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

Colton Lewis
2024-09-19T18:44:33Z

Madhavan Srinivasan <maddy@linux.ibm.com> writes:

> 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

>  /*

Thanks. Done

>> /*
>> 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)