From: Borislav Petkov <bp@alien8.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: X86 ML <x86@kernel.org>, Andy Lutomirski <luto@amacapital.net>,
"H. Peter Anvin" <hpa@zytor.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: [RFC PATCH 1/4] x86/alternatives: Add macro comments
Date: Tue, 11 Dec 2018 23:23:23 +0100 [thread overview]
Message-ID: <20181211222326.14581-2-bp@alien8.de> (raw)
In-Reply-To: <20181211222326.14581-1-bp@alien8.de>
From: Borislav Petkov <bp@suse.de>
... so that when one stares at the .s output, one can find her way
around the resulting asm magic.
For example, ALTERNATIVE looks like this now:
# ALT: oldnstr
661:
...
662:
# ALT: padding
.skip ...
663:
.pushsection .altinstructions,"a"
...
.popsection
.pushsection .altinstr_replacement, "ax"
# ALT: replacement 1
6641:
...
6651:
.popsection
Merge __OLDINSTR() into OLDINSTR(), while at it.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/include/asm/alternative.h | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index d7faa16622d8..8d38b296a18a 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -87,13 +87,12 @@ static inline int alternatives_text_reserved(void *start, void *end)
#define alt_total_slen alt_end_marker"b-661b"
#define alt_rlen(num) e_replacement(num)"f-"b_replacement(num)"f"
-#define __OLDINSTR(oldinstr, num) \
+#define OLDINSTR(oldinstr, num) \
+ "# ALT: oldnstr\n" \
"661:\n\t" oldinstr "\n662:\n" \
+ "# ALT: padding\n" \
".skip -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * " \
- "((" alt_rlen(num) ")-(" alt_slen ")),0x90\n"
-
-#define OLDINSTR(oldinstr, num) \
- __OLDINSTR(oldinstr, num) \
+ "((" alt_rlen(num) ")-(" alt_slen ")),0x90\n" \
alt_end_marker ":\n"
/*
@@ -109,7 +108,9 @@ static inline int alternatives_text_reserved(void *start, void *end)
* additionally longer than the first replacement alternative.
*/
#define OLDINSTR_2(oldinstr, num1, num2) \
+ "# ALT: oldinstr2\n" \
"661:\n\t" oldinstr "\n662:\n" \
+ "# ALT: padding2\n" \
".skip -((" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")) > 0) * " \
"(" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")), 0x90\n" \
alt_end_marker ":\n"
@@ -122,8 +123,9 @@ static inline int alternatives_text_reserved(void *start, void *end)
" .byte " alt_rlen(num) "\n" /* replacement len */ \
" .byte " alt_pad_len "\n" /* pad len */
-#define ALTINSTR_REPLACEMENT(newinstr, feature, num) /* replacement */ \
- b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n\t"
+#define ALTINSTR_REPLACEMENT(newinstr, feature, num) /* replacement */ \
+ "# ALT: replacement " #num "\n" \
+ b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n"
/* alternative assembly primitive: */
#define ALTERNATIVE(oldinstr, newinstr, feature) \
--
2.19.1
next prev parent reply other threads:[~2018-12-11 22:23 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 22:23 [RFC PATCH 0/4] x86/alternative: Add ALTERNATIVE_3 Borislav Petkov
2018-12-11 22:23 ` Borislav Petkov [this message]
2019-01-16 11:57 ` [tip:x86/alternatives] x86/alternatives: Add macro comments tip-bot for Borislav Petkov
2018-12-11 22:23 ` [RFC PATCH 2/4] x86/alternatives: Print containing function Borislav Petkov
2019-01-16 11:58 ` [tip:x86/alternatives] " tip-bot for Borislav Petkov
2018-12-11 22:23 ` [RFC PATCH 3/4] x86/alternatives: Add an ALTERNATIVE_3() macro Borislav Petkov
2019-01-16 11:59 ` [tip:x86/alternatives] " tip-bot for Borislav Petkov
2018-12-11 22:23 ` [RFC PATCH 4/4] x86/TSC: Use RDTSCP Borislav Petkov
2018-12-11 22:59 ` Andy Lutomirski
2018-12-11 23:12 ` Lendacky, Thomas
2018-12-11 23:39 ` Borislav Petkov
2018-12-12 2:24 ` Andy Lutomirski
2018-12-12 9:59 ` Peter Zijlstra
2018-12-12 12:02 ` Andrea Parri
2018-12-12 10:08 ` Borislav Petkov
2018-12-12 18:07 ` Andy Lutomirski
2018-12-12 18:44 ` Borislav Petkov
2018-12-12 18:50 ` Andy Lutomirski
2018-12-12 20:00 ` Borislav Petkov
2018-12-12 20:09 ` Andy Lutomirski
2018-12-12 20:29 ` Borislav Petkov
2018-12-14 13:39 ` David Laight
2018-12-15 18:53 ` Andy Lutomirski
2018-12-12 14:15 ` Lendacky, Thomas
2018-12-12 14:18 ` Lendacky, Thomas
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