summaryrefslogtreecommitdiffstats
path: root/arch/alpha/lib/fls.c
diff options
context:
space:
mode:
authorEduard Zingerman <eddyz87@gmail.com>2026-09-04 01:33:23 -0700
committerKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 12:58:04 +0200
commit836b2fe544a5e9b5ce116622cb36fba33838c6fd (patch)
tree95e38e4aaa0a6a78e373148b3d0af4aa2ab3d371 /arch/alpha/lib/fls.c
downloadlinux-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/alpha/lib/fls.c')
-rw-r--r--arch/alpha/lib/fls.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/alpha/lib/fls.c b/arch/alpha/lib/fls.c
new file mode 100644
index 000000000..02e156776
--- /dev/null
+++ b/arch/alpha/lib/fls.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/alpha/lib/fls.c
+ */
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+/* This is fls(x)-1, except zero is held to zero. This allows most
+ efficient input into extbl, plus it allows easy handling of fls(0)=0. */
+
+const unsigned char __flsm1_tab[256] =
+{
+ 0,
+ 0,
+ 1, 1,
+ 2, 2, 2, 2,
+ 3, 3, 3, 3, 3, 3, 3, 3,
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+
+ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+};
+
+EXPORT_SYMBOL(__flsm1_tab);