On Tue, Aug 26, 2025 at 10:25:29AM +0200, Jiri Olsa wrote:
> On Tue, Aug 26, 2025 at 06:51:58AM +0100, David Laight wrote:
> > On Thu, 21 Aug 2025 14:28:24 +0200
> > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> > > Make is_optimized() return a tri-state and avoid return through
> > > argument. This simplifies things a little.
> > >
> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> > > ---
> > > arch/x86/kernel/uprobes.c | 34 +++++++++++++---------------------
> > > 1 file changed, 13 insertions(+), 21 deletions(-)
> > >
> > > --- a/arch/x86/kernel/uprobes.c
> > > +++ b/arch/x86/kernel/uprobes.c
> > > @@ -1047,7 +1047,7 @@ static bool __is_optimized(uprobe_opcode
> > > return __in_uprobe_trampoline(vaddr + 5 + call->raddr);
> > > }
> > >
> > > -static int is_optimized(struct mm_struct *mm, unsigned long vaddr, bool *optimized)
> > > +static int is_optimized(struct mm_struct *mm, unsigned long vaddr)
> > > {
> > > uprobe_opcode_t insn[5];
> > > int err;
> > > @@ -1055,8 +1055,7 @@ static int is_optimized(struct mm_struct
> > > err = copy_from_vaddr(mm, vaddr, &insn, 5);
> > > if (err)
> > > return err;
> > > - *optimized = __is_optimized((uprobe_opcode_t *)&insn, vaddr);
> > > - return 0;
> > > + return __is_optimized((uprobe_opcode_t *)&insn, vaddr);
> > > }
> > >
> > > static bool should_optimize(struct arch_uprobe *auprobe)
> > > @@ -1069,17 +1068,14 @@ int set_swbp(struct arch_uprobe *auprobe
> > > unsigned long vaddr)
> > > {
> > > if (should_optimize(auprobe)) {
> > > - bool optimized = false;
> > > - int err;
> > > -
> > > /*
> > > * We could race with another thread that already optimized the probe,
> > > * so let's not overwrite it with int3 again in this case.
> > > */
> > > - err = is_optimized(vma->vm_mm, vaddr, &optimized);
> > > - if (err)
> > > - return err;
> > > - if (optimized)
> > > + int ret = is_optimized(vma->vm_mm, vaddr);
> > > + if (ret < 0)
> > > + return ret;
> > > + if (ret)
> > > return 0;
> >
> > Looks like you should swap over 0 and 1.
> > That would then be: if (ret <= 0) return ret;
>
> hum, but if it's not optimized (ret == 0) we need to follow up with
> installing breakpoint through following uprobe_write_opcode call
ah u meant to swap the whole thing.. got it
>
> also I noticed we mix int/bool return, perhaps we could do fix below
>
> jirka
>
>
> ---
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index 0a8c0a4a5423..853abb2a5638 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -1064,7 +1064,7 @@ static int is_optimized(struct mm_struct *mm, unsigned long vaddr)
> err = copy_from_vaddr(mm, vaddr, &insn, 5);
> if (err)
> return err;
> - return __is_optimized((uprobe_opcode_t *)&insn, vaddr);
> + return __is_optimized((uprobe_opcode_t *)&insn, vaddr) ? 1 : 0;
> }
>
> static bool should_optimize(struct arch_uprobe *auprobe)
