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authorSchichan Nicolas <nschichan@freebox.fr>2012-12-10 14:49:40 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-12-11 00:19:29 +0000
commitfe15f3f1067c56820da44aa92659f2f908fd3caa (patch)
tree908f939cbcbe48459d4b57fcae5c5f2a21082b56 /arch/arm/net
parent89c2e00978ada02a5b84b361faee954cbc7a0386 (diff)
ARM: 7598/1: net: bpf_jit_32: fix sp-relative load/stores offsets.
The offset must be multiplied by 4 to be sure to access the correct 32bit word in the stack scratch space. For instance, a store at scratch memory cell #1 was generating the following: st r4, [sp, #1] While the correct code for this is: st r4, [sp, #4] To reproduce the bug (assuming your system has a NIC with the mac address 52:54:00:12:34:56): echo 0 > /proc/sys/net/core/bpf_jit_enable tcpdump -ni eth0 "ether[1] + ether[2] - ether[3] * ether[4] - ether[5] \ == -0x3AA" # this will capture packets as expected echo 1 > /proc/sys/net/core/bpf_jit_enable tcpdump -ni eth0 "ether[1] + ether[2] - ether[3] * ether[4] - ether[5] \ == -0x3AA" # this will not. This bug was present since the original inclusion of bpf_jit for ARM (ddecdfce: ARM: 7259/3: net: JIT compiler for packet filters). Signed-off-by: Nicolas Schichan <nschichan@freebox.fr> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/net')
-rw-r--r--arch/arm/net/bpf_jit_32.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index a64d3496830..b6f305e3b90 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -42,7 +42,7 @@
#define r_skb_hl ARM_R8
#define SCRATCH_SP_OFFSET 0
-#define SCRATCH_OFF(k) (SCRATCH_SP_OFFSET + (k))
+#define SCRATCH_OFF(k) (SCRATCH_SP_OFFSET + 4 * (k))
#define SEEN_MEM ((1 << BPF_MEMWORDS) - 1)
#define SEEN_MEM_WORD(k) (1 << (k))