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authorWang YanQing <udknight@gmail.com>2018-07-26 00:46:11 +0800
committerDaniel Borkmann <daniel@iogearbox.net>2018-07-26 02:51:12 +0200
commit9e4e5b5c86661e767f3074bedbbf2ca59f8fbd18 (patch)
treeb34dac046b158573a00eda8d38f440c456d25e6b /arch/x86/net
parent684cce1c31d2c0c9383cbcca200b9cf3b1f1d21d (diff)
downloadlinux-9e4e5b5c86661e767f3074bedbbf2ca59f8fbd18.tar.gz
bpf, x32: Fix regression caused by commit 24dea04767e6
Commit 24dea04767e6 ("bpf, x32: remove ld_abs/ld_ind")
removed the 4 /* Extra space for skb_copy_bits buffer */
from _STACK_SIZE, but it didn't fix the concerned code
in emit_prologue and emit_epilogue, and this error will
bring very strange kernel runtime errors. This patch
fixes it.

Fixes: 24dea04767e6 ("bpf, x32: remove ld_abs/ld_ind")
Reported-by: Meelis Roos <mroos@linux.ee>
Bisected-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'arch/x86/net')
-rw-r--r--arch/x86/net/bpf_jit_comp32.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index 55799873ebe5..8f6cc71e0848 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -1441,8 +1441,8 @@ static void emit_prologue(u8 **pprog, u32 stack_depth)
 
 	/* sub esp,STACK_SIZE */
 	EMIT2_off32(0x81, 0xEC, STACK_SIZE);
-	/* sub ebp,SCRATCH_SIZE+4+12*/
-	EMIT3(0x83, add_1reg(0xE8, IA32_EBP), SCRATCH_SIZE + 16);
+	/* sub ebp,SCRATCH_SIZE+12*/
+	EMIT3(0x83, add_1reg(0xE8, IA32_EBP), SCRATCH_SIZE + 12);
 	/* xor ebx,ebx */
 	EMIT2(0x31, add_2reg(0xC0, IA32_EBX, IA32_EBX));
 
@@ -1475,8 +1475,8 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
 	/* mov edx,dword ptr [ebp+off]*/
 	EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX), STACK_VAR(r0[1]));
 
-	/* add ebp,SCRATCH_SIZE+4+12*/
-	EMIT3(0x83, add_1reg(0xC0, IA32_EBP), SCRATCH_SIZE + 16);
+	/* add ebp,SCRATCH_SIZE+12*/
+	EMIT3(0x83, add_1reg(0xC0, IA32_EBP), SCRATCH_SIZE + 12);
 
 	/* mov ebx,dword ptr [ebp-12]*/
 	EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX), -12);