linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, jpoimboe@redhat.com, andrew.cooper3@citrix.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	alexei.starovoitov@gmail.com, ndesaulniers@google.com
Subject: [PATCH 7/9] x86/alternative: Add debug prints to apply_retpolines()
Date: Wed, 13 Oct 2021 14:22:24 +0200	[thread overview]
Message-ID: <20211013123645.418209955@infradead.org> (raw)
In-Reply-To: 20211013122217.304265366@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 |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -487,9 +487,15 @@ 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);
 		}
 	}



  parent reply	other threads:[~2021-10-13 12:42 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-13 12:22 [PATCH 0/9] x86: Rewrite the retpoline rewrite logic Peter Zijlstra
2021-10-13 12:22 ` [PATCH 1/9] objtool,x86: Replace alternatives with .retpoline_sites Peter Zijlstra
2021-10-13 13:29   ` Borislav Petkov
2021-10-13 20:11   ` Josh Poimboeuf
2021-10-14 15:43     ` Peter Zijlstra
2021-10-13 12:22 ` [PATCH 2/9] x86/retpoline: Remove unused replacement symbols Peter Zijlstra
2021-10-13 12:22 ` [PATCH 3/9] x86/asm: Fix register order Peter Zijlstra
2021-10-13 20:15   ` Josh Poimboeuf
2021-10-13 12:22 ` [PATCH 4/9] x86/alternative: Implement .retpoline_sites support Peter Zijlstra
2021-10-13 14:38   ` Andrew Cooper
2021-10-13 15:12     ` Peter Zijlstra
2021-10-13 17:11       ` Andrew Cooper
2021-10-14 10:05       ` Peter Zijlstra
2021-10-13 20:39   ` Josh Poimboeuf
2021-10-13 21:20     ` Peter Zijlstra
2021-10-13 21:49       ` Josh Poimboeuf
2021-10-13 21:52         ` Josh Poimboeuf
2021-10-13 22:10         ` Peter Zijlstra
2021-10-13 22:47           ` Andrew Cooper
2021-10-13 20:52   ` Josh Poimboeuf
2021-10-13 21:00     ` Peter Zijlstra
2021-10-19 11:37     ` Peter Zijlstra
2021-10-19 16:46       ` Josh Poimboeuf
2021-10-19 16:49         ` Josh Poimboeuf
2021-10-20  8:25           ` Peter Zijlstra
2021-10-20  8:30           ` Peter Zijlstra
2021-10-13 21:11   ` Josh Poimboeuf
2021-10-13 21:43     ` Peter Zijlstra
2021-10-13 22:05       ` Josh Poimboeuf
2021-10-13 22:14         ` Peter Zijlstra
2021-10-15 14:24   ` Borislav Petkov
2021-10-15 16:56     ` Peter Zijlstra
2021-10-18 23:06       ` Alexander Lobakin
2021-10-19  0:25         ` Alexander Lobakin
2021-10-19  9:47           ` Alexander Lobakin
2021-10-19 10:16             ` Peter Zijlstra
2021-10-19 15:37               ` Sami Tolvanen
2021-10-19 18:00                 ` Alexander Lobakin
2021-10-19  9:40         ` Peter Zijlstra
2021-10-19 10:02           ` Peter Zijlstra
2021-10-13 12:22 ` [PATCH 5/9] x86/alternative: Handle Jcc __x86_indirect_thunk_\reg Peter Zijlstra
2021-10-13 20:11   ` Nick Desaulniers
2021-10-13 21:08     ` Peter Zijlstra
2021-10-13 12:22 ` [PATCH 6/9] x86/alternative: Try inline spectre_v2=retpoline,amd Peter Zijlstra
2021-10-13 12:22 ` Peter Zijlstra [this message]
2021-10-13 12:22 ` [PATCH 8/9] x86,bugs: Unconditionally allow spectre_v2=retpoline,amd Peter Zijlstra
2021-10-13 12:22 ` [PATCH 9/9] bpf,x86: Respect X86_FEATURE_RETPOLINE* Peter Zijlstra
2021-10-13 21:06   ` Josh Poimboeuf
2021-10-13 21:54     ` Peter Zijlstra
2021-10-14  9:46       ` Peter Zijlstra
2021-10-14  9:48         ` Peter Zijlstra
2021-10-20  7:34         ` Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211013123645.418209955@infradead.org \
    --to=peterz@infradead.org \
    --cc=alexei.starovoitov@gmail.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=jpoimboe@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ndesaulniers@google.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).