On Wed, Jul 3, 2024 at 6:15 AM Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > > On Mon, 1 Jul 2024 15:39:25 -0700 > Andrii Nakryiko <andrii@xxxxxxxxxx> wrote: > > > It seems like uprobe_write_opcode() doesn't require writer locked > > mmap_sem, any lock (reader or writer) should be sufficient. This was > > established in a discussion in [0] and looking through existing code > > seems to confirm that there is no need for write-locked mmap_sem. > > > > Fix the comment to state this clearly. > > > > [0] https://lore.kernel.org/linux-trace-kernel/20240625190748.GC14254@xxxxxxxxxx/ > > > > Fixes: 29dedee0e693 ("uprobes: Add mem_cgroup_charge_anon() into uprobe_write_opcode()") > > nit: why this has Fixes but [01/12] doesn't? > > Should I pick both to fixes branch? I'd keep both of them in probes/for-next, tbh. They are not literally fixing anything, just cleaning up comments. I can drop the Fixes tag from this one, if you'd like. > > Thank you, > > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > > --- > > kernel/events/uprobes.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > > index 081821fd529a..f87049c08ee9 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 write. > > + * Called with mm->mmap_lock held for read or write. > > * Return 0 (success) or a negative errno. > > */ > > int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, > > -- > > 2.43.0 > > > > > -- > Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
