| Message ID | 20180310204353.9584-1-kernel@kempniu.pl (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Darren Hart |
| Headers | show |
On Sat, Mar 10, 2018 at 09:43:53PM +0100, Micha?? K??pie?? wrote: > UNSUPPORTED_CMD was previously 0x80000000 (int), but commit 819cddae7cfa > ("platform/x86: fujitsu-laptop: Clean up constants") changed it into an > unsigned long due to BIT() being used to define it. As call_fext_func() > returns an int, 0x80000000 would get type promoted when compared to an > unsigned long, which on a 64-bit system would cause it to become > 0xffffffff80000000 due to sign extension. This causes one logical > condition in fujitsu-laptop to always be true and another one to always > be false on 64-bit systems. Fix this by reverting UNSUPPORTED_CMD back > to an int. > > This patch fixes the following smatch warnings: > > drivers/platform/x86/fujitsu-laptop.c:763 acpi_fujitsu_laptop_leds_register() warn: always true condition '(call_fext_func(device, ((1 << (12)) | (1 << (0))), 2, (1 << (16)), 0) != (1 << (31))) => (s32min-s32max != 2147483648)' > drivers/platform/x86/fujitsu-laptop.c:816 acpi_fujitsu_laptop_add() warn: impossible condition '(priv->flags_supported == (1 << (31))) => (0-2147483647,18446744071562067968-u64max == 2147483648)' > > Fixes: 819cddae7cfa ("platform/x86: fujitsu-laptop: Clean up constants") > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > Signed-off-by: Micha?? K??pie?? <kernel@kempniu.pl> > --- > This fixes a bug introduced by a commit queued for 4.17, so it needs to > be applied on top of for-next. > > drivers/platform/x86/fujitsu-laptop.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c > index 13bcdfea5349..6f4a55a53ced 100644 > --- a/drivers/platform/x86/fujitsu-laptop.c > +++ b/drivers/platform/x86/fujitsu-laptop.c > @@ -85,7 +85,7 @@ > #define FUNC_BACKLIGHT (BIT(12) | BIT(2)) > > /* FUNC interface - responses */ > -#define UNSUPPORTED_CMD BIT(31) > +#define UNSUPPORTED_CMD 0x80000000 > > /* FUNC interface - status flags */ > #define FLAG_RFKILL BIT(5) This looks like a sensible, succinct solution to the regression. Reviewed-by: Jonathan Woithe <jwoithe@just42.net> Regards jonathan
On Sun, Mar 11, 2018 at 02:40:56PM +1030, Jonathan Woithe wrote: > On Sat, Mar 10, 2018 at 09:43:53PM +0100, Micha?? K??pie?? wrote: > > UNSUPPORTED_CMD was previously 0x80000000 (int), but commit 819cddae7cfa > > ("platform/x86: fujitsu-laptop: Clean up constants") changed it into an > > unsigned long due to BIT() being used to define it. As call_fext_func() > > returns an int, 0x80000000 would get type promoted when compared to an > > unsigned long, which on a 64-bit system would cause it to become > > 0xffffffff80000000 due to sign extension. This causes one logical > > condition in fujitsu-laptop to always be true and another one to always > > be false on 64-bit systems. Fix this by reverting UNSUPPORTED_CMD back > > to an int. > > > > This patch fixes the following smatch warnings: > > > > drivers/platform/x86/fujitsu-laptop.c:763 acpi_fujitsu_laptop_leds_register() warn: always true condition '(call_fext_func(device, ((1 << (12)) | (1 << (0))), 2, (1 << (16)), 0) != (1 << (31))) => (s32min-s32max != 2147483648)' > > drivers/platform/x86/fujitsu-laptop.c:816 acpi_fujitsu_laptop_add() warn: impossible condition '(priv->flags_supported == (1 << (31))) => (0-2147483647,18446744071562067968-u64max == 2147483648)' > > > > Fixes: 819cddae7cfa ("platform/x86: fujitsu-laptop: Clean up constants") > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > Signed-off-by: Micha?? K??pie?? <kernel@kempniu.pl> Queued up, thank you.
diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c index 13bcdfea5349..6f4a55a53ced 100644 --- a/drivers/platform/x86/fujitsu-laptop.c +++ b/drivers/platform/x86/fujitsu-laptop.c @@ -85,7 +85,7 @@ #define FUNC_BACKLIGHT (BIT(12) | BIT(2)) /* FUNC interface - responses */ -#define UNSUPPORTED_CMD BIT(31) +#define UNSUPPORTED_CMD 0x80000000 /* FUNC interface - status flags */ #define FLAG_RFKILL BIT(5)
UNSUPPORTED_CMD was previously 0x80000000 (int), but commit 819cddae7cfa ("platform/x86: fujitsu-laptop: Clean up constants") changed it into an unsigned long due to BIT() being used to define it. As call_fext_func() returns an int, 0x80000000 would get type promoted when compared to an unsigned long, which on a 64-bit system would cause it to become 0xffffffff80000000 due to sign extension. This causes one logical condition in fujitsu-laptop to always be true and another one to always be false on 64-bit systems. Fix this by reverting UNSUPPORTED_CMD back to an int. This patch fixes the following smatch warnings: drivers/platform/x86/fujitsu-laptop.c:763 acpi_fujitsu_laptop_leds_register() warn: always true condition '(call_fext_func(device, ((1 << (12)) | (1 << (0))), 2, (1 << (16)), 0) != (1 << (31))) => (s32min-s32max != 2147483648)' drivers/platform/x86/fujitsu-laptop.c:816 acpi_fujitsu_laptop_add() warn: impossible condition '(priv->flags_supported == (1 << (31))) => (0-2147483647,18446744071562067968-u64max == 2147483648)' Fixes: 819cddae7cfa ("platform/x86: fujitsu-laptop: Clean up constants") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Michał Kępień <kernel@kempniu.pl> --- This fixes a bug introduced by a commit queued for 4.17, so it needs to be applied on top of for-next. drivers/platform/x86/fujitsu-laptop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)