[PATCH 3/6] MIPS: net: BPF: Fix stack pointer allocation
From: Markos Chandras <hidden>
Date: 2015-06-04 10:56:58
Also in:
linux-mips, lkml
Subsystem:
bpf jit for mips (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), mips, the rest · Maintainers:
Johan Almbladh, Paul Burton, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Thomas Bogendoerfer, Linus Torvalds
Fix stack pointer offset which could potentially corrupt argument registers in the previous frame. The calculated offset reflects the size of all the registers we need to preserve so there is no need for this erroneous subtraction. Cc: netdev@vger.kernel.org Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <redacted> Cc: Daniel Borkmann <redacted> Cc: Hannes Frederic Sowa <redacted> Cc: linux-kernel@vger.kernel.org Signed-off-by: Markos Chandras <redacted> --- arch/mips/net/bpf_jit.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 56e0e8e9674d..84cd09ba230a 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c@@ -676,11 +676,7 @@ static unsigned int get_stack_depth(struct jit_ctx *ctx) sp_off += config_enabled(CONFIG_64BIT) ? (ARGS_USED_BY_JIT + 1) * SZREG : SZREG; - /* - * Subtract the bytes for the last registers since we only care about - * the location on the stack pointer. - */ - return sp_off - SZREG; + return sp_off; } static void build_prologue(struct jit_ctx *ctx)
--
2.4.2