6.17-stable review patch. If anyone has any objections, please let me know.
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From: Steven Rostedt rostedt@goodmis.org
[ Upstream commit 90942f9fac05702065ff82ed0bade0d08168d4ea ]
To determine if a task is a kernel thread or not, it is more reliable to use (current->flags & (PF_KTHREAD|PF_USER_WORKERi)) than to rely on current->mm being NULL. That is because some kernel tasks (io_uring helpers) may have a mm field.
Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lore.kernel.org/r/20250820180428.592367294@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/events/callchain.c | 6 +++--- kernel/events/core.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 6c83ad674d010..decff7266cfbd 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -242,10 +242,10 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
if (user) { if (!user_mode(regs)) { - if (current->mm) - regs = task_pt_regs(current); - else + if (current->flags & (PF_KTHREAD | PF_USER_WORKER)) regs = NULL; + else + regs = task_pt_regs(current); }
if (regs) { diff --git a/kernel/events/core.c b/kernel/events/core.c index 6e9427c4aaff7..a3dc79ec6f879 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7440,7 +7440,7 @@ static void perf_sample_regs_user(struct perf_regs *regs_user, if (user_mode(regs)) { regs_user->abi = perf_reg_abi(current); regs_user->regs = regs; - } else if (!(current->flags & PF_KTHREAD)) { + } else if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER))) { perf_get_regs_user(regs_user, regs); } else { regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; @@ -8080,7 +8080,7 @@ static u64 perf_virt_to_phys(u64 virt) * Try IRQ-safe get_user_page_fast_only first. * If failed, leave phys_addr as 0. */ - if (current->mm != NULL) { + if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER))) { struct page *p;
pagefault_disable();