1. 17 Dec, 2018 1 commit
    • Thomas Richter's avatar
      s390/cpum_cf: Reject request for sampling in event initialization · 696c3ede
      Thomas Richter authored
      [ Upstream commit 613a41b0d16e617f46776a93b975a1eeea96417c ]
      
      On s390 command perf top fails
      [root@s35lp76 perf] # ./perf top -F100000  --stdio
         Error:
         cycles: PMU Hardware doesn't support sampling/overflow-interrupts.
         	Try 'perf stat'
      [root@s35lp76 perf] #
      
      Using event -e rb0000 works as designed.  Event rb0000 is the event
      number of the sampling facility for basic sampling.
      
      During system start up the following PMUs are installed in the kernel's
      PMU list (from head to tail):
         cpum_cf --> s390 PMU counter facility device driver
         cpum_sf --> s390 PMU sampling facility device driver
         uprobe
         kprobe
         tracepoint
         task_clock
         cpu_clock
      
      Perf top executes following functions and calls perf_event_open(2) system
      call with different parameters many times:
      
      cmd_top
      --> __cmd_top
          --> perf_evlist__add_default
              --> __perf_evlist__add_default
                  --> perf_evlist__new_cycles (creates event type:0 (HW)
      			    		config 0 (CPU_CYCLES)
      	        --> perf_event_attr__set_max_precise_ip
      		    Uses perf_event_open(2) to detect correct
      		    precise_ip level. Fails 3 times on s390 which is ok.
      
      Then functions cmd_top
      --> __cmd_top
          --> perf_top__start_counters
              -->perf_evlist__config
      	   --> perf_can_comm_exec
                     --> perf_probe_api
      	           This functions test support for the following events:
      		   "cycles:u", "instructions:u", "cpu-clock:u" using
      		   --> perf_do_probe_api
      		       --> perf_event_open_cloexec
      		           Test the close on exec flag support with
      			   perf_event_open(2).
      	               perf_do_probe_api returns true if the event is
      		       supported.
      		       The function returns true because event cpu-clock is
      		       supported by the PMU cpu_clock.
      	               This is achieved by many calls to perf_event_open(2).
      
      Function perf_top__start_counters now calls perf_evsel__open() for every
      event, which is the default event cpu_cycles (config:0) and type HARDWARE
      (type:0) which a predfined frequence of 4000.
      
      Given the above order of the PMU list, the PMU cpum_cf gets called first
      and returns 0, which indicates support for this sampling. The event is
      fully allocated in the function perf_event_open (file kernel/event/core.c
      near line 10521 and the following check fails:
      
              event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
      		                 NULL, NULL, cgroup_fd);
      	if (IS_ERR(event)) {
      		err = PTR_ERR(event);
      		goto err_cred;
      	}
      
              if (is_sampling_event(event)) {
      		if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
      			err = -EOPNOTSUPP;
      			goto err_alloc;
      		}
      	}
      
      The check for the interrupt capabilities fails and the system call
      perf_event_open() returns -EOPNOTSUPP (-95).
      
      Add a check to return -ENODEV when sampling is requested in PMU cpum_cf.
      This allows common kernel code in the perf_event_open() system call to
      test the next PMU in above list.
      
      Fixes: 97b1198f (" "s390, perf: Use common PMU interrupt disabled code")
      Signed-off-by: default avatarThomas Richter <tmricht@linux.ibm.com>
      Reviewed-by: default avatarHendrik Brueckner <brueckner@linux.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      696c3ede
  2. 01 Dec, 2018 1 commit
  3. 27 Nov, 2018 2 commits
  4. 13 Nov, 2018 1 commit
  5. 20 Oct, 2018 1 commit
  6. 04 Oct, 2018 2 commits
  7. 19 Sep, 2018 1 commit
  8. 15 Sep, 2018 2 commits
  9. 05 Sep, 2018 5 commits
  10. 24 Aug, 2018 1 commit
  11. 03 Aug, 2018 2 commits
  12. 11 Jul, 2018 1 commit
  13. 30 May, 2018 1 commit
  14. 25 May, 2018 9 commits
  15. 22 May, 2018 2 commits
  16. 19 May, 2018 1 commit
    • Jiri Slaby's avatar
      futex: Remove duplicated code and fix undefined behaviour · 81da9f87
      Jiri Slaby authored
      commit 30d6e0a4 upstream.
      
      There is code duplicated over all architecture's headers for
      futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
      and comparison of the result.
      
      Remove this duplication and leave up to the arches only the needed
      assembly which is now in arch_futex_atomic_op_inuser.
      
      This effectively distributes the Will Deacon's arm64 fix for undefined
      behaviour reported by UBSAN to all architectures. The fix was done in
      commit 5f16a046 (arm64: futex: Fix undefined behaviour with
      FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.
      
      And as suggested by Thomas, check for negative oparg too, because it was
      also reported to cause undefined behaviour report.
      
      Note that s390 removed access_ok check in d12a2970 ("s390/uaccess:
      remove pointless access_ok() checks") as access_ok there returns true.
      We introduce it back to the helper for the sake of simplicity (it gets
      optimized away anyway).
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Acked-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390]
      Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
      Reviewed-by: default avatarDarren Hart (VMware) <dvhart@infradead.org>
      Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64]
      Cc: linux-mips@linux-mips.org
      Cc: Rich Felker <dalias@libc.org>
      Cc: linux-ia64@vger.kernel.org
      Cc: linux-sh@vger.kernel.org
      Cc: peterz@infradead.org
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: sparclinux@vger.kernel.org
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: linux-s390@vger.kernel.org
      Cc: linux-arch@vger.kernel.org
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: linux-hexagon@vger.kernel.org
      Cc: Helge Deller <deller@gmx.de>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: linux-snps-arc@lists.infradead.org
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: linux-xtensa@linux-xtensa.org
      Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
      Cc: openrisc@lists.librecores.org
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Stafford Horne <shorne@gmail.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: linux-parisc@vger.kernel.org
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: linux-alpha@vger.kernel.org
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: "David S. Miller" <davem@davemloft.net>
      Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
      Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      81da9f87
  17. 09 May, 2018 1 commit
  18. 29 Apr, 2018 6 commits