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4 commits

Author SHA1 Message Date
Linus Torvalds 84d69848c9 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:

 - EXPORT_SYMBOL for asm source by Al Viro.

   This does bring a regression, because genksyms no longer generates
   checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
   working on a patch to fix this.

   Plus, we are talking about functions like strcpy(), which rarely
   change prototypes.

 - Fixes for PPC fallout of the above by Stephen Rothwell and Nick
   Piggin

 - fixdep speedup by Alexey Dobriyan.

 - preparatory work by Nick Piggin to allow architectures to build with
   -ffunction-sections, -fdata-sections and --gc-sections

 - CONFIG_THIN_ARCHIVES support by Stephen Rothwell

 - fix for filenames with colons in the initramfs source by me.

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
  initramfs: Escape colons in depfile
  ppc: there is no clear_pages to export
  powerpc/64: whitelist unresolved modversions CRCs
  kbuild: -ffunction-sections fix for archs with conflicting sections
  kbuild: add arch specific post-link Makefile
  kbuild: allow archs to select link dead code/data elimination
  kbuild: allow architectures to use thin archives instead of ld -r
  kbuild: Regenerate genksyms lexer
  kbuild: genksyms fix for typeof handling
  fixdep: faster CONFIG_ search
  ia64: move exports to definitions
  sparc32: debride memcpy.S a bit
  [sparc] unify 32bit and 64bit string.h
  sparc: move exports to definitions
  ppc: move exports to definitions
  arm: move exports to definitions
  s390: move exports to definitions
  m68k: move exports to definitions
  alpha: move exports to actual definitions
  x86: move exports to actual definitions
  ...
2016-10-14 14:26:58 -07:00
Ville Syrjälä 65ea11ec6a x86/hweight: Don't clobber %rdi
The caller expects %rdi to remain intact, push+pop it make that happen.

Fixes the following kind of explosions on my core2duo machine when
trying to reboot or shut down:

  general protection fault: 0000 [#1] PREEMPT SMP
  Modules linked in: i915 i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea drm netconsole configfs binfmt_misc iTCO_wdt psmouse pcspkr snd_hda_codec_idt e100 coretemp hwmon snd_hda_codec_generic i2c_i801 mii i2c_smbus lpc_ich mfd_core snd_hda_intel uhci_hcd snd_hda_codec snd_hwdep snd_hda_core ehci_pci 8250 ehci_hcd snd_pcm 8250_base usbcore evdev serial_core usb_common parport_pc parport snd_timer snd soundcore
  CPU: 0 PID: 3070 Comm: reboot Not tainted 4.8.0-rc1-perf-dirty #69
  Hardware name:                  /D946GZIS, BIOS TS94610J.86A.0087.2007.1107.1049 11/07/2007
  task: ffff88012a0b4080 task.stack: ffff880123850000
  RIP: 0010:[<ffffffff81003c92>]  [<ffffffff81003c92>] x86_perf_event_update+0x52/0xc0
  RSP: 0018:ffff880123853b60  EFLAGS: 00010087
  RAX: 0000000000000001 RBX: ffff88012fc0a3c0 RCX: 000000000000001e
  RDX: 0000000000000000 RSI: 0000000040000000 RDI: ffff88012b014800
  RBP: ffff880123853b88 R08: ffffffffffffffff R09: 0000000000000000
  R10: ffffea0004a012c0 R11: ffffea0004acedc0 R12: ffffffff80000001
  R13: ffff88012b0149c0 R14: ffff88012b014800 R15: 0000000000000018
  FS:  00007f8b155cd700(0000) GS:ffff88012fc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f8b155f5000 CR3: 000000012a2d7000 CR4: 00000000000006f0
  Stack:
   ffff88012fc0a3c0 ffff88012b014800 0000000000000004 0000000000000001
   ffff88012fc1b750 ffff880123853bb0 ffffffff81003d59 ffff88012b014800
   ffff88012fc0a3c0 ffff88012b014800 ffff880123853bd8 ffffffff81003e13
  Call Trace:
   [<ffffffff81003d59>] x86_pmu_stop+0x59/0xd0
   [<ffffffff81003e13>] x86_pmu_del+0x43/0x140
   [<ffffffff8111705d>] event_sched_out.isra.105+0xbd/0x260
   [<ffffffff8111738d>] __perf_remove_from_context+0x2d/0xb0
   [<ffffffff8111745d>] __perf_event_exit_context+0x4d/0x70
   [<ffffffff810c8826>] generic_exec_single+0xb6/0x140
   [<ffffffff81117410>] ? __perf_remove_from_context+0xb0/0xb0
   [<ffffffff81117410>] ? __perf_remove_from_context+0xb0/0xb0
   [<ffffffff810c898f>] smp_call_function_single+0xdf/0x140
   [<ffffffff81113d27>] perf_event_exit_cpu_context+0x87/0xc0
   [<ffffffff81113d73>] perf_reboot+0x13/0x40
   [<ffffffff8107578a>] notifier_call_chain+0x4a/0x70
   [<ffffffff81075ad7>] __blocking_notifier_call_chain+0x47/0x60
   [<ffffffff81075b06>] blocking_notifier_call_chain+0x16/0x20
   [<ffffffff81076a1d>] kernel_restart_prepare+0x1d/0x40
   [<ffffffff81076ae2>] kernel_restart+0x12/0x60
   [<ffffffff81076d56>] SYSC_reboot+0xf6/0x1b0
   [<ffffffff811a823c>] ? mntput_no_expire+0x2c/0x1b0
   [<ffffffff811a83e4>] ? mntput+0x24/0x40
   [<ffffffff811894fc>] ? __fput+0x16c/0x1e0
   [<ffffffff811895ae>] ? ____fput+0xe/0x10
   [<ffffffff81072fc3>] ? task_work_run+0x83/0xa0
   [<ffffffff81001623>] ? exit_to_usermode_loop+0x53/0xc0
   [<ffffffff8100105a>] ? trace_hardirqs_on_thunk+0x1a/0x1c
   [<ffffffff81076e6e>] SyS_reboot+0xe/0x10
   [<ffffffff814c4ba5>] entry_SYSCALL_64_fastpath+0x18/0xa3
  Code: 7c 4c 8d af c0 01 00 00 49 89 fe eb 10 48 09 c2 4c 89 e0 49 0f b1 55 00 4c 39 e0 74 35 4d 8b a6 c0 01 00 00 41 8b 8e 60 01 00 00 <0f> 33 8b 35 6e 02 8c 00 48 c1 e2 20 85 f6 7e d2 48 89 d3 89 cf
  RIP  [<ffffffff81003c92>] x86_perf_event_update+0x52/0xc0
   RSP <ffff880123853b60>
  ---[ end trace 7ec95181faf211be ]---
  note: reboot[3070] exited with preempt_count 2

Cc: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Fixes: f5967101e9 ("x86/hweight: Get rid of the special calling convention")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-08 10:58:25 -07:00
Al Viro 784d5699ed x86: move exports to actual definitions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:47:15 -04:00
Borislav Petkov f5967101e9 x86/hweight: Get rid of the special calling convention
People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench
into kcov, lto, etc, experimentations.

Add asm versions for __sw_hweight{32,64}() and do explicit saving and
restoring of clobbered registers. This gets rid of the special calling
convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs.

We still need to hardcode POPCNT and register operands as some old gas
versions which we support, do not know about POPCNT.

Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives
can do padding now.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:01:02 +02:00