This is a note to let you know that I've just added the patch titled
ARM: net: bpf: fix stack alignment
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: arm-net-bpf-fix-stack-alignment.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From d1220efd23484c72c82d5471f05daeb35b5d1916 Mon Sep 17 00:00:00 2001
From: Russell King rmk+kernel@armlinux.org.uk Date: Sat, 13 Jan 2018 16:10:07 +0000 Subject: ARM: net: bpf: fix stack alignment
From: Russell King rmk+kernel@armlinux.org.uk
commit d1220efd23484c72c82d5471f05daeb35b5d1916 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm/net/bpf_jit_32.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
--- 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, un *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, un + 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)
Patches currently in stable-queue which might be from rmk+kernel@armlinux.org.uk are
queue-4.14/arm-net-bpf-fix-stack-alignment.patch queue-4.14/arm-net-bpf-fix-ldx-instructions.patch queue-4.14/arm-net-bpf-fix-register-saving.patch queue-4.14/arm-net-bpf-move-stack-documentation.patch queue-4.14/arm-net-bpf-correct-stack-layout-documentation.patch queue-4.14/arm-net-bpf-clarify-tail_call-index.patch queue-4.14/arm-net-bpf-avoid-bx-instruction-on-non-thumb-capable-cpus.patch queue-4.14/arm-net-bpf-fix-tail-call-jumps.patch