The current control flow of IRQ number assignment to `irq` variable
allows a request of IRQ of unspecified value,
generating a warning under Clang compilation with omap1_defconfig on linux-next:
arch/arm/mach-omap1/pm.c:656:11: warning: variable 'irq' is used uninitialized whenever
'if' condition is false [-Wsometimes-uninitialized]
else if (cpu_is_omap16xx())
^~~~~~~~~~~~~~~~~
./arch/arm/mach-omap1/include/mach/soc.h:123:30: note: expanded from macro 'cpu_is_omap16xx'
^~~~~~~~~~~~~
arch/arm/mach-omap1/pm.c:658:18: note: uninitialized use occurs here
if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup",
^~~
arch/arm/mach-omap1/pm.c:656:7: note: remove the 'if' if its condition is always true
else if (cpu_is_omap16xx())
^~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-omap1/pm.c:611:9: note: initialize the variable 'irq' to silence this warning
int irq;
^
= 0
1 warning generated.
The patch provides a default value to the `irq` variable
along with a validity check.
Signed-off-by: Maciej Falkowski <[email protected]>
Link: https://github.com/ClangBuiltLinux/linux/issues/1324
---
arch/arm/mach-omap1/pm.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-omap1/pm.c b/arch/arm/mach-omap1/pm.c
index 2c1e2b32b9b3..a745d64d4699 100644
--- a/arch/arm/mach-omap1/pm.c
+++ b/arch/arm/mach-omap1/pm.c
@@ -655,9 +655,13 @@ static int __init omap_pm_init(void)
irq = INT_7XX_WAKE_UP_REQ;
else if (cpu_is_omap16xx())
irq = INT_1610_WAKE_UP_REQ;
- if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup",
- NULL))
- pr_err("Failed to request irq %d (peripheral wakeup)\n", irq);
+ else
+ irq = -1;
+
+ if (irq >= 0) {
+ if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup", NULL))
+ pr_err("Failed to request irq %d (peripheral wakeup)\n", irq);
+ }
/* Program new power ramp-up time
* (0 for most boards since we don't lower voltage when in deep sleep)
--
2.26.3
On Thu, Apr 1, 2021 at 9:12 AM Maciej Falkowski
<[email protected]> wrote:
>
> The current control flow of IRQ number assignment to `irq` variable
> allows a request of IRQ of unspecified value,
> generating a warning under Clang compilation with omap1_defconfig on linux-next:
>
> arch/arm/mach-omap1/pm.c:656:11: warning: variable 'irq' is used uninitialized whenever
> 'if' condition is false [-Wsometimes-uninitialized]
> else if (cpu_is_omap16xx())
> ^~~~~~~~~~~~~~~~~
> ./arch/arm/mach-omap1/include/mach/soc.h:123:30: note: expanded from macro 'cpu_is_omap16xx'
> ^~~~~~~~~~~~~
> arch/arm/mach-omap1/pm.c:658:18: note: uninitialized use occurs here
> if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup",
> ^~~
> arch/arm/mach-omap1/pm.c:656:7: note: remove the 'if' if its condition is always true
> else if (cpu_is_omap16xx())
> ^~~~~~~~~~~~~~~~~~~~~~
> arch/arm/mach-omap1/pm.c:611:9: note: initialize the variable 'irq' to silence this warning
> int irq;
> ^
> = 0
> 1 warning generated.
Ooh, yeah if cpu_is_omap15xx() then irq is unused uninitialized; I
don't see any INT_1610_WAKE_UP_REQ-equlivalent for
INT_15XX_WAKE_UP_REQ.
Ok, LGTM.
Reviewed-by: Nick Desaulniers <[email protected]>
I agree with Nathan on the Fixes tag.
>
> The patch provides a default value to the `irq` variable
> along with a validity check.
>
> Signed-off-by: Maciej Falkowski <[email protected]>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1324
> ---
> arch/arm/mach-omap1/pm.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-omap1/pm.c b/arch/arm/mach-omap1/pm.c
> index 2c1e2b32b9b3..a745d64d4699 100644
> --- a/arch/arm/mach-omap1/pm.c
> +++ b/arch/arm/mach-omap1/pm.c
> @@ -655,9 +655,13 @@ static int __init omap_pm_init(void)
> irq = INT_7XX_WAKE_UP_REQ;
> else if (cpu_is_omap16xx())
> irq = INT_1610_WAKE_UP_REQ;
> - if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup",
> - NULL))
> - pr_err("Failed to request irq %d (peripheral wakeup)\n", irq);
> + else
> + irq = -1;
> +
> + if (irq >= 0) {
> + if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup", NULL))
> + pr_err("Failed to request irq %d (peripheral wakeup)\n", irq);
> + }
>
> /* Program new power ramp-up time
> * (0 for most boards since we don't lower voltage when in deep sleep)
> --
--
Thanks,
~Nick Desaulniers
* Maciej Falkowski <[email protected]> [210401 19:13]:
> The current control flow of IRQ number assignment to `irq` variable
> allows a request of IRQ of unspecified value,
> generating a warning under Clang compilation with omap1_defconfig on linux-next:
>
> arch/arm/mach-omap1/pm.c:656:11: warning: variable 'irq' is used uninitialized whenever
> 'if' condition is false [-Wsometimes-uninitialized]
> else if (cpu_is_omap16xx())
> ^~~~~~~~~~~~~~~~~
> ./arch/arm/mach-omap1/include/mach/soc.h:123:30: note: expanded from macro 'cpu_is_omap16xx'
> ^~~~~~~~~~~~~
> arch/arm/mach-omap1/pm.c:658:18: note: uninitialized use occurs here
> if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup",
> ^~~
> arch/arm/mach-omap1/pm.c:656:7: note: remove the 'if' if its condition is always true
> else if (cpu_is_omap16xx())
> ^~~~~~~~~~~~~~~~~~~~~~
> arch/arm/mach-omap1/pm.c:611:9: note: initialize the variable 'irq' to silence this warning
> int irq;
> ^
> = 0
Thanks applying into fixes.
Tony