1. 03 Jun, 2016 1 commit
    • Mark Rutland's avatar
      arm64: report CPU number in bad_mode · 8051f4d1
      Mark Rutland authored
      If we take an exception we don't expect (e.g. SError), we report this in
      the bad_mode handler with pr_crit. Depending on the configured log
      level, we may or may not log additional information in functions called
      subsequently. Notably, the messages in dump_stack (including the CPU
      number) are printed with KERN_DEFAULT and may not appear.
      
      Some exceptions have an IMPLEMENTATION DEFINED ESR_ELx.ISS encoding, and
      knowing the CPU number is crucial to correctly decode them. To ensure
      that this is always possible, we should log the CPU number along with
      the ESR_ELx value, so we are not reliant on subsequent logs or
      additional printk configuration options.
      
      This patch logs the CPU number in bad_mode such that it is possible for
      a developer to decode these exceptions, provided access to sufficient
      documentation.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Reported-by: default avatarAl Grant <Al.Grant@arm.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Dave Martin <dave.martin@arm.com>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      8051f4d1
  2. 31 May, 2016 1 commit
  3. 23 May, 2016 1 commit
  4. 20 May, 2016 1 commit
    • Jiri Slaby's avatar
      exit_thread: remove empty bodies · 5f56a5df
      Jiri Slaby authored
      Define HAVE_EXIT_THREAD for archs which want to do something in
      exit_thread. For others, let's define exit_thread as an empty inline.
      
      This is a cleanup before we change the prototype of exit_thread to
      accept a task parameter.
      
      [akpm@linux-foundation.org: fix mips]
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5f56a5df
  5. 16 May, 2016 2 commits
    • Arnaldo Carvalho de Melo's avatar
      perf core: Add a 'nr' field to perf_event_callchain_context · 3b1fff08
      Arnaldo Carvalho de Melo authored
      We will use it to count how many addresses are in the entry->ip[] array,
      excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really
      return the number of entries specified by the user via the relevant
      sysctl, kernel.perf_event_max_contexts, or via the per event
      perf_event_attr.sample_max_stack knob.
      
      This way we keep the perf_sample->ip_callchain->nr meaning, that is the
      number of entries, be it real addresses or PERF_CONTEXT_ entries, while
      honouring the max_stack knobs, i.e. the end result will be max_stack
      entries if we have at least that many entries in a given stack trace.
      
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      3b1fff08
    • Arnaldo Carvalho de Melo's avatar
      perf core: Pass max stack as a perf_callchain_entry context · cfbcf468
      Arnaldo Carvalho de Melo authored
      This makes perf_callchain_{user,kernel}() receive the max stack
      as context for the perf_callchain_entry, instead of accessing
      the global sysctl_perf_event_max_stack.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Milian Wolff <milian.wolff@kdab.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: Wang Nan <wangnan0@huawei.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      cfbcf468
  6. 12 May, 2016 1 commit
  7. 11 May, 2016 3 commits
    • Kees Cook's avatar
      arm64: kernel: Fix incorrect brk randomization · 61462c8a
      Kees Cook authored
      This fixes two issues with the arm64 brk randomziation. First, the
      STACK_RND_MASK was being used incorrectly. The original code was:
      
      	unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
      
      STACK_RND_MASK is 0x7ff (32-bit) or 0x3ffff (64-bit), with 4K pages where
      PAGE_SHIFT is 12:
      
      	#define STACK_RND_MASK	(test_thread_flag(TIF_32BIT) ? \
      						0x7ff >> (PAGE_SHIFT - 12) : \
      						0x3ffff >> (PAGE_SHIFT - 12))
      
      This means the resulting offset from base would be 0x7ff0001 or 0x3ffff0001,
      which is wrong since it creates an unaligned end address. It was likely
      intended to be:
      
      	unsigned long range_end = base + ((STACK_RND_MASK + 1) << PAGE_SHIFT)
      
      Which would result in offsets of 0x800000 (32-bit) and 0x40000000 (64-bit).
      
      However, even this corrected 32-bit compat offset (0x00800000) is much
      smaller than native ARM's brk randomization value (0x02000000):
      
      	unsigned long arch_randomize_brk(struct mm_struct *mm)
      	{
      	        unsigned long range_end = mm->brk + 0x02000000;
      	        return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
      	}
      
      So, instead of basing arm64's brk randomization on mistaken STACK_RND_MASK
      calculations, just use specific corrected values for compat (0x2000000)
      and native arm64 (0x40000000).
      Reviewed-by: default avatarJon Medhurst <tixy@linaro.org>
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      [will: use is_compat_task() as suggested by tixy]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      61462c8a
    • Julien Grall's avatar
      arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str · f228b494
      Julien Grall authored
      The loop that browses the array compat_hwcap_str will stop when a NULL
      is encountered, however NULL is missing at the end of array. This will
      lead to overrun until a NULL is found somewhere in the following memory.
      In reality, this works out because the compat_hwcap2_str array tends to
      follow immediately in memory, and that *is* terminated correctly.
      Furthermore, the unsigned int compat_elf_hwcap is checked before
      printing each capability, so we end up doing the right thing because
      the size of the two arrays is less than 32. Still, this is an obvious
      mistake and should be fixed.
      
      Note for backporting: commit 12d11817 ("arm64: Move
      /proc/cpuinfo handling code") moved this code in v4.4. Prior to that
      commit, the same change should be made in arch/arm64/kernel/setup.c.
      
      Fixes: 44b82b77 "arm64: Fix up /proc/cpuinfo"
      Cc: <stable@vger.kernel.org> # v3.19+ (but see note above prior to v4.4)
      Signed-off-by: default avatarJulien Grall <julien.grall@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      f228b494
    • Suzuki K Poulose's avatar
      arm64: secondary_start_kernel: Remove unnecessary barrier · 99aa0362
      Suzuki K Poulose authored
      Remove the unnecessary smp_wmb(), which was added to make sure
      that the update_cpu_boot_status() completes before we mark the
      CPU online. But update_cpu_boot_status() already has dsb() (required
      for the failing CPUs) to ensure the correct behavior.
      
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
      Reported-by: default avatarDennis Chen <dennis.chen@arm.com>
      Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      99aa0362
  8. 28 Apr, 2016 10 commits
  9. 27 Apr, 2016 1 commit
    • Arnaldo Carvalho de Melo's avatar
      perf core: Allow setting up max frame stack depth via sysctl · c5dfd78e
      Arnaldo Carvalho de Melo authored
      The default remains 127, which is good for most cases, and not even hit
      most of the time, but then for some cases, as reported by Brendan, 1024+
      deep frames are appearing on the radar for things like groovy, ruby.
      
      And in some workloads putting a _lower_ cap on this may make sense. One
      that is per event still needs to be put in place tho.
      
      The new file is:
      
        # cat /proc/sys/kernel/perf_event_max_stack
        127
      
      Chaging it:
      
        # echo 256 > /proc/sys/kernel/perf_event_max_stack
        # cat /proc/sys/kernel/perf_event_max_stack
        256
      
      But as soon as there is some event using callchains we get:
      
        # echo 512 > /proc/sys/kernel/perf_event_max_stack
        -bash: echo: write error: Device or resource busy
        #
      
      Because we only allocate the callchain percpu data structures when there
      is a user, which allows for changing the max easily, its just a matter
      of having no callchain users at that point.
      Reported-and-Tested-by: default avatarBrendan Gregg <brendan.d.gregg@gmail.com>
      Reviewed-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Milian Wolff <milian.wolff@kdab.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: Wang Nan <wangnan0@huawei.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c5dfd78e
  10. 26 Apr, 2016 7 commits
  11. 25 Apr, 2016 12 commits