From: Peter Zijlstra <peterz@infradead.org>
To: bpf@vger.kernel.org
Subject: [PATCH bpf-next 14/17] x86/alternative: Add debug prints to apply_retpolines()
Date: Wed, 27 Oct 2021 10:52:57 +0200 [thread overview]
Message-ID: <20211027085520.992974471@infradead.org> (raw)
In-Reply-To: 20211027085243.008677168@infradead.org
Make sure we can see the text changes when booting with
'debug-alternative'.
Example output:
[ ] SMP alternatives: retpoline at: __traceiter_initcall_level+0x1f/0x30 (ffffffff8100066f) len: 5 to: __x86_indirect_thunk_rax+0x0/0x20
[ ] SMP alternatives: ffffffff82603e58: [2:5) optimized NOPs: ff d0 0f 1f 00
[ ] SMP alternatives: ffffffff8100066f: orig: e8 cc 30 00 01
[ ] SMP alternatives: ffffffff8100066f: repl: ff d0 0f 1f 00
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/alternative.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -492,9 +492,15 @@ void __init_or_module noinline apply_ret
continue;
}
+ DPRINTK("retpoline at: %pS (%px) len: %d to: %pS",
+ addr, addr, insn.length,
+ addr + insn.length + insn.immediate.value);
+
len = patch_retpoline(addr, &insn, bytes);
if (len == insn.length) {
optimize_nops(bytes, len);
+ DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr);
+ DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
text_poke_early(addr, bytes, len);
}
}
next prev parent reply other threads:[~2021-10-27 8:58 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-27 8:52 [PATCH bpf-next 00/17] x86: Rewrite the retpoline rewrite logic Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 01/17] objtool: Handle __sanitize_cov*() tail calls Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 02/17] objtool: Classify symbols Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 03/17] objtool: Explicitly avoid self modifying code in .altinstr_replacement Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 04/17] objtool: Shrink struct instruction Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 05/17] objtool,x86: Replace alternatives with .retpoline_sites Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 06/17] x86/retpoline: Remove unused replacement symbols Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 07/17] x86/asm: Fix register order Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 08/17] x86/asm: Fixup odd GEN-for-each-reg.h usage Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 09/17] x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 10/17] x86/retpoline: Create a retpoline thunk array Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 11/17] x86/alternative: Implement .retpoline_sites support Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 12/17] x86/alternative: Handle Jcc __x86_indirect_thunk_\reg Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 13/17] x86/alternative: Try inline spectre_v2=retpoline,amd Peter Zijlstra
2021-10-27 8:52 ` Peter Zijlstra [this message]
2021-10-27 8:52 ` [PATCH bpf-next 15/17] x86,bugs: Unconditionally allow spectre_v2=retpoline,amd Peter Zijlstra
2021-10-27 8:52 ` [PATCH bpf-next 16/17] bpf, x86: Simplify computing label offsets Peter Zijlstra
2021-10-27 8:53 ` [PATCH bpf-next 17/17] bpf,x86: Respect X86_FEATURE_RETPOLINE* Peter Zijlstra
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