Re: [PATCH v3 2/5] perf: Hoist perf_instruction_pointer() and perf_misc_flags()

Madhavan Srinivasan
2024-09-17T05:38:19Z

On 9/13/24 2:21 AM, Colton Lewis wrote:
> For clarity, rename the arch-specific definitions of these functions
> to perf_arch_* to denote they are arch-specifc. Define the
> generic-named functions in one place where they can call the
> arch-specific ones as needed.
>
> Signed-off-by: Colton Lewis <coltonlewis@google.com>
> ---
> arch/arm64/include/asm/perf_event.h | 6 +++---
> arch/arm64/kernel/perf_callchain.c | 4 ++--
> arch/powerpc/include/asm/perf_event_server.h | 6 +++---
> arch/powerpc/perf/core-book3s.c | 4 ++--
> arch/s390/include/asm/perf_event.h | 6 +++---
> arch/s390/kernel/perf_event.c | 4 ++--
> arch/x86/events/core.c | 4 ++--
> arch/x86/include/asm/perf_event.h | 10 +++++-----
> include/linux/perf_event.h | 9 ++++++---
> kernel/events/core.c | 10 ++++++++++
> 10 files changed, 38 insertions(+), 25 deletions(-)
>
> diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h
> index eb7071c9eb34..31a5584ed423 100644
> --- a/arch/arm64/include/asm/perf_event.h
> +++ b/arch/arm64/include/asm/perf_event.h
> @@ -11,9 +11,9 @@
>
> #ifdef CONFIG_PERF_EVENTS
> struct pt_regs;
> -extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> -extern unsigned long perf_misc_flags(struct pt_regs *regs);
> -#define perf_misc_flags(regs) perf_misc_flags(regs)
> +extern unsigned long perf_arch_instruction_pointer(struct pt_regs *regs);
> +extern unsigned long perf_arch_misc_flags(struct pt_regs *regs);
> +#define perf_arch_misc_flags(regs) perf_misc_flags(regs)
> #define perf_arch_bpf_user_pt_regs(regs) &regs->user_regs
> #endif
>
> diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
> index e8ed5673f481..01a9d08fc009 100644
> --- a/arch/arm64/kernel/perf_callchain.c
> +++ b/arch/arm64/kernel/perf_callchain.c
> @@ -39,7 +39,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
> arch_stack_walk(callchain_trace, entry, current, regs);
> }
>
> -unsigned long perf_instruction_pointer(struct pt_regs *regs)
> +unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
> {
> if (perf_guest_state())
> return perf_guest_get_ip();
> @@ -47,7 +47,7 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
> return instruction_pointer(regs);
> }
>
> -unsigned long perf_misc_flags(struct pt_regs *regs)
> +unsigned long perf_arch_misc_flags(struct pt_regs *regs)
> {
> unsigned int guest_state = perf_guest_state();
> int misc = 0;
> diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
> index 5995614e9062..41587d3f8446 100644
> --- a/arch/powerpc/include/asm/perf_event_server.h
> +++ b/arch/powerpc/include/asm/perf_event_server.h
> @@ -102,8 +102,8 @@ struct power_pmu {
> int __init register_power_pmu(struct power_pmu *pmu);
>
> struct pt_regs;
> -extern unsigned long perf_misc_flags(struct pt_regs *regs);
> -extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> +extern unsigned long perf_arch_misc_flags(struct pt_regs *regs);
> +extern unsigned long perf_arch_instruction_pointer(struct pt_regs *regs);
> extern unsigned long int read_bhrb(int n);
>
> /*
> @@ -111,7 +111,7 @@ extern unsigned long int read_bhrb(int n);
> * if we have hardware PMU support.
> */
> #ifdef CONFIG_PPC_PERF_CTRS
> -#define perf_misc_flags(regs) perf_misc_flags(regs)
> +#define perf_arch_misc_flags(regs) perf_misc_flags(regs)
> #endif
>
Compilation fails with

In file included from /linux/arch/powerpc/include/asm/perf_event.h:14,
from /linux/include/linux/perf_event.h:25,
from /linux/arch/powerpc/perf/core-book3s.c:10:
/linux/arch/powerpc/include/asm/perf_event_server.h:114:41: error:
conflicting types for 'perf_misc_flags'; have 'long unsigned int(struct
pt_regs *)'
114 | #define perf_arch_misc_flags(regs)      perf_misc_flags(regs)
|                                         ^~~~~~~~~~~~~~~
/linux/arch/powerpc/perf/core-book3s.c:2335:15: note: in expansion of
macro 'perf_arch_misc_flags'
2335 | unsigned long perf_arch_misc_flags(struct pt_regs *regs)
|               ^~~~~~~~~~~~~~~~~~~~
/linux/include/linux/perf_event.h:1630:22: note: previous declaration of
'perf_misc_flags' with type 'long unsigned int(struct perf_event *,
struct pt_regs *)'
1630 | extern unsigned long perf_misc_flags(struct perf_event *event,
struct pt_regs *regs);
|                      ^~~~~~~~~~~~~~~

This fixes the fail

--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -111,7 +111,7 @@ extern unsigned long int read_bhrb(int n);
* if we have hardware PMU support.
*/
#ifdef CONFIG_PPC_PERF_CTRS
-#define perf_arch_misc_flags(regs) perf_misc_flags(regs)
+#define perf_arch_misc_flags(regs) perf_arch_misc_flags(regs)
#endif

/*

> /*
> diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
> index 42867469752d..dc01aa604cc1 100644
> --- a/arch/powerpc/perf/core-book3s.c
> +++ b/arch/powerpc/perf/core-book3s.c
> @@ -2332,7 +2332,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
> * Called from generic code to get the misc flags (i.e. processor mode)
> * for an event_id.
> */
> -unsigned long perf_misc_flags(struct pt_regs *regs)
> +unsigned long perf_arch_misc_flags(struct pt_regs *regs)
> {
> u32 flags = perf_get_misc_flags(regs);
>
> @@ -2346,7 +2346,7 @@ unsigned long perf_misc_flags(struct pt_regs *regs)
> * Called from generic code to get the instruction pointer
> * for an event_id.
> */
> -unsigned long perf_instruction_pointer(struct pt_regs *regs)
> +unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
> {
> unsigned long siar = mfspr(SPRN_SIAR);
>
> diff --git a/arch/s390/include/asm/perf_event.h b/arch/s390/include/asm/perf_event.h
> index 9917e2717b2b..f2d83289ec7a 100644
> --- a/arch/s390/include/asm/perf_event.h
> +++ b/arch/s390/include/asm/perf_event.h
> @@ -37,9 +37,9 @@ extern ssize_t cpumf_events_sysfs_show(struct device *dev,
>
> /* Perf callbacks */
> struct pt_regs;
> -extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> -extern unsigned long perf_misc_flags(struct pt_regs *regs);
> -#define perf_misc_flags(regs) perf_misc_flags(regs)
> +extern unsigned long perf_arch_instruction_pointer(struct pt_regs *regs);
> +extern unsigned long perf_arch_misc_flags(struct pt_regs *regs);
> +#define perf_arch_misc_flags(regs) perf_misc_flags(regs)
> #define perf_arch_bpf_user_pt_regs(regs) &regs->user_regs
>
> /* Perf pt_regs extension for sample-data-entry indicators */
> diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
> index 5fff629b1a89..f9000ab49f4a 100644
> --- a/arch/s390/kernel/perf_event.c
> +++ b/arch/s390/kernel/perf_event.c
> @@ -57,7 +57,7 @@ static unsigned long instruction_pointer_guest(struct pt_regs *regs)
> return sie_block(regs)->gpsw.addr;
> }
>
> -unsigned long perf_instruction_pointer(struct pt_regs *regs)
> +unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
> {
> return is_in_guest(regs) ? instruction_pointer_guest(regs)
> : instruction_pointer(regs);
> @@ -84,7 +84,7 @@ static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
> return flags;
> }
>
> -unsigned long perf_misc_flags(struct pt_regs *regs)
> +unsigned long perf_arch_misc_flags(struct pt_regs *regs)
> {
> /* Check if the cpum_sf PMU has created the pt_regs structure.
> * In this case, perf misc flags can be easily extracted. Otherwise,
> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
> index be01823b1bb4..760ad067527c 100644
> --- a/arch/x86/events/core.c
> +++ b/arch/x86/events/core.c
> @@ -2940,7 +2940,7 @@ static unsigned long code_segment_base(struct pt_regs *regs)
> return 0;
> }
>
> -unsigned long perf_instruction_pointer(struct pt_regs *regs)
> +unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
> {
> if (perf_guest_state())
> return perf_guest_get_ip();
> @@ -2948,7 +2948,7 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
> return regs->ip + code_segment_base(regs);
> }
>
> -unsigned long perf_misc_flags(struct pt_regs *regs)
> +unsigned long perf_arch_misc_flags(struct pt_regs *regs)
> {
> unsigned int guest_state = perf_guest_state();
> int misc = 0;
> diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
> index 91b73571412f..feb87bf3d2e9 100644
> --- a/arch/x86/include/asm/perf_event.h
> +++ b/arch/x86/include/asm/perf_event.h
> @@ -536,15 +536,15 @@ struct x86_perf_regs {
> u64 *xmm_regs;
> };
>
> -extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> -extern unsigned long perf_misc_flags(struct pt_regs *regs);
> -#define perf_misc_flags(regs) perf_misc_flags(regs)
> +extern unsigned long perf_arch_instruction_pointer(struct pt_regs *regs);
> +extern unsigned long perf_arch_misc_flags(struct pt_regs *regs);
> +#define perf_arch_misc_flags(regs) perf_arch_misc_flags(regs)
>
> #include <asm/stacktrace.h>
>
> /*
> - * We abuse bit 3 from flags to pass exact information, see perf_misc_flags
> - * and the comment with PERF_EFLAGS_EXACT.
> + * We abuse bit 3 from flags to pass exact information, see
> + * perf_arch_misc_flags() and the comment with PERF_EFLAGS_EXACT.
> */
> #define perf_arch_fetch_caller_regs(regs, __ip) { \
> (regs)->ip = (__ip); \
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 1a8942277dda..d061e327ad54 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -1633,10 +1633,13 @@ extern void perf_tp_event(u16 event_type, u64 count, void *record,
> struct task_struct *task);
> extern void perf_bp_event(struct perf_event *event, void *data);
>
> -#ifndef perf_misc_flags
> -# define perf_misc_flags(regs) \
> +extern unsigned long perf_misc_flags(struct pt_regs *regs);
> +extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> +
> +#ifndef perf_arch_misc_flags
> +# define perf_arch_misc_flags(regs) \
> (user_mode(regs) ? PERF_RECORD_MISC_USER : PERF_RECORD_MISC_KERNEL)
> -# define perf_instruction_pointer(regs) instruction_pointer(regs)
> +# define perf_arch_instruction_pointer(regs) instruction_pointer(regs)
> #endif
> #ifndef perf_arch_bpf_user_pt_regs
> # define perf_arch_bpf_user_pt_regs(regs) regs
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 8a6c6bbcd658..eeabbf791a8c 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6921,6 +6921,16 @@ void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
> EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
> #endif
>
> +unsigned long perf_misc_flags(struct pt_regs *regs)
> +{
> + return perf_arch_misc_flags(regs);
> +}
> +
> +unsigned long perf_instruction_pointer(struct pt_regs *regs)
> +{
> + return perf_arch_instruction_pointer(regs);
> +}
> +
> static void
> perf_output_sample_regs(struct perf_output_handle *handle,
> struct pt_regs *regs, u64 mask)