Patch "MIPS: BPF: Fix build on pre-R2 little endian CPUs" has been added to the 4.2-stable tree
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This is a note to let you know that I've just added the patch titled
MIPS: BPF: Fix build on pre-R2 little endian CPUs
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mips-bpf-fix-build-on-pre-r2-little-endian-cpus.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
b259e51f2e29390518021f9b8df55a3de42f371bMon Sep 17 00:00:00 2001
From: Aurelien Jarno <[email protected]>
Date: Sat, 5 Sep 2015 18:46:57 +0200
Subject: MIPS: BPF: Fix build on pre-R2 little endian CPUs
From: Aurelien Jarno <[email protected]>
commit b259e51f2e29390518021f9b8df55a3de42f371b upstream.
The rotr, seh and wsbh instructions have been introduced with the R2 ISA. Thus the current BPF code fails to build on pre-R2 little endian CPUs:
CC arch/mips/net/bpf_jit.o
AS arch/mips/net/bpf_jit_asm.o
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S: Assembler messages:
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:67: Error: opcode not supported on this processor: mips32 (mips32) wsbh $8,$19' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:68: Error: opcode not supported on this processor: mips32 (mips32) rotr $19,$8,16' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:83: Error: opcode not supported on this processor: mips32 (mips32) wsbh $8,$19' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:84: Error: opcode not supported on this processor: mips32 (mips32) seh $19,$8' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:151: Error: opcode not supported on this processor: mips32 (mips32) wsbh $8,$12' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:153: Error: opcode not supported on this processor: mips32 (mips32) rotr $19,$8,16' /home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:164: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $19,$12' /home/aurel32/linux-4.2/scripts/Makefile.build:294: recipe for target 'arch/mips/net/bpf_jit_asm.o' failed
Fix that by providing equivalent code for these CPUs.
Patchwork: https://patchwork.linux-mips.org/patch/11098/
--- arch/mips/net/bpf_jit_asm.S | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+)
arch/mips/net/bpf_jit_asm.S +42 -0
@@ -64,8 +64,20 @@ sk_load_word_positive: PTR_ADDU t1, $r_skb_data, offset lw $r_A, 0(t1) #ifdef CONFIG_CPU_LITTLE_ENDIAN +# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2) wsbh t0, $r_A rotr $r_A, t0, 16 +# else + sll t0, $r_A, 24 + srl t1, $r_A, 24 + srl t2, $r_A, 8 + or t0, t0, t1 + andi t2, t2, 0xff00 + andi t1, $r_A, 0xff00 + or t0, t0, t2 + sll t1, t1, 8 + or $r_A, t0, t1 +# endif #endif jr $r_ra move $r_ret, zero
@@ -80,8 +92,16 @@ sk_load_half_positive: PTR_ADDU t1, $r_skb_data, offset lh $r_A, 0(t1) #ifdef CONFIG_CPU_LITTLE_ENDIAN +# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2) wsbh t0, $r_A seh $r_A, t0 +# else + sll t0, $r_A, 24 + andi t1, $r_A, 0xff00 + sra t0, t0, 16 + srl t1, t1, 8 + or $r_A, t0, t1 +# endif #endif jr $r_ra move $r_ret, zero
@@ -148,9 +168,22 @@ sk_load_byte_positive: NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp) bpf_slow_path_common(4) #ifdef CONFIG_CPU_LITTLE_ENDIAN +# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2) wsbh t0, $r_s0 jr $r_ra rotr $r_A, t0, 16 +# else + sll t0, $r_s0, 24 + srl t1, $r_s0, 24 + srl t2, $r_s0, 8 + or t0, t0, t1 + andi t2, t2, 0xff00 + andi t1, $r_s0, 0xff00 + or t0, t0, t2 + sll t1, t1, 8 + jr $r_ra + or $r_A, t0, t1 +# endif #else jr $r_ra move $r_A, $r_s0
@@ -161,8 +194,17 @@ NESTED(bpf_slow_path_word, (6 * SZREG), NESTED(bpf_slow_path_half, (6 * SZREG), $r_sp) bpf_slow_path_common(2) #ifdef CONFIG_CPU_LITTLE_ENDIAN +# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2) jr $r_ra wsbh $r_A, $r_s0 +# else + sll t0, $r_s0, 8 + andi t1, $r_s0, 0xff00 + andi t0, t0, 0xff00 + srl t1, t1, 8 + jr $r_ra + or $r_A, t0, t1 +# endif #else jr $r_ra move $r_A, $r_s0
Patches currently in stable-queue which might be from [email protected] are
queue-4.2/mips-bpf-fix-build-on-pre-r2-little-endian-cpus.patch queue-4.2/mips-bpf-avoid-unreachable-code-on-little-endian.patch