- Jun 06, 2012
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Peter Zijlstra authored
Move the wrmslr() debug wrapper to the common header now that all the include games are gone. Also clean it up a bit to avoid multiple evaluation of the argument. Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-l4gkfnivwv4yi5mqxjlovymx@git.kernel.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
Afaict there's no need to (incompletely) iterate the MEM_UOPS_RETIRED.* umask state. Signed-off-by:
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Peter Zijlstra authored
Implement rudimentary IVB perf support. The SDM states its identical to SNB with exception of the exact event tables, but a quick look suggests they're similar enough. Also mark SNB-EP as broken for now. Requested-and-tested-by:
Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Signed-off-by:
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Peter Zijlstra authored
Now that there's finally a chip with working PEBS (IvyBridge), we can enable the hardware and implement cycles:p for SNB/IVB. Cc: Stephane Eranian <eranian@google.com> Requested-and-tested-by:
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Peter Zijlstra authored
Zheng Yan reported that event group validation can wreck event state when Intel extra_reg allocation changes event state. Validation shouldn't change any persistent state. Cloning events in validate_{event,group}() isn't really pretty either, so add a few special cases to avoid modifying the event state. The code is restructured to minimize the special case impact. Reported-by:Zheng Yan <zheng.z.yan@linux.intel.com> Acked-by:
Stephane Eranian <eranian@google.com> Signed-off-by:
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Arun Sharma authored
Signed-off-by:
Arun Sharma <asharma@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by:
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Arun Sharma authored
Signed-off-by:
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Arun Sharma authored
Without this patch, applications with two different stack regions (eg: native stack vs JIT stack) get truncated callchains even when RBP chaining is present. GDB shows proper stack traces and the frame pointer chaining is intact. This patch disables the (fp < RSP) check, hoping that other checks in the code save the day for us. In our limited testing, this didn't seem to break anything. In the long term, we could potentially have userspace advise the kernel on the range of valid stack addresses, so we don't spend a lot of time unwinding from bogus addresses. Signed-off-by:
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Peter Zijlstra authored
Afaict there's no need to (incompletely) iterate the MEM_UOPS_RETIRED.* umask state. Signed-off-by:
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Peter Zijlstra authored
Implement rudimentary IVB perf support. The SDM states its identical to SNB with exception of the exact event tables, but a quick look suggests they're similar enough. Also mark SNB-EP as broken for now. Requested-and-tested-by:
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Peter Zijlstra authored
Now that there's finally a chip with working PEBS (IvyBridge), we can enable the hardware and implement cycles:p for SNB/IVB. Cc: Stephane Eranian <eranian@google.com> Requested-and-tested-by:
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Peter Zijlstra authored
Zheng Yan reported that event group validation can wreck event state when Intel extra_reg allocation changes event state. Validation shouldn't change any persistent state. Cloning events in validate_{event,group}() isn't really pretty either, so add a few special cases to avoid modifying the event state. The code is restructured to minimize the special case impact. Reported-by: -
Masami Hiramatsu authored
Fix the x86 instruction decoder to decode bsr/bsf/jmpe with operand-size prefix (66h). This fixes the test case failure reported by Linus, attached below. bsf/bsr/jmpe have a special encoding. Opcode map in Intel Software Developers Manual vol2 says they have TZCNT/LZCNT variants if it has F3h prefix. However, there is no information if it has other 66h or F2h prefixes. Current instruction decoder supposes that those are bad instructions, but it actually accepts at least operand-size prefixes. H. Peter Anvin further explains: " TZCNT/LZCNT are F3 + BSF/BSR exactly because the F2 and F3 prefixes have historically been no-ops with most instructions. This allows software to unconditionally use the prefixed versions and get TZCNT/LZCNT on the processors that have them if they don't care about the difference. " This fixes errors reported by test_get_len: Warning: arch/x86/tools/test_get_len found difference at <em_bsf>:ffffffff81036d87 Warning: ffffffff81036de5: 66 0f bc c2 bsf %dx,%ax Warning: objdump says 4 bytes, but insn_get_length() says 3 Warning: arch/x86/tools/test_get_len found difference at <em_bsr>:ffffffff81036ea6 Warning: ffffffff81036f04: 66 0f bd c2 bsr %dx,%ax Warning: objdump says 4 bytes, but insn_get_length() says 3 Warning: decoded and checked 13298882 instructions with 2 warnings Reported-by:
Pekka Enberg <penberg@kernel.org> Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <yrl.pp-manager.tt@hitachi.com> Link: http://lkml.kernel.org/r/20120604150911.22338.43296.stgit@localhost.localdomain Signed-off-by:
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- Jun 04, 2012
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Al Viro authored
Obvious brainos spotted by Geert. Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
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- Jun 02, 2012
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Anton Blanchard authored
commit e57f93cc (powerpc: get rid of nlink_t uses, switch to explicitly-sized type) changed the size of st_nlink on ppc64 from a long to a short, resulting in boot failures. Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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Geert Uytterhoeven authored
Introduced by commit 6fd84c08 ("TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set") Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by:
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- Jun 01, 2012
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H.J. Lu authored
When I added x32 ptrace to 3.4 kernel, I also include PTRACE_ARCH_PRCTL support for x32 GDB For ARCH_GET_FS/GS, it takes a pointer to int64. But at user level, ARCH_GET_FS/GS takes a pointer to int32. So I have to add x32 ptrace to glibc to handle it with a temporary int64 passed to kernel and copy it back to GDB as int32. Roland suggested that PTRACE_ARCH_PRCTL is obsolete and x32 GDB should use fs_base and gs_base fields of user_regs_struct instead. Accordingly, remove PTRACE_ARCH_PRCTL completely from the x32 code to avoid possible memory overrun when pointer to int32 is passed to kernel. Link: http://lkml.kernel.org/r/CAMe9rOpDzHfS7NH7m1vmD9QRw8SSj4Sc%2BaNOgcWm_WJME2eRsQ@mail.gmail.com Signed-off-by:
H. Peter Anvin <hpa@zytor.com> Cc: <stable@vger.kernel.org> v3.4
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Al Viro authored
If we end up calling do_notify_resume() with !user_mode(refs), it does nothing (do_signal() explicitly bails out and we can't get there with TIF_NOTIFY_RESUME in such situations). Then we jump to resume_userspace_sig, which rechecks the same thing and bails out to resume_kernel, thus breaking the loop. It's easier and cheaper to check *before* calling do_notify_resume() and bail out to resume_kernel immediately. And kill the check in do_signal()... Note that on amd64 we can't get there with !user_mode() at all - asm glue takes care of that. Acked-and-reviewed-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Al Viro authored
Signed-off-by: -
Al Viro authored
blackfin has reintroduced it, completely unused. Signed-off-by: -
David Howells authored
Optimise the system call exit path in entry.S by packing some instructions. Suggested-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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David Howells authored
Shrink TIF_WORK_MASK so that it will fit in the 12-bit signed immediate operand field of an ANDI instruction. Suggested-by:
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David Howells authored
Move the test for kernel mode processing from do_signal() into entry.S to also prevent system call exit tracing and userspace resumption notification handling happening when returning from kernel exceptions. Reported-by:
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Al Viro authored
Does block_sigmask() + tracehook_signal_handler(); called when sigframe has been successfully built. All architectures converted to it; block_sigmask() itself is gone now (merged into this one). I'm still not too happy with the signature, but that's a separate story (IMO we need a structure that would contain signal number + siginfo + k_sigaction, so that get_signal_to_deliver() would fill one, signal_delivered(), handle_signal() and probably setup...frame() - take one). Signed-off-by: -
Al Viro authored
... it's just a call of set_current_blocked() now Signed-off-by: -
Al Viro authored
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(), added set_current_blocked() that will exclude unblockable signals, switched open-coded instances to it. Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
get_signal_to_deliver() will handle it itself Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
it's actually "send me SIGSEGV"... Signed-off-by: -
Al Viro authored
... not if sigframe couldn't have been built. Signed-off-by: -
Al Viro authored
replace boilerplate "should we use ->saved_sigmask or ->blocked?" with calls of obvious inlined helper... Signed-off-by: -
Al Viro authored
first fruits of ..._restore_sigmask() helpers: now we can take boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK and restore the blocked mask from ->saved_mask" into a common helper. Open-coded instances switched... Signed-off-by: -
Al Viro authored
helpers parallel to set_restore_sigmask(), used in the next commits Signed-off-by: -
Matt Fleming authored
Since we can't expect every user to read the EFI boot stub code it seems prudent to have a couple of paragraphs explaining what it is and how it works. The "initrd=" option in particular is tricky because it only understands absolute EFI-style paths (backslashes as directory separators), and until now this hasn't been documented anywhere. This has tripped up a couple of users. Cc: Matthew Garrett <mjg@redhat.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by:
Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1331907517-3985-4-git-send-email-matt@console-pimps.org Signed-off-by:
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Matt Fleming authored
We need a way of printing useful messages to the user, for example when we fail to open an initrd file, instead of just hanging the machine without giving the user any indication of what went wrong. So sprinkle some error messages throughout the EFI boot stub code to make it easier for users to diagnose/report problems. Reported-by:
Keshav P R <the.ridikulus.rat@gmail.com> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by:
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Matt Fleming authored
The loop at the 'close_handles' label in handle_ramdisks() should be using 'i', which represents the number of initrd files that were successfully opened, not 'nr_initrds' which is the number of initrd= arguments passed on the command line. Currently, if we execute the loop to close all file handles and we failed to open any initrds we'll try to call the close function on a garbage pointer, causing the machine to hang. Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by:
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Steven Rostedt authored
When both DYNAMIC_FTRACE and LOCKDEP are set, the TRACE_IRQS_ON/OFF will call into the lockdep code. The lockdep code can call lots of functions that may be traced by ftrace. When ftrace is updating its code and hits a breakpoint, the breakpoint handler will call into lockdep. If lockdep happens to call a function that also has a breakpoint attached, it will jump back into the breakpoint handler resetting the stack to the debug stack and corrupt the contents currently on that stack. The 'do_sym' call that calls do_int3() is protected by modifying the IST table to point to a different location if another breakpoint is hit. But the TRACE_IRQS_OFF/ON are outside that protection, and if a breakpoint is hit from those, the stack will get corrupted, and the kernel will crash: [ 1013.243754] BUG: unable to handle kernel NULL pointer dereference at 0000000000000002 [ 1013.272665] IP: [<ffff880145cc0000>] 0xffff880145cbffff [ 1013.285186] PGD 1401b2067 PUD 14324c067 PMD 0 [ 1013.298832] Oops: 0010 [#1] PREEMPT SMP [ 1013.310600] CPU 2 [ 1013.317904] Modules linked in: ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables crc32c_intel ghash_clmulni_intel microcode usb_debug serio_raw pcspkr iTCO_wdt i2c_i801 iTCO_vendor_support e1000e nfsd nfs_acl auth_rpcgss lockd sunrpc i915 video i2c_algo_bit drm_kms_helper drm i2c_core [last unloaded: scsi_wait_scan] [ 1013.401848] [ 1013.407399] Pid: 112, comm: kworker/2:1 Not tainted 3.4.0+ #30 [ 1013.437943] RIP: 8eb8:[<ffff88014630a000>] [<ffff88014630a000>] 0xffff880146309fff [ 1013.459871] RSP: ffffffff8165e919:ffff88014780f408 EFLAGS: 00010046 [ 1013.477909] RAX: 0000000000000001 RBX: ffffffff81104020 RCX: 0000000000000000 [ 1013.499458] RDX: ffff880148008ea8 RSI: ffffffff8131ef40 RDI: ffffffff82203b20 [ 1013.521612] RBP: ffffffff81005751 R08: 0000000000000000 R09: 0000000000000000 [ 1013.543121] R10: ffffffff82cdc318 R11: 0000000000000000 R12: ffff880145cc0000 [ 1013.564614] R13: ffff880148008eb8 R14: 0000000000000002 R15: ffff88014780cb40 [ 1013.586108] FS: 0000000000000000(0000) GS:ffff880148000000(0000) knlGS:0000000000000000 [ 1013.609458] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1013.627420] CR2: 0000000000000002 CR3: 0000000141f10000 CR4: 00000000001407e0 [ 1013.649051] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1013.670724] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 1013.692376] Process kworker/2:1 (pid: 112, threadinfo ffff88013fe0e000, task ffff88014020a6a0) [ 1013.717028] Stack: [ 1013.724131] ffff88014780f570 ffff880145cc0000 0000400000004000 0000000000000000 [ 1013.745918] cccccccccccccccc ffff88014780cca8 ffffffff811072bb ffffffff81651627 [ 1013.767870] ffffffff8118f8a7 ffffffff811072bb ffffffff81f2b6c5 ffffffff81f11bdb [ 1013.790021] Call Trace: [ 1013.800701] Code: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a <e7> d7 64 81 ff ff ff ff 01 00 00 00 00 00 00 00 65 d9 64 81 ff [ 1013.861443] RIP [<ffff88014630a000>] 0xffff880146309fff [ 1013.884466] RSP <ffff88014780f408> [ 1013.901507] CR2: 0000000000000002 The solution was to reuse the NMI functions that change the IDT table to make the debug stack keep its current stack (in kernel mode) when hitting a breakpoint: call debug_stack_set_zero TRACE_IRQS_ON call debug_stack_reset If the TRACE_IRQS_ON happens to hit a breakpoint then it will keep the current stack and not crash the box. Reported-by:
Dave Jones <davej@redhat.com> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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Steven Rostedt authored
When the NMI handler runs, it checks if it preempted a debug handler and if that handler is using the debug stack. If it is, it changes the IDT table not to update the stack, otherwise it will reset the debug stack and corrupt the debug handler it preempted. Now that ftrace uses breakpoints to change functions from nops to callers, many more places may hit a breakpoint. Unfortunately this includes some of the calls that lockdep performs. Which causes issues with the debug stack. It too needs to change the debug stack before tracing (if called from the debug handler). Allow the debug_stack_set_zero() and debug_stack_reset() to be nested so that the debug handlers can take advantage of them too. [ Used this_cpu_*() over __get_cpu_var() as suggested by H. Peter Anvin ] Signed-off-by:
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