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powerpc: Remove __kernel_text_address() in show_instructions()

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[ Upstream commit d9ab6da64f ]

That test was introducted in 2006 by
commit 00ae36de49 ("[POWERPC] Better check in show_instructions").
At that time, there was no BPF progs.

As seen in message of commit 89d21e259a ("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@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4fd69ef7945518c3e27f96b95046a5c1468d35bf.1675245773.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Christophe Leroy
2023-02-01 11:04:23 +01:00
committed by Greg Kroah-Hartman
parent afde69b0a5
commit 16d96351ff
1 changed files with 1 additions and 2 deletions
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3
arch/powerpc/kernel/process.c
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@@ -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)