In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9
option") the following piece of code was added:
smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
Since GCC 8 this trigger the following warning about incompatible
function types:
arch/powerpc/kernel/hw_breakpoint.c:408:21: error: cast between incompatible function types from 'int (*)(struct arch_hw_breakpoint *)' to 'void (*)(void *)' [-Werror=cast-function-type]
Cast the function to an intermediate (void*) to make the compiler loose
knowledge about actual type.
Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option")
Cc: Michael Neuling <[email protected]>
Signed-off-by: Mathieu Malaterre <[email protected]>
---
arch/powerpc/kernel/hw_breakpoint.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index f70fb89dbf60..baeb4c58de3b 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -405,7 +405,8 @@ static ssize_t dawr_write_file_bool(struct file *file,
/* If we are clearing, make sure all CPUs have the DAWR cleared */
if (!dawr_force_enable)
- smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
+ smp_call_function((smp_call_func_t)(void *)set_dawr,
+ &null_brk, 0);
return rc;
}
--
2.20.1
On Wed, May 15, 2019 at 02:09:42PM +0200, Mathieu Malaterre wrote:
> In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9
> option") the following piece of code was added:
>
> smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
>
> Since GCC 8 this trigger the following warning about incompatible
> function types:
And the warning is there for a reason, and should not be hidden
behind a cast. This should instead be fixed by something like this:
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index da307dd93ee3..a26b67a1be83 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -384,6 +384,12 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
bool dawr_force_enable;
EXPORT_SYMBOL_GPL(dawr_force_enable);
+
+static void set_dawr_cb(void *info)
+{
+ set_dawr(info);
+}
+
static ssize_t dawr_write_file_bool(struct file *file,
const char __user *user_buf,
size_t count, loff_t *ppos)
@@ -403,7 +409,7 @@ static ssize_t dawr_write_file_bool(struct file *file,
/* If we are clearing, make sure all CPUs have the DAWR cleared */
if (!dawr_force_enable)
- smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
+ smp_call_function(set_dawr_cb, &null_brk, 0);
return rc;
}
Hi Christoph,
On Wed, May 15, 2019 at 3:14 PM Christoph Hellwig <[email protected]> wrote:
>
> On Wed, May 15, 2019 at 02:09:42PM +0200, Mathieu Malaterre wrote:
> > In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9
> > option") the following piece of code was added:
> >
> > smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
> >
> > Since GCC 8 this trigger the following warning about incompatible
> > function types:
>
> And the warning is there for a reason, and should not be hidden
> behind a cast. This should instead be fixed by something like this:
<meme: I have no idea what I am doing>
OK, thanks for the quick feedback, will send a v2 asap.
> diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
> index da307dd93ee3..a26b67a1be83 100644
> --- a/arch/powerpc/kernel/hw_breakpoint.c
> +++ b/arch/powerpc/kernel/hw_breakpoint.c
> @@ -384,6 +384,12 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
> bool dawr_force_enable;
> EXPORT_SYMBOL_GPL(dawr_force_enable);
>
> +
> +static void set_dawr_cb(void *info)
> +{
> + set_dawr(info);
> +}
> +
> static ssize_t dawr_write_file_bool(struct file *file,
> const char __user *user_buf,
> size_t count, loff_t *ppos)
> @@ -403,7 +409,7 @@ static ssize_t dawr_write_file_bool(struct file *file,
>
> /* If we are clearing, make sure all CPUs have the DAWR cleared */
> if (!dawr_force_enable)
> - smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
> + smp_call_function(set_dawr_cb, &null_brk, 0);
>
> return rc;
> }
In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9
option") the following piece of code was added:
smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
Since GCC 8 this triggers the following warning about incompatible
function types:
arch/powerpc/kernel/hw_breakpoint.c:408:21: error: cast between incompatible function types from 'int (*)(struct arch_hw_breakpoint *)' to 'void (*)(void *)' [-Werror=cast-function-type]
Since the warning is there for a reason, and should not be hidden behind
a cast, provide an intermediate callback function to avoid the warning.
Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option")
Suggested-by: Christoph Hellwig <[email protected]>
Cc: Michael Neuling <[email protected]>
Signed-off-by: Mathieu Malaterre <[email protected]>
---
v2: do not hide warning using a hack
arch/powerpc/kernel/hw_breakpoint.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index f70fb89dbf60..969092d84a2f 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -386,6 +386,11 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
bool dawr_force_enable;
EXPORT_SYMBOL_GPL(dawr_force_enable);
+static void set_dawr_cb(void *info)
+{
+ set_dawr(info);
+}
+
static ssize_t dawr_write_file_bool(struct file *file,
const char __user *user_buf,
size_t count, loff_t *ppos)
@@ -405,7 +410,7 @@ static ssize_t dawr_write_file_bool(struct file *file,
/* If we are clearing, make sure all CPUs have the DAWR cleared */
if (!dawr_force_enable)
- smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
+ smp_call_function(set_dawr_cb, &null_brk, 0);
return rc;
}
--
2.20.1