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 the changes in:
628d701f2de5b9a1 ("powerpc/dexcr: Add DEXCR prctl interface")
6b9391b581fddd85 ("riscv: Include riscv_set_icache_flush_ctx prctl")
That adds some PowerPC and a RISC-V specific prctl options:
$ tools/perf/trace/beauty/prctl_option.sh > before
$ cp include/uapi/linux/prctl.h tools/perf/trace/beauty/include/uapi/linux/prctl.h
$ tools/perf/trace/beauty/prctl_option.sh > after
$ diff -u before after
--- before 2024-05-27 12:14:21.358032781 -0300
+++ after 2024-05-27 12:14:32.364530185 -0300
@@ -65,6 +65,9 @@
[68] = "GET_MEMORY_MERGE",
[69] = "RISCV_V_SET_CONTROL",
[70] = "RISCV_V_GET_CONTROL",
+ [71] = "RISCV_SET_ICACHE_FLUSH_CTX",
+ [72] = "PPC_GET_DEXCR",
+ [73] = "PPC_SET_DEXCR",
};
static const char *prctl_set_mm_options[] = {
[1] = "START_CODE",
$
That now will be used to decode the syscall option and also to compose
filters, for instance:
[root@five ~]# perf trace -e syscalls:sys_enter_prctl --filter option==SET_NAME
0.000 Isolated Servi/3474327 syscalls:sys_enter_prctl(option: SET_NAME, arg2: 0x7f23f13b7aee)
0.032 DOM Worker/3474327 syscalls:sys_enter_prctl(option: SET_NAME, arg2: 0x7f23deb25670)
7.920 :3474328/3474328 syscalls:sys_enter_prctl(option: SET_NAME, arg2: 0x7f23e24fbb10)
7.935 StreamT~s #374/3474328 syscalls:sys_enter_prctl(option: SET_NAME, arg2: 0x7f23e24fb970)
8.400 Isolated Servi/3474329 syscalls:sys_enter_prctl(option: SET_NAME, arg2: 0x7f23e24bab10)
8.418 StreamT~s #374/3474329 syscalls:sys_enter_prctl(option: SET_NAME, arg2: 0x7f23e24ba970)
^C[root@five ~]#
This addresses this perf build warning:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/linux/prctl.h include/uapi/linux/prctl.h
Cc: Adrian Hunter <[email protected]>
Cc: Benjamin Gray <[email protected]>
Cc: Charlie Jenkins <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
.../trace/beauty/include/uapi/linux/prctl.h | 22 +++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/tools/perf/trace/beauty/include/uapi/linux/prctl.h b/tools/perf/trace/beauty/include/uapi/linux/prctl.h
index 370ed14b1ae0928c..35791791a879b288 100644
--- a/tools/perf/trace/beauty/include/uapi/linux/prctl.h
+++ b/tools/perf/trace/beauty/include/uapi/linux/prctl.h
@@ -306,4 +306,26 @@ struct prctl_mm_map {
# define PR_RISCV_V_VSTATE_CTRL_NEXT_MASK 0xc
# define PR_RISCV_V_VSTATE_CTRL_MASK 0x1f
+#define PR_RISCV_SET_ICACHE_FLUSH_CTX 71
+# define PR_RISCV_CTX_SW_FENCEI_ON 0
+# define PR_RISCV_CTX_SW_FENCEI_OFF 1
+# define PR_RISCV_SCOPE_PER_PROCESS 0
+# define PR_RISCV_SCOPE_PER_THREAD 1
+
+/* PowerPC Dynamic Execution Control Register (DEXCR) controls */
+#define PR_PPC_GET_DEXCR 72
+#define PR_PPC_SET_DEXCR 73
+/* DEXCR aspect to act on */
+# define PR_PPC_DEXCR_SBHE 0 /* Speculative branch hint enable */
+# define PR_PPC_DEXCR_IBRTPD 1 /* Indirect branch recurrent target prediction disable */
+# define PR_PPC_DEXCR_SRAPD 2 /* Subroutine return address prediction disable */
+# define PR_PPC_DEXCR_NPHIE 3 /* Non-privileged hash instruction enable */
+/* Action to apply / return */
+# define PR_PPC_DEXCR_CTRL_EDITABLE 0x1 /* Aspect can be modified with PR_PPC_SET_DEXCR */
+# define PR_PPC_DEXCR_CTRL_SET 0x2 /* Set the aspect for this process */
+# define PR_PPC_DEXCR_CTRL_CLEAR 0x4 /* Clear the aspect for this process */
+# define PR_PPC_DEXCR_CTRL_SET_ONEXEC 0x8 /* Set the aspect on exec */
+# define PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC 0x10 /* Clear the aspect on exec */
+# define PR_PPC_DEXCR_CTRL_MASK 0x1f
+
#endif /* _LINUX_PRCTL_H */
--
2.45.1