From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
To: ast@kernel.org
Cc: ravi.bangoria@linux.ibm.com, davem@davemloft.net,
yoshfuji@linux-ipv6.org, dsahern@kernel.org,
daniel@iogearbox.net, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, x86@kernel.org, hpa@zytor.com, andrii@kernel.org,
kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
john.fastabend@gmail.com, kpsingh@kernel.org,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org, naveen.n.rao@linux.vnet.ibm.com
Subject: [PATCH] x86 bpf: Fix extable offset calculation
Date: Tue, 22 Jun 2021 16:30:26 +0530 [thread overview]
Message-ID: <20210622110026.1157847-1-ravi.bangoria@linux.ibm.com> (raw)
In-Reply-To: <CAADnVQJux+8n-vpuK9FqTLuj4cXrp04pGkpvKaUdAPXLQ4c-PQ@mail.gmail.com>
commit 4c5de127598e1 ("bpf: Emit explicit NULL pointer checks
for PROBE_LDX instructions.") is emitting couple of instructions
before actual load. Consider those additional instructions while
calculating extable offset.
Fixes: 4c5de127598e1 ("bpf: Emit explicit NULL pointer checks for PROBE_LDX instructions.")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
arch/x86/net/bpf_jit_comp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 2a2e290fa5d8..231a8178cc11 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1297,7 +1297,7 @@ st: if (is_imm8(insn->off))
emit_ldx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off);
if (BPF_MODE(insn->code) == BPF_PROBE_MEM) {
struct exception_table_entry *ex;
- u8 *_insn = image + proglen;
+ u8 *_insn = image + proglen + (u8)(start_of_ldx - temp);
s64 delta;
/* populate jmp_offset for JMP above */
--
2.30.2
next parent reply other threads:[~2021-06-22 11:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAADnVQJux+8n-vpuK9FqTLuj4cXrp04pGkpvKaUdAPXLQ4c-PQ@mail.gmail.com>
2021-06-22 11:00 ` Ravi Bangoria [this message]
2021-06-25 4:01 ` [PATCH] x86 bpf: Fix extable offset calculation Alexei Starovoitov
2021-06-25 6:22 ` Ravi Bangoria
2021-06-25 15:07 ` Alexei Starovoitov
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