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* [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
@ 2021-04-14 14:10 kernel test robot
  2021-04-14 14:33   ` Marco Elver
  0 siblings, 1 reply; 9+ messages in thread
From: kernel test robot @ 2021-04-14 14:10 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 13108 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
head:   0da503cd07380952599b67ded6efe030d78ea42d
commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
config: arc-randconfig-s032-20210414 (attached as .config)
compiler: arc-elf-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-280-g2cd6d34e-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?id=c7d4112e9f0e69edd649665836ce72008b95ab9f
        git remote add peterz-queue https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git
        git fetch --no-tags peterz-queue perf/core
        git checkout c7d4112e9f0e69edd649665836ce72008b95ab9f
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=arc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
   kernel/events/core.c:584:26: sparse: sparse: function 'perf_pmu_name' with external linkage has definition
   kernel/events/core.c:1467:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:1467:15: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:1467:15: sparse:    struct perf_event_context *
   kernel/events/core.c:1480:28: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:1480:28: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:1480:28: sparse:    struct perf_event_context *
   kernel/events/core.c:3430:18: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:3430:18: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:3430:18: sparse:    struct perf_event_context *
   kernel/events/core.c:3431:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:3431:23: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:3431:23: sparse:    struct perf_event_context *
   kernel/events/core.c:3479:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:3479:25: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:3479:25: sparse:    struct perf_event_context *
   kernel/events/core.c:3480:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:3480:25: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:3480:25: sparse:    struct perf_event_context *
   kernel/events/core.c:4673:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:4673:25: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:4673:25: sparse:    struct perf_event_context *
   kernel/events/core.c:5935:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5935:9: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5935:9: sparse:    struct perf_buffer *
   kernel/events/core.c:5411:24: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __poll_t [usertype] events @@     got int @@
   kernel/events/core.c:5641:22: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5641:22: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5641:22: sparse:    struct perf_buffer *
   kernel/events/core.c:5777:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5777:14: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5777:14: sparse:    struct perf_buffer *
   kernel/events/core.c:5810:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5810:14: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5810:14: sparse:    struct perf_buffer *
   kernel/events/core.c:5867:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5867:14: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5867:14: sparse:    struct perf_buffer *
   kernel/events/core.c:5953:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5953:14: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5953:14: sparse:    struct perf_buffer *
   kernel/events/core.c:5966:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:5966:14: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:5966:14: sparse:    struct perf_buffer *
>> kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void [noderef] __user *[addressable] [assigned] _addr @@     got void * @@
   kernel/events/core.c:6418:22: sparse:     expected void [noderef] __user *[addressable] [assigned] _addr
   kernel/events/core.c:6418:22: sparse:     got void *
   kernel/events/core.c:6682:6: sparse: sparse: symbol 'perf_pmu_snapshot_aux' was not declared. Should it be static?
   kernel/events/core.c:7601:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:7601:23: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:7601:23: sparse:    struct perf_event_context *
   kernel/events/core.c:7653:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:7653:23: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:7653:23: sparse:    struct perf_event_context *
   kernel/events/core.c:7692:13: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:7692:13: sparse:    struct perf_buffer [noderef] __rcu *
   kernel/events/core.c:7692:13: sparse:    struct perf_buffer *
   kernel/events/core.c:7797:61: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected struct task_struct *p @@     got struct task_struct [noderef] __rcu *real_parent @@
   kernel/events/core.c:7797:61: sparse:     expected struct task_struct *p
   kernel/events/core.c:7797:61: sparse:     got struct task_struct [noderef] __rcu *real_parent
   kernel/events/core.c:7799:61: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected struct task_struct *p @@     got struct task_struct [noderef] __rcu *real_parent @@
   kernel/events/core.c:7799:61: sparse:     expected struct task_struct *p
   kernel/events/core.c:7799:61: sparse:     got struct task_struct [noderef] __rcu *real_parent
   kernel/events/core.c:8504:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:8504:23: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:8504:23: sparse:    struct perf_event_context *
   kernel/events/core.c:9469:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9469:9: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9469:9: sparse:    struct swevent_hlist *
   kernel/events/core.c:9508:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9508:17: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9508:17: sparse:    struct swevent_hlist *
   kernel/events/core.c:9689:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9689:23: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:9689:23: sparse:    struct perf_event_context *
   kernel/events/core.c:10874:1: sparse: sparse: symbol 'dev_attr_nr_addr_filters' was not declared. Should it be static?
   kernel/events/core.c:12630:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:12630:9: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:12630:9: sparse:    struct perf_event_context *
   kernel/events/core.c:12740:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:12740:17: sparse:    struct perf_event_context [noderef] __rcu *
   kernel/events/core.c:12740:17: sparse:    struct perf_event_context *
   kernel/events/core.c:13170:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:13170:17: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:13170:17: sparse:    struct swevent_hlist *
   kernel/events/core.c:166:9: sparse: sparse: context imbalance in 'perf_ctx_lock' - wrong count at exit
   kernel/events/core.c:174:17: sparse: sparse: context imbalance in 'perf_ctx_unlock' - unexpected unlock
   kernel/events/core.c: note: in included file (through include/linux/rculist.h, include/linux/dcache.h, include/linux/fs.h):
   include/linux/rcupdate.h:706:9: sparse: sparse: context imbalance in 'perf_lock_task_context' - different lock contexts for basic block
   kernel/events/core.c:1514:17: sparse: sparse: context imbalance in 'perf_pin_task_context' - unexpected unlock
   kernel/events/core.c:2827:9: sparse: sparse: context imbalance in '__perf_install_in_context' - wrong count at exit
   kernel/events/core.c:4645:17: sparse: sparse: context imbalance in 'find_get_context' - unexpected unlock
   kernel/events/core.c: note: in included file:
   kernel/events/internal.h:197:46: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void const [noderef] __user *from @@     got void const *src @@
   kernel/events/core.c:9318:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9318:17: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9318:17: sparse:    struct swevent_hlist *
   kernel/events/core.c:9338:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9338:17: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9338:17: sparse:    struct swevent_hlist *
   kernel/events/core.c:9458:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9458:16: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9458:16: sparse:    struct swevent_hlist *
   kernel/events/core.c:9458:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9458:16: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9458:16: sparse:    struct swevent_hlist *
   kernel/events/core.c:9458:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/events/core.c:9458:16: sparse:    struct swevent_hlist [noderef] __rcu *
   kernel/events/core.c:9458:16: sparse:    struct swevent_hlist *

vim +6418 kernel/events/core.c

  6394	
  6395	static void perf_sigtrap(struct perf_event *event)
  6396	{
  6397		struct kernel_siginfo info;
  6398	
  6399		/*
  6400		 * We'd expect this to only occur if the irq_work is delayed and either
  6401		 * ctx->task or current has changed in the meantime. This can be the
  6402		 * case on architectures that do not implement arch_irq_work_raise().
  6403		 */
  6404		if (WARN_ON_ONCE(event->ctx->task != current))
  6405			return;
  6406	
  6407		/*
  6408		 * perf_pending_event() can race with the task exiting.
  6409		 */
  6410		if (current->flags & PF_EXITING)
  6411			return;
  6412	
  6413		clear_siginfo(&info);
  6414		info.si_signo = SIGTRAP;
  6415		info.si_code = TRAP_PERF;
  6416		info.si_errno = event->attr.type;
  6417		info.si_perf = event->attr.sig_data;
> 6418		info.si_addr = (void *)event->sig_addr;
  6419		force_sig_info(&info);
  6420	}
  6421	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
  2021-04-14 14:10 [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces) kernel test robot
@ 2021-04-14 14:33   ` Marco Elver
  0 siblings, 0 replies; 9+ messages in thread
From: Marco Elver @ 2021-04-14 14:33 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: kbuild-all, kernel test robot, linux-kernel

On Wed, Apr 14, 2021 at 10:10PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
> head:   0da503cd07380952599b67ded6efe030d78ea42d
> commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
[...]
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
[...]
>   6416		info.si_errno = event->attr.type;
>   6417		info.si_perf = event->attr.sig_data;
> > 6418		info.si_addr = (void *)event->sig_addr;
>   6419		force_sig_info(&info);

I think it wants the below (feel free to squash into "perf: Add support
for SIGTRAP on perf events").

Thanks,
-- Marco

------ >8 ------

From: Marco Elver <elver@google.com>
Date: Wed, 14 Apr 2021 16:26:26 +0200
Subject: [PATCH] perf: Fix cast to void __user pointer

sparse let us know that si_addr is 'void __user *', therefore add the
missing __user attribute to the cast.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marco Elver <elver@google.com>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1d2077389c0c..2677438ed668 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6414,7 +6414,7 @@ static void perf_sigtrap(struct perf_event *event)
 	info.si_code = TRAP_PERF;
 	info.si_errno = event->attr.type;
 	info.si_perf = event->attr.sig_data;
-	info.si_addr = (void *)event->sig_addr;
+	info.si_addr = (void __user *)event->sig_addr;
 	force_sig_info(&info);
 }
 
-- 
2.31.1.295.g9ea45b61b8-goog


^ permalink raw reply related	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
@ 2021-04-14 14:33   ` Marco Elver
  0 siblings, 0 replies; 9+ messages in thread
From: Marco Elver @ 2021-04-14 14:33 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 1686 bytes --]

On Wed, Apr 14, 2021 at 10:10PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
> head:   0da503cd07380952599b67ded6efe030d78ea42d
> commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
[...]
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
[...]
>   6416		info.si_errno = event->attr.type;
>   6417		info.si_perf = event->attr.sig_data;
> > 6418		info.si_addr = (void *)event->sig_addr;
>   6419		force_sig_info(&info);

I think it wants the below (feel free to squash into "perf: Add support
for SIGTRAP on perf events").

Thanks,
-- Marco

------ >8 ------

From: Marco Elver <elver@google.com>
Date: Wed, 14 Apr 2021 16:26:26 +0200
Subject: [PATCH] perf: Fix cast to void __user pointer

sparse let us know that si_addr is 'void __user *', therefore add the
missing __user attribute to the cast.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marco Elver <elver@google.com>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1d2077389c0c..2677438ed668 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6414,7 +6414,7 @@ static void perf_sigtrap(struct perf_event *event)
 	info.si_code = TRAP_PERF;
 	info.si_errno = event->attr.type;
 	info.si_perf = event->attr.sig_data;
-	info.si_addr = (void *)event->sig_addr;
+	info.si_addr = (void __user *)event->sig_addr;
 	force_sig_info(&info);
 }
 
-- 
2.31.1.295.g9ea45b61b8-goog

^ permalink raw reply related	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
  2021-04-14 14:33   ` Marco Elver
@ 2021-04-15  8:48     ` Peter Zijlstra
  -1 siblings, 0 replies; 9+ messages in thread
From: Peter Zijlstra @ 2021-04-15  8:48 UTC (permalink / raw)
  To: Marco Elver; +Cc: kbuild-all, kernel test robot, linux-kernel

On Wed, Apr 14, 2021 at 04:33:22PM +0200, Marco Elver wrote:
> On Wed, Apr 14, 2021 at 10:10PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
> > head:   0da503cd07380952599b67ded6efe030d78ea42d
> > commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
> [...]
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> [...]
> >   6416		info.si_errno = event->attr.type;
> >   6417		info.si_perf = event->attr.sig_data;
> > > 6418		info.si_addr = (void *)event->sig_addr;
> >   6419		force_sig_info(&info);
> 
> I think it wants the below (feel free to squash into "perf: Add support
> for SIGTRAP on perf events").
> 
> Thanks,
> -- Marco
> 
> ------ >8 ------
> 
> From: Marco Elver <elver@google.com>
> Date: Wed, 14 Apr 2021 16:26:26 +0200
> Subject: [PATCH] perf: Fix cast to void __user pointer
> 
> sparse let us know that si_addr is 'void __user *', therefore add the
> missing __user attribute to the cast.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Marco Elver <elver@google.com>
> ---
>  kernel/events/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 1d2077389c0c..2677438ed668 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6414,7 +6414,7 @@ static void perf_sigtrap(struct perf_event *event)
>  	info.si_code = TRAP_PERF;
>  	info.si_errno = event->attr.type;
>  	info.si_perf = event->attr.sig_data;
> -	info.si_addr = (void *)event->sig_addr;
> +	info.si_addr = (void __user *)event->sig_addr;
>  	force_sig_info(&info);
>  }

Now the silly robot complains about:

CC      kernel/events/core.o
../kernel/events/core.c: In function ‘perf_sigtrap’:
../kernel/events/core.c:6418:17: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
6418 |  info.si_addr = (void __user *)event->sig_addr;

for all 32bit builds (because sig_addr is u64 and the pointer cast
truncates bits).

This had me look a little harder at sig_addr and I figured it should be
next to the pending fields for cache locality.

I've ended up with the below delta, does that work for you?

---

--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -735,6 +735,7 @@ struct perf_event {
 	int				pending_wakeup;
 	int				pending_kill;
 	int				pending_disable;
+	unsigned long			pending_addr;	/* SIGTRAP */
 	struct irq_work			pending;
 
 	atomic_t			event_limit;
@@ -778,9 +779,6 @@ struct perf_event {
 	void *security;
 #endif
 	struct list_head		sb_list;
-
-	/* Address associated with event, which can be passed to siginfo_t. */
-	u64				sig_addr;
 #endif /* CONFIG_PERF_EVENTS */
 };
 
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6415,7 +6415,7 @@ static void perf_sigtrap(struct perf_eve
 	info.si_code = TRAP_PERF;
 	info.si_errno = event->attr.type;
 	info.si_perf = event->attr.sig_data;
-	info.si_addr = (void __user *)event->sig_addr;
+	info.si_addr = (void __user *)event->pending_addr;
 	force_sig_info(&info);
 }
 
@@ -9137,7 +9137,7 @@ static int __perf_event_overflow(struct
 	if (events && atomic_dec_and_test(&event->event_limit)) {
 		ret = 1;
 		event->pending_kill = POLL_HUP;
-		event->sig_addr = data->addr;
+		event->pending_addr = data->addr;
 
 		perf_event_disable_inatomic(event);
 	}

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
@ 2021-04-15  8:48     ` Peter Zijlstra
  0 siblings, 0 replies; 9+ messages in thread
From: Peter Zijlstra @ 2021-04-15  8:48 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 3571 bytes --]

On Wed, Apr 14, 2021 at 04:33:22PM +0200, Marco Elver wrote:
> On Wed, Apr 14, 2021 at 10:10PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
> > head:   0da503cd07380952599b67ded6efe030d78ea42d
> > commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
> [...]
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> [...]
> >   6416		info.si_errno = event->attr.type;
> >   6417		info.si_perf = event->attr.sig_data;
> > > 6418		info.si_addr = (void *)event->sig_addr;
> >   6419		force_sig_info(&info);
> 
> I think it wants the below (feel free to squash into "perf: Add support
> for SIGTRAP on perf events").
> 
> Thanks,
> -- Marco
> 
> ------ >8 ------
> 
> From: Marco Elver <elver@google.com>
> Date: Wed, 14 Apr 2021 16:26:26 +0200
> Subject: [PATCH] perf: Fix cast to void __user pointer
> 
> sparse let us know that si_addr is 'void __user *', therefore add the
> missing __user attribute to the cast.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Marco Elver <elver@google.com>
> ---
>  kernel/events/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 1d2077389c0c..2677438ed668 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6414,7 +6414,7 @@ static void perf_sigtrap(struct perf_event *event)
>  	info.si_code = TRAP_PERF;
>  	info.si_errno = event->attr.type;
>  	info.si_perf = event->attr.sig_data;
> -	info.si_addr = (void *)event->sig_addr;
> +	info.si_addr = (void __user *)event->sig_addr;
>  	force_sig_info(&info);
>  }

Now the silly robot complains about:

CC      kernel/events/core.o
../kernel/events/core.c: In function ‘perf_sigtrap’:
../kernel/events/core.c:6418:17: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
6418 |  info.si_addr = (void __user *)event->sig_addr;

for all 32bit builds (because sig_addr is u64 and the pointer cast
truncates bits).

This had me look a little harder at sig_addr and I figured it should be
next to the pending fields for cache locality.

I've ended up with the below delta, does that work for you?

---

--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -735,6 +735,7 @@ struct perf_event {
 	int				pending_wakeup;
 	int				pending_kill;
 	int				pending_disable;
+	unsigned long			pending_addr;	/* SIGTRAP */
 	struct irq_work			pending;
 
 	atomic_t			event_limit;
@@ -778,9 +779,6 @@ struct perf_event {
 	void *security;
 #endif
 	struct list_head		sb_list;
-
-	/* Address associated with event, which can be passed to siginfo_t. */
-	u64				sig_addr;
 #endif /* CONFIG_PERF_EVENTS */
 };
 
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6415,7 +6415,7 @@ static void perf_sigtrap(struct perf_eve
 	info.si_code = TRAP_PERF;
 	info.si_errno = event->attr.type;
 	info.si_perf = event->attr.sig_data;
-	info.si_addr = (void __user *)event->sig_addr;
+	info.si_addr = (void __user *)event->pending_addr;
 	force_sig_info(&info);
 }
 
@@ -9137,7 +9137,7 @@ static int __perf_event_overflow(struct
 	if (events && atomic_dec_and_test(&event->event_limit)) {
 		ret = 1;
 		event->pending_kill = POLL_HUP;
-		event->sig_addr = data->addr;
+		event->pending_addr = data->addr;
 
 		perf_event_disable_inatomic(event);
 	}

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
  2021-04-15  8:48     ` Peter Zijlstra
@ 2021-04-15  9:03       ` Marco Elver
  -1 siblings, 0 replies; 9+ messages in thread
From: Marco Elver @ 2021-04-15  9:03 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: kbuild-all, kernel test robot, linux-kernel

On Thu, Apr 15, 2021 at 10:48AM +0200, Peter Zijlstra wrote:
> On Wed, Apr 14, 2021 at 04:33:22PM +0200, Marco Elver wrote:
> > On Wed, Apr 14, 2021 at 10:10PM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
> > > head:   0da503cd07380952599b67ded6efe030d78ea42d
> > > commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
> > [...]
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > [...]
> > >   6416		info.si_errno = event->attr.type;
> > >   6417		info.si_perf = event->attr.sig_data;
> > > > 6418		info.si_addr = (void *)event->sig_addr;
> > >   6419		force_sig_info(&info);
> > 
> > I think it wants the below (feel free to squash into "perf: Add support
> > for SIGTRAP on perf events").
> > 
> > Thanks,
> > -- Marco
> > 
[...]
> 
> Now the silly robot complains about:
> 
> CC      kernel/events/core.o
> ../kernel/events/core.c: In function ‘perf_sigtrap’:
> ../kernel/events/core.c:6418:17: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> 6418 |  info.si_addr = (void __user *)event->sig_addr;
> 
> for all 32bit builds (because sig_addr is u64 and the pointer cast
> truncates bits).
> 
> This had me look a little harder at sig_addr and I figured it should be
> next to the pending fields for cache locality.
> 
> I've ended up with the below delta, does that work for you?

Thanks, that works for me. Do note that I explicitly chose u64 for
sig_addr/pending_addr because data->addr is u64. There might be a new
warning about the u64 to unsigned long assignment on 32 bit arches.

Perhaps it needs something ugly like this:

	info.si_addr = (void __user *)(unsigned long)event->pending_addr;

if pending_addr wants to be u64. Or just

	event->pending_addr = (unsigned long)data->addr;

if data->addr being u64 on 32 bit arches is simply overkill.

Thanks,
-- Marco

> ---
> 
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -735,6 +735,7 @@ struct perf_event {
>  	int				pending_wakeup;
>  	int				pending_kill;
>  	int				pending_disable;
> +	unsigned long			pending_addr;	/* SIGTRAP */
>  	struct irq_work			pending;
>  
>  	atomic_t			event_limit;
> @@ -778,9 +779,6 @@ struct perf_event {
>  	void *security;
>  #endif
>  	struct list_head		sb_list;
> -
> -	/* Address associated with event, which can be passed to siginfo_t. */
> -	u64				sig_addr;
>  #endif /* CONFIG_PERF_EVENTS */
>  };
>  
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6415,7 +6415,7 @@ static void perf_sigtrap(struct perf_eve
>  	info.si_code = TRAP_PERF;
>  	info.si_errno = event->attr.type;
>  	info.si_perf = event->attr.sig_data;
> -	info.si_addr = (void __user *)event->sig_addr;
> +	info.si_addr = (void __user *)event->pending_addr;
>  	force_sig_info(&info);
>  }
>  
> @@ -9137,7 +9137,7 @@ static int __perf_event_overflow(struct
>  	if (events && atomic_dec_and_test(&event->event_limit)) {
>  		ret = 1;
>  		event->pending_kill = POLL_HUP;
> -		event->sig_addr = data->addr;
> +		event->pending_addr = data->addr;
>  
>  		perf_event_disable_inatomic(event);
>  	}

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
@ 2021-04-15  9:03       ` Marco Elver
  0 siblings, 0 replies; 9+ messages in thread
From: Marco Elver @ 2021-04-15  9:03 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 3343 bytes --]

On Thu, Apr 15, 2021 at 10:48AM +0200, Peter Zijlstra wrote:
> On Wed, Apr 14, 2021 at 04:33:22PM +0200, Marco Elver wrote:
> > On Wed, Apr 14, 2021 at 10:10PM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
> > > head:   0da503cd07380952599b67ded6efe030d78ea42d
> > > commit: c7d4112e9f0e69edd649665836ce72008b95ab9f [18/22] perf: Add support for SIGTRAP on perf events
> > [...]
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > [...]
> > >   6416		info.si_errno = event->attr.type;
> > >   6417		info.si_perf = event->attr.sig_data;
> > > > 6418		info.si_addr = (void *)event->sig_addr;
> > >   6419		force_sig_info(&info);
> > 
> > I think it wants the below (feel free to squash into "perf: Add support
> > for SIGTRAP on perf events").
> > 
> > Thanks,
> > -- Marco
> > 
[...]
> 
> Now the silly robot complains about:
> 
> CC      kernel/events/core.o
> ../kernel/events/core.c: In function ‘perf_sigtrap’:
> ../kernel/events/core.c:6418:17: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> 6418 |  info.si_addr = (void __user *)event->sig_addr;
> 
> for all 32bit builds (because sig_addr is u64 and the pointer cast
> truncates bits).
> 
> This had me look a little harder at sig_addr and I figured it should be
> next to the pending fields for cache locality.
> 
> I've ended up with the below delta, does that work for you?

Thanks, that works for me. Do note that I explicitly chose u64 for
sig_addr/pending_addr because data->addr is u64. There might be a new
warning about the u64 to unsigned long assignment on 32 bit arches.

Perhaps it needs something ugly like this:

	info.si_addr = (void __user *)(unsigned long)event->pending_addr;

if pending_addr wants to be u64. Or just

	event->pending_addr = (unsigned long)data->addr;

if data->addr being u64 on 32 bit arches is simply overkill.

Thanks,
-- Marco

> ---
> 
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -735,6 +735,7 @@ struct perf_event {
>  	int				pending_wakeup;
>  	int				pending_kill;
>  	int				pending_disable;
> +	unsigned long			pending_addr;	/* SIGTRAP */
>  	struct irq_work			pending;
>  
>  	atomic_t			event_limit;
> @@ -778,9 +779,6 @@ struct perf_event {
>  	void *security;
>  #endif
>  	struct list_head		sb_list;
> -
> -	/* Address associated with event, which can be passed to siginfo_t. */
> -	u64				sig_addr;
>  #endif /* CONFIG_PERF_EVENTS */
>  };
>  
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6415,7 +6415,7 @@ static void perf_sigtrap(struct perf_eve
>  	info.si_code = TRAP_PERF;
>  	info.si_errno = event->attr.type;
>  	info.si_perf = event->attr.sig_data;
> -	info.si_addr = (void __user *)event->sig_addr;
> +	info.si_addr = (void __user *)event->pending_addr;
>  	force_sig_info(&info);
>  }
>  
> @@ -9137,7 +9137,7 @@ static int __perf_event_overflow(struct
>  	if (events && atomic_dec_and_test(&event->event_limit)) {
>  		ret = 1;
>  		event->pending_kill = POLL_HUP;
> -		event->sig_addr = data->addr;
> +		event->pending_addr = data->addr;
>  
>  		perf_event_disable_inatomic(event);
>  	}

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
  2021-04-15  9:03       ` Marco Elver
@ 2021-04-15  9:11         ` Peter Zijlstra
  -1 siblings, 0 replies; 9+ messages in thread
From: Peter Zijlstra @ 2021-04-15  9:11 UTC (permalink / raw)
  To: Marco Elver; +Cc: kbuild-all, kernel test robot, linux-kernel

On Thu, Apr 15, 2021 at 11:03:09AM +0200, Marco Elver wrote:
> On Thu, Apr 15, 2021 at 10:48AM +0200, Peter Zijlstra wrote:

> > I've ended up with the below delta, does that work for you?
> 
> Thanks, that works for me. Do note that I explicitly chose u64 for
> sig_addr/pending_addr because data->addr is u64. There might be a new
> warning about the u64 to unsigned long assignment on 32 bit arches.

My local i386-defconfig build seemed happy now. Mostly I think you're
allowed to silently truncate between base integer types. We'll see..
maybe some other compiler.

> Perhaps it needs something ugly like this:
> 
> 	info.si_addr = (void __user *)(unsigned long)event->pending_addr;
> 
> if pending_addr wants to be u64. Or just
> 
> 	event->pending_addr = (unsigned long)data->addr;
> 
> if data->addr being u64 on 32 bit arches is simply overkill.

Yeah it is. It's u64 for data layout purposes, the perf buffer works in
u64 chunks.

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces)
@ 2021-04-15  9:11         ` Peter Zijlstra
  0 siblings, 0 replies; 9+ messages in thread
From: Peter Zijlstra @ 2021-04-15  9:11 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 963 bytes --]

On Thu, Apr 15, 2021 at 11:03:09AM +0200, Marco Elver wrote:
> On Thu, Apr 15, 2021 at 10:48AM +0200, Peter Zijlstra wrote:

> > I've ended up with the below delta, does that work for you?
> 
> Thanks, that works for me. Do note that I explicitly chose u64 for
> sig_addr/pending_addr because data->addr is u64. There might be a new
> warning about the u64 to unsigned long assignment on 32 bit arches.

My local i386-defconfig build seemed happy now. Mostly I think you're
allowed to silently truncate between base integer types. We'll see..
maybe some other compiler.

> Perhaps it needs something ugly like this:
> 
> 	info.si_addr = (void __user *)(unsigned long)event->pending_addr;
> 
> if pending_addr wants to be u64. Or just
> 
> 	event->pending_addr = (unsigned long)data->addr;
> 
> if data->addr being u64 on 32 bit arches is simply overkill.

Yeah it is. It's u64 for data layout purposes, the perf buffer works in
u64 chunks.

^ permalink raw reply	[flat|nested] 9+ messages in thread
end of thread, other threads:[~2021-04-15  9:12 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-14 14:10 [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces) kernel test robot
2021-04-14 14:33 ` Marco Elver
2021-04-14 14:33   ` Marco Elver
2021-04-15  8:48   ` Peter Zijlstra
2021-04-15  8:48     ` Peter Zijlstra
2021-04-15  9:03     ` Marco Elver
2021-04-15  9:03       ` Marco Elver
2021-04-15  9:11       ` Peter Zijlstra
2021-04-15  9:11         ` Peter Zijlstra

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