +11:00
math-emu powerpc/64s: avoid reloading (H)SRR registers if they are still valid 2021-06-25 00:06:55 +10:00
mm powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
net powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 2022-01-15 12:21:25 +11:00
perf powerpc/perf: Fix spelling of "its" 2021-12-23 22:36:58 +11:00
platforms powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
purgatory
sysdev powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
tools powerpc/head_check: Fix shellcheck errors 2021-08-17 22:52:02 +10:00
xmon powerpc/xmon: Dump XIVE information for online-only processors. 2022-01-06 21:47:00 +11:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU 2021-12-09 22:41:13 +11:00
Kconfig.debug powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP 2021-08-25 13:35:48 +10:00
Makefile powerpc: check for support for -Wa,-m{power4,any} 2021-12-23 22:35:12 +11:00
Makefile.postlink