This is a note to let you know that I've just added the patch titled
powerpc: Remove __kernel_text_address() in show_instructions()
to the 6.2-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:
powerpc-remove-__kernel_text_address-in-show_instruc.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6797d61acc050efef81cc51a95676f37ea2647f3
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date: Wed Feb 1 11:04:23 2023 +0100
powerpc: Remove __kernel_text_address() in show_instructions()
[ Upstream commit d9ab6da64fd15608c9feb20d769d8df1a32fe212 ]
That test was introducted in 2006 by
commit 00ae36de49cc ("[POWERPC] Better check in show_instructions").
At that time, there was no BPF progs.
As seen in message of commit 89d21e259a94 ("powerpc/bpf/32: Fix Oops
on tail call tests"), when a page fault occurs in test_bpf.ko for
instance, the code is dumped as XXXXXXXXs. Allthough
__kernel_text_address() checks is_bpf_text_address(), it seems it is
not enough.
Today, show_instructions() uses get_kernel_nofault() to read the code,
so there is no real need for additional verifications.
ARM64 and x86 don't do any additional check before dumping
instructions. Do the same and remove __kernel_text_address()
in show_instructions().
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/4fd69ef7945518c3e27f96b95046a5c1468d35bf.1675245773.git.christophe.leroy@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index c22cc234672f9..effe9697905dc 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1405,8 +1405,7 @@ static void show_instructions(struct pt_regs *regs)
for (i = 0; i < NR_INSN_TO_PRINT; i++) {
int instr;
- if (!__kernel_text_address(pc) ||
- get_kernel_nofault(instr, (const void *)pc)) {
+ if (get_kernel_nofault(instr, (const void *)pc)) {
pr_cont("XXXXXXXX ");
} else {
if (nip == pc)
