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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2022-01-06 12:45:12 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-01-15 02:21:25 +0100 |
| commit | 3f5f766d5f7f95a69a630da3544a1a0cee1cdddf (patch) | |
| tree | 8a7dc3a6de0810d2cc7a72c889b75bc650c8d9a1 /arch/powerpc/include/asm/ppc-opcode.h | |
| parent | tools/bpf: Rename 'struct event' to avoid naming conflict (diff) | |
| download | linux-3f5f766d5f7f95a69a630da3544a1a0cee1cdddf.tar.xz linux-3f5f766d5f7f95a69a630da3544a1a0cee1cdddf.zip | |
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: 156d0e290e969c ("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
Diffstat (limited to 'arch/powerpc/include/asm/ppc-opcode.h')
| -rw-r--r-- | arch/powerpc/include/asm/ppc-opcode.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h index efad07081cc0..9675303b724e 100644 --- a/arch/powerpc/include/asm/ppc-opcode.h +++ b/arch/powerpc/include/asm/ppc-opcode.h @@ -500,6 +500,7 @@ #define PPC_RAW_LDX(r, base, b) (0x7c00002a | ___PPC_RT(r) | ___PPC_RA(base) | ___PPC_RB(b)) #define PPC_RAW_LHZ(r, base, i) (0xa0000000 | ___PPC_RT(r) | ___PPC_RA(base) | IMM_L(i)) #define PPC_RAW_LHBRX(r, base, b) (0x7c00062c | ___PPC_RT(r) | ___PPC_RA(base) | ___PPC_RB(b)) +#define PPC_RAW_LWBRX(r, base, b) (0x7c00042c | ___PPC_RT(r) | ___PPC_RA(base) | ___PPC_RB(b)) #define PPC_RAW_LDBRX(r, base, b) (0x7c000428 | ___PPC_RT(r) | ___PPC_RA(base) | ___PPC_RB(b)) #define PPC_RAW_STWCX(s, a, b) (0x7c00012d | ___PPC_RS(s) | ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_RAW_CMPWI(a, i) (0x2c000000 | ___PPC_RA(a) | IMM_L(i)) |