From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted 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 Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- arch/powerpc/lib/string.S | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 arch/powerpc/lib/string.S (limited to 'arch/powerpc/lib/string.S') diff --git a/arch/powerpc/lib/string.S b/arch/powerpc/lib/string.S new file mode 100644 index 000000000..c3f5e7d31 --- /dev/null +++ b/arch/powerpc/lib/string.S @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * String handling functions for PowerPC. + * + * Copyright (C) 1996 Paul Mackerras. + */ +#include +#include +#include + + .text + +_GLOBAL(strncmp) + PPC_LCMPI 0,r5,0 + beq- 2f + mtctr r5 + addi r5,r3,-1 + addi r4,r4,-1 + .balign IFETCH_ALIGN_BYTES +1: lbzu r3,1(r5) + cmpwi 1,r3,0 + lbzu r0,1(r4) + subf. r3,r0,r3 + beqlr 1 + bdnzt eq,1b + blr +2: li r3,0 + blr +EXPORT_SYMBOL(strncmp) + +_GLOBAL(memchr) + PPC_LCMPI 0,r5,0 + beq- 2f + mtctr r5 + addi r3,r3,-1 + .balign IFETCH_ALIGN_BYTES +1: lbzu r0,1(r3) + cmpw 0,r0,r4 + bdnzf 2,1b + beqlr +2: li r3,0 + blr +EXPORT_SYMBOL(memchr) -- cgit v1.3.1