On Tue, 25 Feb 2025 10:10:29 +0100, Jani Nikula wrote: > > On Mon, 24 Feb 2025, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > On Mon, Feb 24, 2025 at 03:14:33PM +0200, Jani Nikula wrote: > >> On Wed, 19 Feb 2025, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > >> > The "id" variable is an enum and in this context it's treated as an > >> > unsigned int so the error handling can never trigger. The > >> > ->get_client_id() functions do not currently return any errors but > >> > I imagine that if they did, then the intention was to return > >> > VGA_SWITCHEROO_UNKNOWN_ID on error. Let's check for both negatives > >> > and UNKNOWN_ID so we'll catch it either way. > >> > > >> > Reported-by: Su Hui <suhui@xxxxxxxxxxxx> > >> > Closes: https://lore.kernel.org/all/20231026021056.850680-1-suhui@xxxxxxxxxxxx/ > >> > Fixes: 4aaf448fa975 ("vga_switcheroo: set audio client id according to bound GPU id") > >> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > >> > --- > >> > drivers/gpu/vga/vga_switcheroo.c | 2 +- > >> > 1 file changed, 1 insertion(+), 1 deletion(-) > >> > > >> > diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c > >> > index 18f2c92beff8..216fb208eb31 100644 > >> > --- a/drivers/gpu/vga/vga_switcheroo.c > >> > +++ b/drivers/gpu/vga/vga_switcheroo.c > >> > @@ -375,7 +375,7 @@ int vga_switcheroo_register_audio_client(struct pci_dev *pdev, > >> > mutex_lock(&vgasr_mutex); > >> > if (vgasr_priv.active) { > >> > id = vgasr_priv.handler->get_client_id(vga_dev); > >> > - if (id < 0) { > >> > + if ((int)id < 0 || id == VGA_SWITCHEROO_UNKNOWN_ID) { > >> > >> Maybe we want to do something else here... see [1]. > >> > >> BR, > >> Jani. > >> > >> > >> [1] https://lore.kernel.org/r/CAHk-=wgg2A_iHNwf_JDjYJF=XHnKVGOjGp50FzVWniA2Z010bw@xxxxxxxxxxxxxx > >> > > > > I feel like my patch is good enough... I guess the concern here is that > > GCC could change enums to something else. I don't think that's likely as > > it would break a lot of code. The other option, which is a good option, > > is to change the function signature for vgasr_priv.handler->get_client_id() > > so that we do: > > > > ret = vgasr_priv.handler->get_client_id(vga_dev, &id); > > if (ret) > > return; > > > > That's better code, honestly. But I can't find motivation enough to do > > the work. > > The more I look at this, the more bonkers 4aaf448fa975 feels. > > Anyway, I don't think ->get_client_id() hooks should return negative > error codes, and indeed none of them do. None of them return > VGA_SWITCHEROO_UNKNOWN_ID either, but that would be a valid return. > > I suggest only checking for id == VGA_SWITCHEROO_UNKNOWN_ID. And doing > that in all the places that have that check, there are two more, but > they assign the return value to an int. So the int ret should be changed > to enum vga_switcheroo_unknown_id id I think. +1, this sounds like the cleanest way. > Any chance of finding enough motivation to do that? ;) For whom? ;) thanks, Takashi
