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[v1,02/10] powerpc: Remove __kernel_text_address() in show_instructions()

Message ID 96a35025667d6e44f5253f82f61bb49b0a6ecf2a.1669881248.git.christophe.leroy@csgroup.eu (mailing list archive)
State Superseded
Headers show
Series [v1,01/10] powerpc/bpf/32: Fix Oops on tail call tests | expand

Commit Message

Christophe Leroy Dec. 1, 2022, 7:56 a.m. UTC 
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@csgroup.eu>
---
 arch/powerpc/kernel/process.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
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Patch

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index e3e1feaa536a..c4e9f090ad22 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1373,8 +1373,7 @@  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)