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authorEduard Zingerman <eddyz87@gmail.com>2026-09-04 17:05:56 -0700
committerAlexei Starovoitov <ast@kernel.org>2026-09-04 18:17:30 -0700
commit506ada89629ec7059b96ecfb0dc7d33ece0103ca (patch)
tree0b07297409b68d2333fb4f0eae7f3b072eb68d4c /arch/powerpc/lib/string.S
downloadlinux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.tar.gz
linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.zip
bpf: mark a NULL kfunc argument precisegrafted
check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/powerpc/lib/string.S')
-rw-r--r--arch/powerpc/lib/string.S43
1 files changed, 43 insertions, 0 deletions
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 <linux/export.h>
+#include <asm/ppc_asm.h>
+#include <asm/cache.h>
+
+ .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)