- 01 2月, 2017 2 次提交
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由 travis@sgi.com 提交于
Add a low impact health check triggered by the system NMI command that essentially checks which CPUs are responding to external NMI's. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NRuss Anderson <rja@hpe.com> Reviewed-by: NAlex Thorlton <athorlton@sgi.com> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NDimitri Sivanich <sivanich@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170125163517.756690240@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 travis@sgi.com 提交于
Merge new UV Hubless NMI support into existing UV NMI handler. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NRuss Anderson <rja@hpe.com> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NDimitri Sivanich <sivanich@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170125163517.585269837@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 26 10月, 2016 1 次提交
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由 Josh Poimboeuf 提交于
Printing kernel text addresses in stack dumps is of questionable value, especially now that address randomization is becoming common. It can be a security issue because it leaks kernel addresses. It also affects the usefulness of the stack dump. Linus says: "I actually spend time cleaning up commit messages in logs, because useless data that isn't actually information (random hex numbers) is actively detrimental. It makes commit logs less legible. It also makes it harder to parse dumps. It's not useful. That makes it actively bad. I probably look at more oops reports than most people. I have not found the hex numbers useful for the last five years, because they are just randomized crap. The stack content thing just makes code scroll off the screen etc, for example." The only real downside to removing these addresses is that they can be used to disambiguate duplicate symbol names. However such cases are rare, and the context of the stack dump should be enough to be able to figure it out. There's now a 'faddr2line' script which can be used to convert a function address to a file name and line: $ ./scripts/faddr2line ~/k/vmlinux write_sysrq_trigger+0x51/0x60 write_sysrq_trigger+0x51/0x60: write_sysrq_trigger at drivers/tty/sysrq.c:1098 Or gdb can be used: $ echo "list *write_sysrq_trigger+0x51" |gdb ~/k/vmlinux |grep "is in" (gdb) 0xffffffff815b5d83 is in driver_probe_device (/home/jpoimboe/git/linux/drivers/base/dd.c:378). (But note that when there are duplicate symbol names, gdb will only show the first symbol it finds. faddr2line is recommended over gdb because it handles duplicates and it also does function size checking.) Here's an example of what a stack dump looks like after this change: BUG: unable to handle kernel NULL pointer dereference at (null) IP: sysrq_handle_crash+0x45/0x80 PGD 36bfa067 [ 29.650644] PUD 7aca3067 Oops: 0002 [#1] PREEMPT SMP Modules linked in: ... CPU: 1 PID: 786 Comm: bash Tainted: G E 4.9.0-rc1+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 task: ffff880078582a40 task.stack: ffffc90000ba8000 RIP: 0010:sysrq_handle_crash+0x45/0x80 RSP: 0018:ffffc90000babdc8 EFLAGS: 00010296 RAX: ffff880078582a40 RBX: 0000000000000063 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000292 RBP: ffffc90000babdc8 R08: 0000000b31866061 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000007 R14: ffffffff81ee8680 R15: 0000000000000000 FS: 00007ffb43869700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007a3e9000 CR4: 00000000001406e0 Stack: ffffc90000babe00 ffffffff81572d08 ffffffff81572bd5 0000000000000002 0000000000000000 ffff880079606600 00007ffb4386e000 ffffc90000babe20 ffffffff81573201 ffff880036a3fd00 fffffffffffffffb ffffc90000babe40 Call Trace: __handle_sysrq+0x138/0x220 ? __handle_sysrq+0x5/0x220 write_sysrq_trigger+0x51/0x60 proc_reg_write+0x42/0x70 __vfs_write+0x37/0x140 ? preempt_count_sub+0xa1/0x100 ? __sb_start_write+0xf5/0x210 ? vfs_write+0x183/0x1a0 vfs_write+0xb8/0x1a0 SyS_write+0x58/0xc0 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7ffb42f55940 RSP: 002b:00007ffd33bb6b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007ffb42f55940 RDX: 0000000000000002 RSI: 00007ffb4386e000 RDI: 0000000000000001 RBP: 0000000000000011 R08: 00007ffb4321ea40 R09: 00007ffb43869700 R10: 00007ffb43869700 R11: 0000000000000246 R12: 0000000000778a10 R13: 00007ffd33bb5c00 R14: 0000000000000007 R15: 0000000000000010 Code: 34 e8 d0 34 bc ff 48 c7 c2 3b 2b 57 81 be 01 00 00 00 48 c7 c7 e0 dd e5 81 e8 a8 55 ba ff c7 05 0e 3f de 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 e8 4c 49 bc ff 84 c0 75 c3 48 c7 RIP: sysrq_handle_crash+0x45/0x80 RSP: ffffc90000babdc8 CR2: 0000000000000000 Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/69329cb29b8f324bb5fcea14d61d224807fb6488.1477405374.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 14 7月, 2016 1 次提交
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由 Paul Gortmaker 提交于
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. One module.h was converted to moduleparam.h since the file had multiple module_param() in it, and another file had an instance of MODULE_DEVICE_TABLE deleted, since that is a no-op when builtin. Finally, the 32 bit build coverage of olpc_ofw revealed a couple implicit includes, which were pretty self evident to fix based on what gcc was complaining about. Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.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/20160714001901.31603-6-paul.gortmaker@windriver.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 11 12月, 2015 1 次提交
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由 Ingo Molnar 提交于
This build failure triggers on 64-bit allmodconfig: arch/x86/platform/uv/uv_nmi.c:493:2: error: implicit declaration of function ‘clocksource_touch_watchdog’ [-Werror=implicit-function-declaration] which is caused by recent changes exposing a missing clocksource.h include in uv_nmi.c: cc1e24fd x86/vdso: Remove pvclock fixmap machinery this file got clocksource.h indirectly via fixmap.h - that stealth route of header inclusion is now gone. Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 14 9月, 2015 1 次提交
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由 Mike Travis 提交于
The ability to trigger a kdump using the system NMI command was added by commit 12ba6c99 ("x86/UV: Add kdump to UV NMI handler") Author: Mike Travis <travis@sgi.com> Date: Mon Sep 23 16:25:03 2013 -0500 This is useful because when kdump is working the information gathered is more informative than the original per CPU stack traces or "dump" option. However a number of things can go wrong with kdump and then the stack traces are more useful than nothing. The two most common reasons for kdump to not be available are: 1) if a problem occurs during boot before the kdump service is started, or 2) the kdump daemon failed to start. In either case the call to crash_kexec() returns unexpectedly. When this happens uv_nmi_kdump() also sets the uv_nmi_kexec_failed flag which causes the slave CPU's to also return to the NMI handler. Upon this unexpected return to the NMI handler, the NMI handler will revert to the "dump" action which uses show_regs() to obtain a process trace dump for all the CPU's. Other minor changes: The "dump" action now generates both the show_regs() stack trace and show instruction pointer information. Whereas the "ips" action only shows instruction pointers for non-idle CPU's. This is more like an abbreviated "ps" display. Change printk(KERN_DEFAULT...) --> pr_info() Signed-off-by: NMike Travis <travis@sgi.com> Signed-off-by: NGeorge Beshers <gbeshers@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Hedi Berriche <hedi@sgi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 11 9月, 2015 1 次提交
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由 Dave Young 提交于
There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NDave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 28 5月, 2015 1 次提交
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由 Luis R. Rodriguez 提交于
Most code already uses consts for the struct kernel_param_ops, sweep the kernel for the last offending stragglers. Other than include/linux/moduleparam.h and kernel/params.c all other changes were generated with the following Coccinelle SmPL patch. Merge conflicts between trees can be handled with Coccinelle. In the future git could get Coccinelle merge support to deal with patch --> fail --> grammar --> Coccinelle --> new patch conflicts automatically for us on patches where the grammar is available and the patch is of high confidence. Consider this a feature request. Test compiled on x86_64 against: * allnoconfig * allmodconfig * allyesconfig @ const_found @ identifier ops; @@ const struct kernel_param_ops ops = { }; @ const_not_found depends on !const_found @ identifier ops; @@ -struct kernel_param_ops ops = { +const struct kernel_param_ops ops = { }; Generated-by: Coccinelle SmPL Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Junio C Hamano <gitster@pobox.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: cocci@systeme.lip6.fr Cc: linux-kernel@vger.kernel.org Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 14 2月, 2015 1 次提交
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由 Tejun Heo 提交于
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. * Unnecessary buffer size calculation and condition on the lenght removed from intel_cacheinfo.c::show_shared_cpu_map_func(). * uv_nmi_nr_cpus_pr() got overly smart and implemented "..." abbreviation if the output stretched over the predefined 1024 byte buffer. Replaced with plain printk. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Mike Travis <travis@sgi.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 27 8月, 2014 1 次提交
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由 Christoph Lameter 提交于
Use __this_cpu_read instead. Cc: Hedi Berriche <hedi@sgi.com> Cc: Mike Travis <travis@sgi.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NTejun Heo <tj@kernel.org>
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- 05 6月, 2014 1 次提交
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由 Borislav Petkov 提交于
... instead of naked numbers. Stuff in sysrq.c used to set it to 8 which is supposed to mean above default level so set it to DEBUG instead as we're terminating/killing all tasks and we want to be verbose there. Also, correct the check in x86_64_start_kernel which should be >= as we're clearly issuing the string there for all debug levels, not only the magical 10. Signed-off-by: NBorislav Petkov <bp@suse.de> Acked-by: NKees Cook <keescook@chromium.org> Acked-by: NRandy Dunlap <rdunlap@infradead.org> Cc: Joe Perches <joe@perches.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 1月, 2014 3 次提交
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由 Mike Travis 提交于
Fix UV call into kgdb to depend only on whether KGDB is defined and not both KGDB and KDB. This allows the power nmi command to use the gdb remote connection if enabled. Note new action of 'kgdb' needs to be set as well to indicate user wants to wait for gdb to be connected. If it's set to 'kdb' then an error message is displayed if KDB is not configured. Also note that if both KGDB and KDB are enabled, then the action of 'kgdb' or 'kdb' has no affect on which is used. See the KGDB documentation for further information. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/20140114162551.635540667@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
Make uv_register_nmi_notifier() and uv_handle_nmi_ping() static to address sparse warnings. Fix problem where uv_nmi_kexec_failed is unused when CONFIG_KEXEC is not defined. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/20140114162551.480872353@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
Some code added to the debug_core module had KDB dependencies that it shouldn't have. Move the KDB dependent REASON back to the caller to remove the dependency in the debug core code. Update the call from the UV NMI handler to conform to the new interface. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 13 11月, 2013 1 次提交
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由 Jiri Slaby 提交于
Consider a kernel crash in a module, simulated the following way: static int my_init(void) { char *map = (void *)0x5; *map = 3; return 0; } module_init(my_init); When we turn off FRAME_POINTERs, the very first instruction in that function causes a BUG. The problem is that we print IP in the BUG report using %pB (from printk_address). And %pB decrements the pointer by one to fix printing addresses of functions with tail calls. This was added in commit 71f9e598 ("x86, dumpstack: Use %pB format specifier for stack trace") to fix the call stack printouts. So instead of correct output: BUG: unable to handle kernel NULL pointer dereference at 0000000000000005 IP: [<ffffffffa01ac000>] my_init+0x0/0x10 [pb173] We get: BUG: unable to handle kernel NULL pointer dereference at 0000000000000005 IP: [<ffffffffa0152000>] 0xffffffffa0151fff To fix that, we use %pS only for stack addresses printouts (via newly added printk_stack_address) and %pB for regs->ip (via printk_address). I.e. we revert to the old behaviour for all except call stacks. And since from all those reliable is 1, we remove that parameter from printk_address. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: joe@perches.com Cc: jirislaby@gmail.com Link: http://lkml.kernel.org/r/1382706418-8435-1-git-send-email-jslaby@suse.czSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 12 11月, 2013 1 次提交
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由 Ingo Molnar 提交于
This reverts commit 8eba1842. uv_trace() is not used by anything, nor is uv_trace_nmi_func, nor uv_trace_func. That's not how we do instrumentation code in the kernel: we add tracepoints, printk()s, etc. so that everyone not just those with magic kernel modules can debug a system. So remove this unused (and misguied) piece of code. Signed-off-by: NIngo Molnar <mingo@kernel.org> Cc: Mike Travis <travis@sgi.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Hedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/n/tip-tumfBffmr4jmnt8Gyxanoblg@git.kernel.org
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- 04 10月, 2013 1 次提交
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由 Mike Travis 提交于
This patch restores the capability to enter KDB (and KGDB) from the UV NMI handler. This is needed because the UV system console is not capable of sending the 'break' signal to the serial console port. It is also useful when the kernel is hung in such a way that it isn't responding to normal external I/O, so sending 'g' to sysreq-trigger does not work either. Another benefit of the external NMI command is that all the cpus receive the NMI signal at roughly the same time so they are more closely aligned timewise. It utilizes the newly added kgdb_nmicallin function to gain entry to KGDB/KDB by the master. The slaves still enter via the standard kgdb_nmicallback function. It also uses the new 'send_ready' pointer to tell KGDB/KDB to signal the slaves when to proceed into the KGDB slave loop. It is enabled when the nmi action is set to "kdb" and the kernel is built with CONFIG_KDB enabled. Note that if kgdb is connected that interface will be used instead. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NDimitri Sivanich <sivanich@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20131002151418.089692683@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 24 9月, 2013 6 次提交
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由 Ingo Molnar 提交于
GCC warned about: arch/x86/platform/uv/uv_nmi.c: In function ‘uv_nmi_setup’: arch/x86/platform/uv/uv_nmi.c:664:2: warning: the address of ‘uv_nmi_cpu_mask’ will always evaluate as ‘true’ The reason is this code: alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL); BUG_ON(!uv_nmi_cpu_mask); which is not the way to check for alloc_cpumask_var() failures - its return code should be checked instead. Cc: Mike Travis <travis@sgi.com> Link: http://lkml.kernel.org/n/tip-2pXRemsjupmvonbpmmnzleo1@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
This patch adds support for the uvtrace module by providing a skeleton call to the registered trace function. It also provides another separate 'NMI' tracer that is triggered by the system wide 'power nmi' command. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NDimitri Sivanich <sivanich@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20130923212501.185052551@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
If a system has hung and it no longer responds to external events, this patch adds the capability of doing a standard kdump and system reboot then triggered by the system NMI command. It is enabled when the nmi action is changed to "kdump" and the kernel is built with CONFIG_KEXEC enabled. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NDimitri Sivanich <sivanich@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20130923212500.660567460@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
The standard NMI handler dumps the states of all the cpus. This includes a full register dump and stack trace. This can be way more information than what is needed. This patch adds a "summary" dump that is basically a form of the "ps" command. It includes the symbolic IP address as well as the command field and basic process information. It is enabled when the nmi action is changed to "ips". Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NDimitri Sivanich <sivanich@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20130923212500.507922930@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
The current UV NMI handler has not been updated for the changes in the system NMI handler and the perf operations. The UV NMI handler reads an MMR in the UV Hub to check to see if the NMI event was caused by the external 'system NMI' that the operator can initiate on the System Mgmt Controller. The problem arises when the perf tools are running, causing millions of perf events per second on very large CPU count systems. Previously this was okay because the perf NMI handler ran at a higher priority on the NMI call chain and if the NMI was a perf event, it would stop calling other NMI handlers remaining on the NMI call chain. Now the system NMI handler calls all the handlers on the NMI call chain including the UV NMI handler. This causes the UV NMI handler to read the MMRs at the same millions per second rate. This can lead to significant performance loss and possible system failures. It also can cause thousands of 'Dazed and Confused' messages being sent to the system console. This effectively makes perf tools unusable on UV systems. To avoid this excessive overhead when perf tools are running, this code has been optimized to minimize reading of the MMRs as much as possible, by moving to the NMI_UNKNOWN notifier chain. This chain is called only when all the users on the standard NMI_LOCAL call chain have been called and none of them have claimed this NMI. There is an exception where the NMI_LOCAL notifier chain is used. When the perf tools are in use, it's possible that the UV NMI was captured by some other NMI handler and then either ignored or mistakenly processed as a perf event. We set a per_cpu ('ping') flag for those CPUs that ignored the initial NMI, and then send them an IPI NMI signal. The NMI_LOCAL handler on each cpu does not need to read the MMR, but instead checks the in memory flag indicating it was pinged. There are two module variables, 'ping_count' indicating how many requested NMI events occurred, and 'ping_misses' indicating how many stray NMI events. These most likely are perf events so it shows the overhead of the perf NMI interrupts and how many MMR reads were avoided. This patch also minimizes the reads of the MMRs by having the first cpu entering the NMI handler on each node set a per HUB in-memory atomic value. (Having a per HUB value avoids sending lock traffic over NumaLink.) Both types of UV NMIs from the SMI layer are supported. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NDimitri Sivanich <sivanich@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20130923212500.353547733@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
This patch moves the UV NMI support from the x2apic file to a new separate uv_nmi.c file in preparation for the next sequence of patches. It prevents upcoming bloat of the x2apic file, and has the added benefit of putting the upcoming /sys/module parameters under the name 'uv_nmi' instead of 'x2apic_uv_x', which was obscure. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NDimitri Sivanich <sivanich@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20130923212500.183295611@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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