tldr; Just FYI, I'm carrying this on the perf tools tree.
Full explanation:
There used to be no copies, with tools/ code using kernel headers
directly. From time to time tools/perf/ broke due to legitimate kernel
hacking. At some point Linus complained about such direct usage. Then we
adopted the current model.
The way these headers are used in perf are not restricted to just
including them to compile something.
There are sometimes used in scripts that convert defines into string
tables, etc, so some change may break one of these scripts, or new MSRs
may use some different #define pattern, etc.
E.g.:
$ ls -1 tools/perf/trace/beauty/*.sh | head -5
tools/perf/trace/beauty/arch_errno_names.sh
tools/perf/trace/beauty/drm_ioctl.sh
tools/perf/trace/beauty/fadvise.sh
tools/perf/trace/beauty/fsconfig.sh
tools/perf/trace/beauty/fsmount.sh
$
$ tools/perf/trace/beauty/fadvise.sh
static const char *fadvise_advices[] = {
[0] = "NORMAL",
[1] = "RANDOM",
[2] = "SEQUENTIAL",
[3] = "WILLNEED",
[4] = "DONTNEED",
[5] = "NOREUSE",
};
$
The tools/perf/check-headers.sh script, part of the tools/ build
process, points out changes in the original files.
So its important not to touch the copies in tools/ when doing changes in
the original kernel headers, that will be done later, when
check-headers.sh inform about the change to the perf tools hackers.
To pick up the changes from these csets:
53bc516ade85a764 ("x86/msr: Move ARCH_CAP_XAPIC_DISABLE bit definition to its rightful place")
That patch just move definitions around, so this just silences this perf
build warning:
Warning: Kernel ABI header differences:
diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.
Cc: Adrian Hunter <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Pawan Gupta <[email protected]>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/arch/x86/include/asm/msr-index.h | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index e72c2b87295799af..e022e6eb766c6405 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -170,6 +170,10 @@
* CPU is not affected by Branch
* History Injection.
*/
+#define ARCH_CAP_XAPIC_DISABLE BIT(21) /*
+ * IA32_XAPIC_DISABLE_STATUS MSR
+ * supported
+ */
#define ARCH_CAP_PBRSB_NO BIT(24) /*
* Not susceptible to Post-Barrier
* Return Stack Buffer Predictions.
@@ -192,11 +196,6 @@
* File.
*/
-#define ARCH_CAP_XAPIC_DISABLE BIT(21) /*
- * IA32_XAPIC_DISABLE_STATUS MSR
- * supported
- */
-
#define MSR_IA32_FLUSH_CMD 0x0000010b
#define L1D_FLUSH BIT(0) /*
* Writeback and invalidate the
--
2.44.0