* Re: [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces) [not found] <202104142209.hLOfOONR-lkp@intel.com> @ 2021-04-14 14:33 ` Marco Elver 2021-04-15 8:48 ` Peter Zijlstra 0 siblings, 1 reply; 4+ 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] 4+ 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 ` [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces) Marco Elver @ 2021-04-15 8:48 ` Peter Zijlstra 2021-04-15 9:03 ` Marco Elver 0 siblings, 1 reply; 4+ 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] 4+ 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 2021-04-15 9:11 ` Peter Zijlstra 0 siblings, 1 reply; 4+ 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] 4+ 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 0 siblings, 0 replies; 4+ 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] 4+ messages in thread
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2021-04-14 14:33 ` [peterz-queue:perf/core 18/22] kernel/events/core.c:6418:22: sparse: sparse: incorrect type in assignment (different address spaces) Marco Elver
2021-04-15 8:48 ` Peter Zijlstra
2021-04-15 9:03 ` Marco Elver
2021-04-15 9:11 ` Peter Zijlstra
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