[PATCH 6/3] signal: Factor force_sig_perf out of perf_sigtrap

From: Eric W. Biederman
Date: Fri Apr 30 2021 - 19:43:32 EST



Separate generating the signal from deciding it needs to be sent.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
include/linux/sched/signal.h | 1 +
kernel/events/core.c | 11 ++---------
kernel/signal.c | 13 +++++++++++++
3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 7daa425f3055..1e2f61a1a512 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -318,6 +318,7 @@ int send_sig_mceerr(int code, void __user *, short, struct task_struct *);

int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
int force_sig_pkuerr(void __user *addr, u32 pkey);
+int force_sig_perf(void __user *addr, u32 type, u64 sig_data);

int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 928b166d888e..48ea8863183b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6394,8 +6394,6 @@ void perf_event_wakeup(struct perf_event *event)

static void perf_sigtrap(struct perf_event *event)
{
- struct kernel_siginfo info;
-
/*
* We'd expect this to only occur if the irq_work is delayed and either
* ctx->task or current has changed in the meantime. This can be the
@@ -6410,13 +6408,8 @@ static void perf_sigtrap(struct perf_event *event)
if (current->flags & PF_EXITING)
return;

- clear_siginfo(&info);
- info.si_signo = SIGTRAP;
- info.si_code = TRAP_PERF;
- info.si_errno = event->attr.type;
- info.si_perf = event->attr.sig_data;
- info.si_addr = (void __user *)event->pending_addr;
- force_sig_info(&info);
+ force_sig_perf((void __user *)event->pending_addr,
+ event->attr.type, event->attr.sig_data);
}

static void perf_pending_event_disable(struct perf_event *event)
diff --git a/kernel/signal.c b/kernel/signal.c
index 690921960d8b..5b1ad7f080ab 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1753,6 +1753,19 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
}
#endif

+int force_sig_perf(void __user *pending_addr, u32 type, u64 sig_data)
+{
+ struct kernel_siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = SIGTRAP;
+ info.si_errno = type;
+ info.si_code = TRAP_PERF;
+ info.si_addr = pending_addr;
+ info.si_perf = sig_data;
+ return force_sig_info(&info);
+}
+
#if IS_ENABLED(SPARC)
int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno)
{
--
2.30.1