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authorRussell King <rmk+kernel@armlinux.org.uk>2018-01-13 16:10:07 +0000
committerRussell King <rmk+kernel@armlinux.org.uk>2018-01-17 19:36:43 +0000
commitd1220efd23484c72c82d5471f05daeb35b5d1916 (patch)
treead26dd35eea603c5bc13512692179a67ebc57aab
parentf4483f2cc1fdc03488c8a1452e545545ae5bda93 (diff)
ARM: net: bpf: fix stack alignment
As per 2dede2d8e925 ("ARM EABI: stack pointer must be 64-bit aligned after a CPU exception") the stack should be aligned to a 64-bit boundary on EABI systems. Ensure that the eBPF JIT appropraitely aligns the stack. Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
-rw-r--r--arch/arm/net/bpf_jit_32.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index ce36d2cab50c..d00a0eb0386e 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -179,8 +179,13 @@ static void jit_fill_hole(void *area, unsigned int size)
*ptr++ = __opcode_to_mem_arm(ARM_INST_UDF);
}
-/* Stack must be multiples of 16 Bytes */
-#define STACK_ALIGN(sz) (((sz) + 3) & ~3)
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
+/* EABI requires the stack to be aligned to 64-bit boundaries */
+#define STACK_ALIGNMENT 8
+#else
+/* Stack must be aligned to 32-bit boundaries */
+#define STACK_ALIGNMENT 4
+#endif
/* Stack space for BPF_REG_2, BPF_REG_3, BPF_REG_4,
* BPF_REG_5, BPF_REG_7, BPF_REG_8, BPF_REG_9,
@@ -194,7 +199,7 @@ static void jit_fill_hole(void *area, unsigned int size)
+ SCRATCH_SIZE + \
+ 4 /* extra for skb_copy_bits buffer */)
-#define STACK_SIZE STACK_ALIGN(_STACK_SIZE)
+#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT)
/* Get the offset of eBPF REGISTERs stored on scratch space. */
#define STACK_VAR(off) (STACK_SIZE-off-4)