On 05/20, Masami Hiramatsu wrote: > > On Thu, 15 May 2025 14:10:58 +0200 > Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > > > Currently unapply_uprobe takes mmap_read_lock, but it might call > > remove_breakpoint which eventually changes user pages. > > > > Current code writes either breakpoint or original instruction, so > > it can probably go away with that, but with the upcoming change that > > writes multiple instructions on the probed address we need to ensure > > that any update to mm's pages is exclusive. > > > > So, this is a bugfix, right? No, mmap_read_lock() is fine. To remind, this was already discussed with you, see [PATCH 02/12] uprobes: grab write mmap lock in unapply_uprobe() https://lore.kernel.org/all/20240625002144.3485799-3-andrii@xxxxxxxxxx/ And you even reviewed this patch [PATCH 1/2] uprobes: document the usage of mm->mmap_lock https://lore.kernel.org/all/20240710140045.GA1084@xxxxxxxxxx/ But, as the changelog explains, this patch is needed for the upcoming changes. -------------------------------------------------------------------------- Just in case... I'll try to read this series tomorrow, but at first glance this version addresses all my concerns. Oleg.
