From d32bf877c0c3ebc345b444cbe009b3f44f9f8073 Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Wed, 27 May 2026 15:55:06 -0700 Subject: [PATCH] perf/core: out-of-line and export perf_allow_cpu/tracepoint() These helpers are static inline in and reach into sysctl_perf_event_paranoid and security_perf_event_open(), neither of which is itself exported. The perf_allow_* trio is therefore asymmetric: built-in callers can use any of the three, but modular code can only call perf_allow_kernel(). Move both bodies into kernel/events/core.c next to perf_allow_kernel() and export them with EXPORT_SYMBOL_GPL, following the shape of commit 5e9629d0ae97 ("drivers/perf: arm_spe: Use perf_allow_kernel() for permissions"). Existing in-tree callers live in built-in arch and tracing code, so the change is invisible to them. Provide !CONFIG_PERF_EVENTS stubs that fall back to perfmon_capable(), so the helpers stay callable when perf is compiled out. Signed-off-by: John Hubbard Reviewed-by: Ashutosh Dixit Link: https://patch.msgid.link/20260527225507.2044027-2-ashutosh.dixit@intel.com Signed-off-by: Ashutosh Dixit --- include/linux/perf_event.h | 31 +++++++++++++++---------------- kernel/events/core.c | 18 ++++++++++++++++++ 2 files changed, 33 insertions(+), 16 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 48d851fbd8ea..5842552294c1 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1791,22 +1791,8 @@ static inline int perf_is_paranoid(void) } extern int perf_allow_kernel(void); - -static inline int perf_allow_cpu(void) -{ - if (sysctl_perf_event_paranoid > 0 && !perfmon_capable()) - return -EACCES; - - return security_perf_event_open(PERF_SECURITY_CPU); -} - -static inline int perf_allow_tracepoint(void) -{ - if (sysctl_perf_event_paranoid > -1 && !perfmon_capable()) - return -EPERM; - - return security_perf_event_open(PERF_SECURITY_TRACEPOINT); -} +extern int perf_allow_cpu(void); +extern int perf_allow_tracepoint(void); extern int perf_exclude_event(struct perf_event *event, struct pt_regs *regs); @@ -2023,6 +2009,19 @@ perf_event_pause(struct perf_event *event, bool reset) { return 0; } static inline int perf_exclude_event(struct perf_event *event, struct pt_regs *regs) { return 0; } +static inline int perf_allow_kernel(void) +{ + return perfmon_capable() ? 0 : -EACCES; +} +static inline int perf_allow_cpu(void) +{ + return perfmon_capable() ? 0 : -EACCES; +} +static inline int perf_allow_tracepoint(void) +{ + return perfmon_capable() ? 0 : -EPERM; +} + #endif /* !CONFIG_PERF_EVENTS */ #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL) diff --git a/kernel/events/core.c b/kernel/events/core.c index 6d1f8bad7e1c..735e502beb96 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -14691,6 +14691,24 @@ int perf_allow_kernel(void) } EXPORT_SYMBOL_GPL(perf_allow_kernel); +int perf_allow_cpu(void) +{ + if (sysctl_perf_event_paranoid > 0 && !perfmon_capable()) + return -EACCES; + + return security_perf_event_open(PERF_SECURITY_CPU); +} +EXPORT_SYMBOL_GPL(perf_allow_cpu); + +int perf_allow_tracepoint(void) +{ + if (sysctl_perf_event_paranoid > -1 && !perfmon_capable()) + return -EPERM; + + return security_perf_event_open(PERF_SECURITY_TRACEPOINT); +} +EXPORT_SYMBOL_GPL(perf_allow_tracepoint); + /* * Inherit an event from parent task to child task. *