From: Oleg Nesterov <oleg@redhat.com>
To: andrii@kernel.org, mhiramat@kernel.org, peterz@infradead.org
Cc: clm@meta.com, jolsa@kernel.org, mingo@kernel.org,
paulmck@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] uprobes: is_trap_at_addr: don't use get_user_pages_remote()
Date: Wed, 10 Jul 2024 16:01:08 +0200 [thread overview]
Message-ID: <20240710140108.GB1084@redhat.com> (raw)
In-Reply-To: <20240710140017.GA1074@redhat.com>
get_user_pages_remote() and the comment above it make no sense.
There is no task_struct passed into get_user_pages_remote() anymore, and
nowadays mm_account_fault() increments the current->min/maj_flt counters
regardless of FAULT_FLAG_REMOTE.
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
kernel/events/uprobes.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index d52b624a50fa..1bdf386485d4 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -453,7 +453,7 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm,
* @vaddr: the virtual address to store the opcode.
* @opcode: opcode to be written at @vaddr.
*
- * Called with mm->mmap_lock held for read or write.
+ * Called with mm->mmap_lock held.
* Return 0 (success) or a negative errno.
*/
int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
@@ -2024,13 +2024,7 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
if (likely(result == 0))
goto out;
- /*
- * The NULL 'tsk' here ensures that any faults that occur here
- * will not be accounted to the task. 'mm' *is* current->mm,
- * but we treat this as a 'remote' access since it is
- * essentially a kernel access to the memory.
- */
- result = get_user_pages_remote(mm, vaddr, 1, FOLL_FORCE, &page, NULL);
+ result = get_user_pages(vaddr, 1, FOLL_FORCE, &page);
if (result < 0)
return result;
--
2.25.1.362.g51ebf55
next prev parent reply other threads:[~2024-07-10 14:02 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-10 14:00 [PATCH 0/2] uprobes: document mmap_lock, don't abuse get_user_pages_remote() Oleg Nesterov
2024-07-10 14:00 ` [PATCH 1/2] uprobes: document the usage of mm->mmap_lock Oleg Nesterov
2024-07-10 14:51 ` Masami Hiramatsu
2024-07-10 15:10 ` Oleg Nesterov
2024-07-11 0:07 ` Masami Hiramatsu
2024-07-11 9:49 ` Oleg Nesterov
2024-07-11 14:19 ` Masami Hiramatsu
2024-07-11 15:25 ` Oleg Nesterov
2024-07-10 14:01 ` Oleg Nesterov [this message]
2024-07-10 15:15 ` [PATCH 2/2] uprobes: is_trap_at_addr: don't use get_user_pages_remote() Andrii Nakryiko
2024-07-10 16:30 ` [PATCH 0/3] uprobes: future cleanups for review Oleg Nesterov
2024-07-10 16:30 ` [PATCH 1/3] uprobes: kill uprobe_register_refctr() Oleg Nesterov
2024-07-10 18:03 ` Andrii Nakryiko
2024-07-10 19:32 ` Oleg Nesterov
2024-07-10 16:31 ` [PATCH 2/3] uprobes: simplify error handling for alloc_uprobe() Oleg Nesterov
2024-07-11 15:18 ` Masami Hiramatsu
2024-07-10 16:31 ` [PATCH 3/3] uprobes: make uprobe_register() return struct uprobe * Oleg Nesterov
2024-07-10 16:48 ` Jiri Olsa
2024-07-10 18:23 ` Andrii Nakryiko
2024-07-10 19:38 ` Jiri Olsa
2024-07-10 19:48 ` Andrii Nakryiko
2024-07-10 19:20 ` Oleg Nesterov
2024-07-10 18:21 ` Andrii Nakryiko
2024-07-10 20:16 ` Oleg Nesterov
2024-07-10 20:46 ` Andrii Nakryiko
2024-07-11 9:26 ` Oleg Nesterov
2024-07-11 17:11 ` Andrii Nakryiko
2024-07-11 18:26 ` Oleg Nesterov
2024-07-11 8:27 ` [PATCH 0/3] uprobes: future cleanups for review Peter Zijlstra
2024-07-11 8:45 ` Oleg Nesterov
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