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>
---
arch/powerpc/kernel/process.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index c22cc234672f..effe9697905d 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)
--
2.39.1
