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| author | Borislav Petkov <bp@suse.de> | 2018-12-10 12:21:48 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-01-16 12:40:07 +0100 |
| commit | 1c1ed4731cc81942a5b25f284a85257573829b9e (patch) | |
| tree | ce2db38caffa432f63294de9b28581596fd7f4d2 /arch/x86/include/asm/alternative.h | |
| parent | 1c7fc5cbc33980acd13d668f1c8f0313d6ae9fd8 (diff) | |
| download | linux-stable-1c1ed4731cc81942a5b25f284a85257573829b9e.tar.gz linux-stable-1c1ed4731cc81942a5b25f284a85257573829b9e.tar.bz2 linux-stable-1c1ed4731cc81942a5b25f284a85257573829b9e.zip | |
x86/alternatives: Add macro comments
... so that when one stares at the .s output, one can find her way
around the resulting asm magic.
With it, 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>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: X86 ML <x86@kernel.org>
Link: https://lkml.kernel.org/r/20181211222326.14581-2-bp@alien8.de
Diffstat (limited to 'arch/x86/include/asm/alternative.h')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 0660e14690c8..373e2baca6ce 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -94,13 +94,12 @@ 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" /* @@ -116,7 +115,9 @@ 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" @@ -129,8 +130,9 @@ 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) \ |