diff options
| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-09-04 01:33:23 -0700 |
|---|---|---|
| committer | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-04 12:58:04 +0200 |
| commit | 836b2fe544a5e9b5ce116622cb36fba33838c6fd (patch) | |
| tree | 95e38e4aaa0a6a78e373148b3d0af4aa2ab3d371 /arch/arc/lib/strlen.S | |
| download | linux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.tar.gz linux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.zip | |
selftests/bpf: Check that JMP32 pointer vs zero jumps are not predictedgrafted
Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which
the verifier used to skip, contains an out of bounds map value access,
hence w/o the previous patch the program is accepted. See previous patch
for detailed description.
Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Diffstat (limited to 'arch/arc/lib/strlen.S')
| -rw-r--r-- | arch/arc/lib/strlen.S | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/arc/lib/strlen.S b/arch/arc/lib/strlen.S new file mode 100644 index 000000000..dae428ceb --- /dev/null +++ b/arch/arc/lib/strlen.S @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + */ + +#include <linux/linkage.h> + +ENTRY_CFI(strlen) + or r3,r0,7 + ld r2,[r3,-7] + ld.a r6,[r3,-3] + mov r4,0x01010101 + ; uses long immediate +#ifdef __LITTLE_ENDIAN__ + asl_s r1,r0,3 + btst_s r0,2 + asl r7,r4,r1 + ror r5,r4 + sub r1,r2,r7 + bic_s r1,r1,r2 + mov.eq r7,r4 + sub r12,r6,r7 + bic r12,r12,r6 + or.eq r12,r12,r1 + and r12,r12,r5 + brne r12,0,.Learly_end +#else /* BIG ENDIAN */ + ror r5,r4 + btst_s r0,2 + mov_s r1,31 + sub3 r7,r1,r0 + sub r1,r2,r4 + bic_s r1,r1,r2 + bmsk r1,r1,r7 + sub r12,r6,r4 + bic r12,r12,r6 + bmsk.ne r12,r12,r7 + or.eq r12,r12,r1 + and r12,r12,r5 + brne r12,0,.Learly_end +#endif /* ENDIAN */ + +.Loop: + ld_s r2,[r3,4] + ld.a r6,[r3,8] + ; stall for load result + sub r1,r2,r4 + bic_s r1,r1,r2 + sub r12,r6,r4 + bic r12,r12,r6 + or r12,r12,r1 + and r12,r12,r5 + breq r12,0,.Loop +.Lend: + and.f r1,r1,r5 + sub.ne r3,r3,4 + mov.eq r1,r12 +#ifdef __LITTLE_ENDIAN__ + sub_s r2,r1,1 + bic_s r2,r2,r1 + norm r1,r2 + sub_s r0,r0,3 + lsr_s r1,r1,3 + sub r0,r3,r0 + j_s.d [blink] + sub r0,r0,r1 +#else /* BIG ENDIAN */ + lsr_s r1,r1,7 + mov.eq r2,r6 + bic_s r1,r1,r2 + norm r1,r1 + sub r0,r3,r0 + lsr_s r1,r1,3 + j_s.d [blink] + add r0,r0,r1 +#endif /* ENDIAN */ +.Learly_end: + b.d .Lend + sub_s.ne r1,r1,r1 +END_CFI(strlen) |