From: "Michal Suchánek" <msuchanek@suse.de>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: linuxppc-dev@lists.ozlabs.org,
Nicholas Piggin <npiggin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpcs: perf: consolidate perf_callchain_user_64 and perf_callchain_user_32
Date: Thu, 9 Apr 2020 13:22:26 +0200 [thread overview]
Message-ID: <20200409112226.GT25468@kitsune.suse.cz> (raw)
In-Reply-To: <8786906b-edd5-e4a3-8286-33a05f39668c@c-s.fr>
On Tue, Apr 07, 2020 at 07:21:06AM +0200, Christophe Leroy wrote:
>
>
> Le 06/04/2020 à 23:00, Michal Suchanek a écrit :
> > perf_callchain_user_64 and perf_callchain_user_32 are nearly identical.
> > Consolidate into one function with thin wrappers.
> >
> > Suggested-by: Nicholas Piggin <npiggin@gmail.com>
> > Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> > ---
> > arch/powerpc/perf/callchain.h | 24 +++++++++++++++++++++++-
> > arch/powerpc/perf/callchain_32.c | 21 ++-------------------
> > arch/powerpc/perf/callchain_64.c | 14 ++++----------
> > 3 files changed, 29 insertions(+), 30 deletions(-)
> >
> > diff --git a/arch/powerpc/perf/callchain.h b/arch/powerpc/perf/callchain.h
> > index 7a2cb9e1181a..7540bb71cb60 100644
> > --- a/arch/powerpc/perf/callchain.h
> > +++ b/arch/powerpc/perf/callchain.h
> > @@ -2,7 +2,7 @@
> > #ifndef _POWERPC_PERF_CALLCHAIN_H
> > #define _POWERPC_PERF_CALLCHAIN_H
> > -int read_user_stack_slow(void __user *ptr, void *buf, int nb);
> > +int read_user_stack_slow(const void __user *ptr, void *buf, int nb);
>
> Does the constification of ptr has to be in this patch ?
It was in the original patch. The code is touched anyway.
> Wouldn't it be better to have it as a separate patch ?
Don't care much either way. Can resend it as separate patches.
>
> > void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
> > struct pt_regs *regs);
> > void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
> > @@ -16,4 +16,26 @@ static inline bool invalid_user_sp(unsigned long sp)
> > return (!sp || (sp & mask) || (sp > top));
> > }
> > +/*
> > + * On 32-bit we just access the address and let hash_page create a
> > + * HPTE if necessary, so there is no need to fall back to reading
> > + * the page tables. Since this is called at interrupt level,
> > + * do_page_fault() won't treat a DSI as a page fault.
> > + */
> > +static inline int __read_user_stack(const void __user *ptr, void *ret,
> > + size_t size)
> > +{
> > + int rc;
> > +
> > + if ((unsigned long)ptr > TASK_SIZE - size ||
> > + ((unsigned long)ptr & (size - 1)))
> > + return -EFAULT;
> > + rc = probe_user_read(ret, ptr, size);
> > +
> > + if (rc && IS_ENABLED(CONFIG_PPC64))
>
> gcc is probably smart enough to deal with it efficiently, but it would
> be more correct to test rc after checking CONFIG_PPC64.
IS_ENABLED(CONFIG_PPC64) is constant so that part of the check should be
compiled out in any case.
Thanks
Michal
next prev parent reply other threads:[~2020-04-09 11:22 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200225173541.1549955-1-npiggin@gmail.com>
2020-03-19 12:19 ` [PATCH v11 0/8] Disable compat cruft on ppc64le v11 Michal Suchanek
2020-03-19 12:19 ` [PATCH v11 1/8] powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro Michal Suchanek
2020-03-19 12:19 ` [PATCH v11 2/8] powerpc: move common register copy functions from signal_32.c to signal.c Michal Suchanek
2020-03-19 12:19 ` [PATCH v11 3/8] powerpc/perf: consolidate read_user_stack_32 Michal Suchanek
2020-03-24 8:48 ` Nicholas Piggin
2020-03-24 19:38 ` Michal Suchánek
2020-04-03 7:13 ` Nicholas Piggin
2020-04-03 10:52 ` Michal Suchánek
2020-04-03 11:26 ` Nicholas Piggin
2020-04-03 11:51 ` Michal Suchánek
2020-04-06 20:52 ` Michal Suchánek
2020-04-06 21:00 ` [PATCH] powerpcs: perf: consolidate perf_callchain_user_64 and perf_callchain_user_32 Michal Suchanek
2020-04-07 5:21 ` Christophe Leroy
2020-04-09 11:22 ` Michal Suchánek [this message]
2020-03-19 12:19 ` [PATCH v11 4/8] powerpc/perf: consolidate valid_user_sp Michal Suchanek
2020-03-19 12:19 ` [PATCH v11 5/8] powerpc/64: make buildable without CONFIG_COMPAT Michal Suchanek
2020-03-24 8:54 ` Nicholas Piggin
2020-03-24 19:30 ` Michal Suchánek
2020-04-03 7:16 ` Nicholas Piggin
2020-03-19 12:19 ` [PATCH v11 6/8] powerpc/64: Make COMPAT user-selectable disabled on littleendian by default Michal Suchanek
2020-03-19 12:19 ` [PATCH v11 7/8] powerpc/perf: split callchain.c by bitness Michal Suchanek
2020-03-19 12:19 ` [PATCH v11 8/8] MAINTAINERS: perf: Add pattern that matches ppc perf to the perf entry Michal Suchanek
2020-03-19 13:37 ` Andy Shevchenko
2020-03-19 14:00 ` Michal Suchánek
2020-03-19 14:26 ` Andy Shevchenko
2020-03-19 17:03 ` Joe Perches
2020-03-19 12:36 ` [PATCH v11 0/8] Disable compat cruft on ppc64le v11 Christophe Leroy
2020-03-19 14:01 ` Michal Suchánek
2020-04-03 7:25 ` Nicholas Piggin
2020-04-03 7:26 ` Christophe Leroy
2020-04-03 9:43 ` Nicholas Piggin
2020-04-05 0:40 ` Michael Ellerman
2020-03-20 10:20 ` [PATCH v12 0/8] Disable compat cruft on ppc64le v12 Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 1/8] powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 2/8] powerpc: move common register copy functions from signal_32.c to signal.c Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 3/8] powerpc/perf: consolidate read_user_stack_32 Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 4/8] powerpc/perf: consolidate valid_user_sp -> invalid_user_sp Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 5/8] powerpc/64: make buildable without CONFIG_COMPAT Michal Suchanek
2020-04-07 5:50 ` Christophe Leroy
2020-04-07 9:57 ` Michal Suchánek
2020-03-20 10:20 ` [PATCH v12 6/8] powerpc/64: Make COMPAT user-selectable disabled on littleendian by default Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 7/8] powerpc/perf: split callchain.c by bitness Michal Suchanek
2020-03-20 10:20 ` [PATCH v12 8/8] MAINTAINERS: perf: Add pattern that matches ppc perf to the perf entry Michal Suchanek
2020-03-20 10:33 ` Andy Shevchenko
2020-03-20 11:23 ` Michal Suchánek
2020-03-20 12:42 ` Andy Shevchenko
2020-03-20 14:42 ` Joe Perches
2020-03-20 16:28 ` Michal Suchánek
2020-03-20 16:31 ` Andy Shevchenko
2020-03-20 16:42 ` Michal Suchánek
2020-03-20 16:47 ` Andy Shevchenko
2020-03-20 21:36 ` Joe Perches
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