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path: root/arch/x86/kernel/entry_32.S
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2009-12-10x86, 32-bit: Use same regs as 64-bit for kernel_thread_helperBrian Gerst
The arg should be in %eax, but that is clobbered by the return value of clone. The function pointer can be in any register. Also, don't push args onto the stack, since regparm(3) is the normal calling convention now. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260380084-3707-4-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-09x86-32: Avoid pipeline serialization in PTREGSCALL1 and 2H. Peter Anvin
In the PTREGSCALL1 and 2 macros, we can trivially avoid an unnecessary pipeline serialization, so do so. In PTREGSCALLS3 this is much less clear-cut since we have to push a new value to the stack. Leave it alone for now assuming it is as good as it is going to be; may want to check on Atom or another in-order x86 to see if we can do better. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-2-git-send-email-brgerst@gmail.com>
2009-12-09x86: Merge sys_cloneBrian Gerst
Change 32-bit sys_clone to new PTREGSCALL stub, and merge with 64-bit. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-7-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-09x86, 32-bit: Convert sys_vm86 & sys_vm86oldBrian Gerst
Convert these to new PTREGSCALL stubs. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-6-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-09x86: Merge sys_sigaltstackBrian Gerst
Change 32-bit sys_sigaltstack to PTREGSCALL2, and merge with 64-bit. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-5-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-09x86: Merge sys_execveBrian Gerst
Change 32-bit sys_execve to PTREGSCALL3, and merge with 64-bit. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-4-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-09x86: Merge sys_ioplBrian Gerst
Change 32-bit sys_iopl to PTREGSCALL1, and merge with 64-bit. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-3-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-09x86-32: Add new pt_regs stubsBrian Gerst
Add new stubs which add the pt_regs pointer as the last arg, matching 64-bit. This will allow these syscalls to be easily merged. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260403316-5679-2-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-10-23Merge branch 'perf/core' into perf/probesIngo Molnar
Conflicts: tools/perf/Makefile Merge reason: - fix the conflict - pick up the pr_*() infrastructure to queue up dependent patch Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-14function-graph/x86: Replace unbalanced ret with jmpSteven Rostedt
The function graph tracer replaces the return address with a hook to trace the exit of the function call. This hook will finish by returning to the real location the function should return to. But the current implementation uses a ret to jump to the real return location. This causes a imbalance between calls and ret. That is the original function does a call, the ret goes to the handler and then the handler does a ret without a matching call. Although the function graph tracer itself still breaks the branch predictor by replacing the original ret, by using a second ret and causing an imbalance, it breaks the predictor even more. This patch replaces the ret with a jmp to keep the calls and ret balanced. I tested this on one box and it showed a 1.7% increase in performance. Another box only showed a small 0.3% increase. But no box that I tested this on showed a decrease in performance by making this change. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091013203425.042034383@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-11kprobes/x86-32: Move irq-exit functions to kprobes sectionMasami Hiramatsu
Move irq-exit functions to .kprobes.text section to protect against kprobes recursion. When I ran kprobe stress test on x86-32, I found below symbols cause unrecoverable recursive probing: ret_from_exception ret_from_intr check_userspace restore_all restore_all_notrace restore_nocheck irq_return And also, I found some interrupt/exception entry points that cause similar problems. This patch moves those symbols (including their container functions) to .kprobes.text section to prevent any kprobes probing. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20090908164755.24050.81182.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-20Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits) tracing/urgent: warn in case of ftrace_start_up inbalance tracing/urgent: fix unbalanced ftrace_start_up function-graph: add stack frame test function-graph: disable when both x86_32 and optimize for size are configured ring-buffer: have benchmark test print to trace buffer ring-buffer: do not grab locks in nmi ring-buffer: add locks around rb_per_cpu_empty ring-buffer: check for less than two in size allocation ring-buffer: remove useless compile check for buffer_page size ring-buffer: remove useless warn on check ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index tracing: update sample event documentation tracing/filters: fix race between filter setting and module unload tracing/filters: free filter_string in destroy_preds() ring-buffer: use commit counters for commit pointer accounting ring-buffer: remove unused variable ring-buffer: have benchmark test handle discarded events ring-buffer: prevent adding write in discarded area tracing/filters: strloc should be unsigned short tracing/filters: operand can be negative ... Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
2009-06-18function-graph: add stack frame testSteven Rostedt
In case gcc does something funny with the stack frames, or the return from function code, we would like to detect that. An arch may implement passing of a variable that is unique to the function and can be saved on entering a function and can be tested when exiting the function. Usually the frame pointer can be used for this purpose. This patch also implements this for x86. Where it passes in the stack frame of the parent function, and will test that frame on exit. There was a case in x86_32 with optimize for size (-Os) where, for a few functions, gcc would align the stack frame and place a copy of the return address into it. The function graph tracer modified the copy and not the actual return address. On return from the funtion, it did not go to the tracer hook, but returned to the parent. This broke the function graph tracer, because the return of the parent (where gcc did not do this funky manipulation) returned to the location that the child function was suppose to. This caused strange kernel crashes. This test detected the problem and pointed out where the issue was. This modifies the parameters of one of the functions that the arch specific code calls, so it includes changes to arch code to accommodate the new prototype. Note, I notice that the parsic arch implements its own push_return_trace. This is now a generic function and the ftrace_push_return_trace should be used instead. This patch does not touch that code. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Helge Deller <deller@gmx.de> Cc: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-17x86: de-assembler-ize asm/desc.hAlexander van Heukelum
asm/desc.h is included in three assembly files, but the only macro it defines, GET_DESC_BASE, is never used. This patch removes the includes, removes the macro GET_DESC_BASE and the ASSEMBLY guard from asm/desc.h. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17i386: fix/simplify espfix stack switching, move it into assemblyAlexander van Heukelum
The espfix code triggers if we have a protected mode userspace application with a 16-bit stack. On returning to userspace, with iret, the CPU doesn't restore the high word of the stack pointer. This is an "official" bug, and the work-around used in the kernel is to temporarily switch to a 32-bit stack segment/pointer pair where the high word of the pointer is equal to the high word of the userspace stackpointer. The current implementation uses THREAD_SIZE to determine the cut-off, but there is no good reason not to use the more natural 64kb... However, implementing this by simply substituting THREAD_SIZE with 65536 in patch_espfix_desc crashed the test application. patch_espfix_desc tries to do what is described above, but gets it subtly wrong if the userspace stack pointer is just below a multiple of THREAD_SIZE: an overflow occurs to bit 13... With a bit of luck, when the kernelspace stackpointer is just below a 64kb-boundary, the overflow then ripples trough to bit 16 and userspace will see its stack pointer changed by 65536. This patch moves all espfix code into entry_32.S. Selecting a 16-bit cut-off simplifies the code. The game with changing the limit dynamically is removed too. It complicates matters and I see no value in it. Changing only the top 16-bit word of ESP is one instruction and it also implies that only two bytes of the ESPFIX GDT entry need to be changed and this can be implemented in just a handful simple to understand instructions. As a side effect, the operation to compute the original ESP from the ESPFIX ESP and the GDT entry simplifies a bit too, and the remaining three instructions have been expanded inline in entry_32.S. impact: can now reliably run userspace with ESP=xxxxfffc on 16-bit stack segment Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Acked-by: Stas Sergeev <stsp@aknet.ru> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17i386: fix return to 16-bit stack from NMI handlerAlexander van Heukelum
Returning to a task with a 16-bit stack requires special care: the iret instruction does not restore the high word of esp in that case. The espfix code fixes this, but currently is not invoked on NMIs. This means that a running task gets the upper word of esp clobbered due intervening NMIs. To reproduce, compile and run the following program with the nmi watchdog enabled (nmi_watchdog=2 on the command line). Using gdb you can see that the high bits of esp contain garbage, while the low bits are still correct. This patch puts the espfix code back into the NMI code path. The patch is slightly complicated due to the irqtrace infrastructure not being NMI-safe. The NMI return path cannot call TRACE_IRQS_IRET. Otherwise, the tail of the normal iret-code is correct for the nmi code path too. To be able to share this code-path, the TRACE_IRQS_IRET was move up a bit. The espfix code exists after the TRACE_IRQS_IRET, but this code explicitly disables interrupts. This short interrupts-off section is now not traced anymore. The return-to-kernel path now always includes the preliminary test to decide if the espfix code should be called. This is never the case, but doing it this way keeps the patch as simple as possible and the few extra instructions should not affect timing in any significant way. #define _GNU_SOURCE #include <stdio.h> #include <sys/types.h> #include <sys/mman.h> #include <unistd.h> #include <sys/syscall.h> #include <asm/ldt.h> int modify_ldt(int func, void *ptr, unsigned long bytecount) { return syscall(SYS_modify_ldt, func, ptr, bytecount); } /* this is assumed to be usable */ #define SEGBASEADDR 0x10000 #define SEGLIMIT 0x20000 /* 16-bit segment */ struct user_desc desc = { .entry_number = 0, .base_addr = SEGBASEADDR, .limit = SEGLIMIT, .seg_32bit = 0, .contents = 0, /* ??? */ .read_exec_only = 0, .limit_in_pages = 0, .seg_not_present = 0, .useable = 1 }; int main(void) { setvbuf(stdout, NULL, _IONBF, 0); /* map a 64 kb segment */ char *pointer = mmap((void *)SEGBASEADDR, SEGLIMIT+1, PROT_EXEC|PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0); if (pointer == NULL) { printf("could not map space\n"); return 0; } /* write ldt, new mode */ int err = modify_ldt(0x11, &desc, sizeof(desc)); if (err) { printf("error modifying ldt: %i\n", err); return 0; } for (int i=0; i<1000; i++) { asm volatile ( "pusha\n\t" "mov %ss, %eax\n\t" /* preserve ss:esp */ "mov %esp, %ebp\n\t" "push $7\n\t" /* index 0, ldt, user mode */ "push $65536-4096\n\t" /* esp */ "lss (%esp), %esp\n\t" /* switch to new stack */ "push %eax\n\t" /* save old ss:esp on new stack */ "push %ebp\n\t" "add $17*65536, %esp\n\t" /* set high bits */ "mov %esp, %edx\n\t" "mov $10000000, %ecx\n\t" /* wait... */ "1: loop 1b\n\t" /* ... a bit */ "cmp %esp, %edx\n\t" "je 1f\n\t" "ud2\n\t" /* esp changed inexplicably! */ "1:\n\t" "sub $17*65536, %esp\n\t" /* restore high bits */ "lss (%esp), %esp\n\t" /* restore old ss:esp */ "popa\n\t"); printf("\rx%ix", i); } return 0; } Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Acked-by: Stas Sergeev <stsp@aknet.ru> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14x86: entry_32.S fix compile warnings - fix work mask bit widthJaswinder Singh Rajput
Fix: arch/x86/kernel/entry_32.S:446: Warning: 00000000080001d1 shortened to 00000000000001d1 arch/x86/kernel/entry_32.S:457: Warning: 000000000800feff shortened to 000000000000feff arch/x86/kernel/entry_32.S:527: Warning: 00000000080001d1 shortened to 00000000000001d1 arch/x86/kernel/entry_32.S:541: Warning: 000000000800feff shortened to 000000000000feff arch/x86/kernel/entry_32.S:676: Warning: 0000000008000091 shortened to 0000000000000091 TIF_SYSCALL_FTRACE is 0x08000000 and until now we checked the first 16 bits of the work mask - bit 27 falls outside of that. Update the entry_32.S code to check the full 32-bit mask. [ %cx => %ecx fix from Cyrill Gorcunov <gorcunov@gmail.com> ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "H. Peter Anvin" <hpa@kernel.org> LKML-Reference: <1237012693.18733.3.camel@ht.satnam> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-23x86: minor cleanup in the espfix codeStas Sergeev
Impact: Cleanup Checkin be44d2aabce2d62f72d5751d1871b6212bf7a1c7 eliminates the use of a 16-bit stack for espfix. However, at least one instruction remained that only operated on the low 16 bits of %esp. This is not a bug per se because the kernel stack is always an aligned 4K or 8K block. Therefore it cannot cross 64K boundaries; this code, in fact, relies strictly on that fact. However, it's a lot cleaner (and, for that matter, smaller) to operate on the entire 32-bit register. Signed-off-by: Stas Sergeev <stsp@aknet.ru> CC: Zachary Amsden <zach@vmware.com> CC: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-13x86: use _types.h headers in asm where availableJeremy Fitzhardinge
In general, the only definitions that assembly files can use are in _types.S headers (where available), so convert them. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-02-13Merge branch 'core/percpu' into x86/coreIngo Molnar
2009-02-11x86: pass in pt_regs pointer for syscalls that need itBrian Gerst
Some syscalls need to access the pt_regs structure, either to copy user register state or to modifiy it. This patch adds stubs to load the address of the pt_regs struct into the %eax register, and changes the syscalls to regparm(1) to receive the pt_regs pointer as the first argument. Signed-off-by: Brian Gerst <brgerst@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10x86: implement x86_32 stack protectorTejun Heo
Impact: stack protector for x86_32 Implement stack protector for x86_32. GDT entry 28 is used for it. It's set to point to stack_canary-20 and have the length of 24 bytes. CONFIG_CC_STACKPROTECTOR turns off CONFIG_X86_32_LAZY_GS and sets %gs to the stack canary segment on entry. As %gs is otherwise unused by the kernel, the canary can be anywhere. It's defined as a percpu variable. x86_32 exception handlers take register frame on stack directly as struct pt_regs. With -fstack-protector turned on, gcc copies the whole structure after the stack canary and (of course) doesn't copy back on return thus losing all changed. For now, -fno-stack-protector is added to all files which contain those functions. We definitely need something better. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10x86: make lazy %gs optional on x86_32Tejun Heo
Impact: pt_regs changed, lazy gs handling made optional, add slight overhead to SAVE_ALL, simplifies error_code path a bit On x86_32, %gs hasn't been used by kernel and handled lazily. pt_regs doesn't have place for it and gs is saved/loaded only when necessary. In preparation for stack protector support, this patch makes lazy %gs handling optional by doing the followings. * Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs. * Save and restore %gs along with other registers in entry_32.S unless LAZY_GS. Note that this unfortunately adds "pushl $0" on SAVE_ALL even when LAZY_GS. However, it adds no overhead to common exit path and simplifies entry path with error code. * Define different user_gs accessors depending on LAZY_GS and add lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS. The lazy_*_gs() ops are used to save, load and clear %gs lazily. * Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly. xen and lguest changes need to be verified. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10x86: use asm .macro instead of cpp #define in entry_32.STejun Heo
Impact: cleanup Use .macro instead of cpp #define where approriate. This cleans up code and will ease future changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-29x86: move mach-default/*.h files to asm/Ingo Molnar
We are getting rid of subarchitecture support - move the hook files to asm/. (These are now stale and should be replaced with more explicit runtime mechanisms - but the transition is simpler this way.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86: make x86_32 use tlb_64.cTejun Heo
Impact: less contention when issuing invalidate IPI, cleanup Make x86_32 use the same tlb code as 64bit. The 64bit code uses multiple IPI vectors for tlb shootdown to reduce contention. This patch makes x86_32 allocate the same 8 IPIs as x86_64 and share the code paths. Note that the usage of asmlinkage is inconsistent for x86_32 and 64 and calls for further cleanup. This has been noted with a FIXME comment in tlb_64.c. Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-12Revert "i386: add TRACE_IRQS_OFF for the nmi"Ingo Molnar
This reverts commit e0c7317557c8fc8eacf611e30c2a80f4e24e47a3. This patch was wrong, as lockdep (and thus the irq state tracer) aren't nmi safe. People are already seeing lockdep warnings due to this. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-28Merge branch 'tracing-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits) sched, trace: update trace_sched_wakeup() tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3 Revert "x86: disable X86_PTRACE_BTS" ring-buffer: prevent false positive warning ring-buffer: fix dangling commit race ftrace: enable format arguments checking x86, bts: memory accounting x86, bts: add fork and exit handling ftrace: introduce tracing_reset_online_cpus() helper tracing: fix warnings in kernel/trace/trace_sched_switch.c tracing: fix warning in kernel/trace/trace.c tracing/ring-buffer: remove unused ring_buffer size trace: fix task state printout ftrace: add not to regex on filtering functions trace: better use of stack_trace_enabled for boot up code trace: add a way to enable or disable the stack tracer x86: entry_64 - introduce FTRACE_ frame macro v2 tracing/ftrace: add the printk-msg-only option tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp() x86, bts: correctly report invalid bts records ... Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits being already partly merged by the SH merge.
2008-12-03ftrace: function graph return for function entrySteven Rostedt
Impact: feature, let entry function decide to trace or not This patch lets the graph tracer entry function decide if the tracing should be done at the end as well. This requires all function graph entry functions return 1 if it should trace, or 0 if the return should not be traced. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03ftrace: have function graph use mcount caller addressSteven Rostedt
Impact: consistency change for function graph This patch makes function graph record the mcount caller address the same way the function tracer does. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28Merge branch 'x86/debug' into x86/irqIngo Molnar
We merge this branch because x86/debug touches code that we started cleaning up in x86/irq. The two branches started out independent, but as unexpected amount of activity went into x86/irq, they became dependent. Resolve that by this cross-merge.
2008-11-27i386: get rid of the use of KPROBE_ENTRY / KPROBE_ENDAlexander van Heukelum
entry_32.S is now the only user of KPROBE_ENTRY / KPROBE_END, treewide. This patch reorders entry_64.S and explicitly generates a separate section for functions that need the protection. The generated code before and after the patch is equal. The KPROBE_ENTRY and KPROBE_END macro's are removed too. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26ftrace: use code patching for ftrace graph tracerSteven Rostedt
Impact: more efficient code for ftrace graph tracer This patch uses the dynamic patching, when available, to patch the function graph code into the kernel. This patch will ease the way for letting both function tracing and function graph tracing run together. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26tracing: function graph tracer, fixIngo Molnar
fix return-tracer => graph-tracer namespace rename fallout. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26tracing/function-return-tracer: change the name into function-graph-tracerFrederic Weisbecker
Impact: cleanup This patch changes the name of the "return function tracer" into function-graph-tracer which is a more suitable name for a tracing which makes one able to retrieve the ordered call stack during the code flow. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23x86, debug: remove the confusing entry in call tracejia zhang
Impact: improve backtrace quality avoid the confusion in call trace because of the lack of padding at the tail of function. When do_exit gets called, the return address behind call instruction is pushed into stack. If something get wrong in do_exit, for x86_64, the entry "kernel_execve +0x00/0xXX" rather than "child_rip +0xYY/0xZZ" is in the call trace. That looks confusing, so add a u2d to make the return address still part of the original call site. (This also catches any instances of us returning from that function somehow.) Signed-off-by: jia zhang <jia.zhang2008@gmail.com> Acked-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16tracing/function-return-tracer: support for dynamic ftrace on function ↵Frederic Weisbecker
return tracer This patch adds the support for dynamic tracing on the function return tracer. The whole difference with normal dynamic function tracing is that we don't need to hook on a particular callback. The only pro that we want is to nop or set dynamically the calls to ftrace_caller (which is ftrace_return_caller here). Some security checks ensure that we are not trying to launch dynamic tracing for return tracing while normal function tracing is already running. An example of trace with getnstimeofday set as a filter: ktime_get_ts+0x22/0x50 -> getnstimeofday (2283 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1396 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1382 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1825 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1426 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1464 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1524 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1382 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1382 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1434 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1464 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1502 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1404 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1397 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1051 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1314 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1344 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1163 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1390 ns) ktime_get_ts+0x22/0x50 -> getnstimeofday (1374 ns) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12tracing/function-return-tracer: call prepare_ftrace_return by registersFrederic Weisbecker
Impact: Optimize a bit the function return tracer This patch changes the calling convention of prepare_ftrace_return to pass its arguments by register. This will optimize it a bit and prepare it to support dynamic tracing. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12x86: fix up the new IRQ code for older versions of gasH. Peter Anvin
Older versions of gas don't implement the C-style != operator, they instead want the Pascal-style <> operator. Change != to <> so we don't break compilation with those old versions of gas. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-11-11x86: 32 bits: shrink and align IRQ stubsH. Peter Anvin
Shrink the IRQ stubs on 32 bits down to just over four bytes per (we fit seven into a 32-byte chunk.) This shrinks the total icache consumption of the IRQ stubs down to an even kilobyte, if all of them are in active use. The downside is that we end up with a double jump, which could have a negative effect on some pipelines. The double jump is always inside the same cacheline on any modern chips (the exception being 486/Elan/Geode which have only 16-byte cachelines, but are unlikely to have too many interrupt sources.) To get the most effect, cache-align the IRQ stubs. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-11-11x86: 32 bit: interrupt stub consistency with 64 bitH. Peter Anvin
Don't generate interrupt stubs for interrupt vectors below FIRST_EXTERNAL_VECTOR, and make the table of interrupt vectors (interrupt[]) __initconst. Both of these changes both conserve memory and improve consistency with 64 bits. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-11-11tracing, x86: add low level support for ftrace return tracingFrederic Weisbecker
Impact: add infrastructure for function-return tracing Add low level support for ftrace return tracing. This plug-in stores return addresses on the thread_info structure of the current task. The index of the current return address is initialized when the task is the first one (init) and when a process forks (the child). It is not needed when a task does a sys_execve because after this syscall, it still needs to return on the kernel functions it called. Note that the code of return_to_handler has been suggested by Steven Rostedt as almost all of the ideas of improvements in this V3. For purpose of security, arch/x86/kernel/process_32.c is not traced because __switch_to() changes the current task during its execution. That could cause inconsistency in the stored return address of this function even if I didn't have any crash after testing with tracing on this function enabled. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06ftrace: add quick function trace stopSteven Rostedt
Impact: quick start and stop of function tracer This patch adds a way to disable the function tracer quickly without the need to run kstop_machine. It adds a new variable called function_trace_stop which will stop the calls to functions from mcount when set. This is just an on/off switch and does not handle recursion like preempt_disable(). It's main purpose is to help other tracers/debuggers start and stop tracing fuctions without the need to call kstop_machine. The config option HAVE_FUNCTION_TRACE_MCOUNT_TEST is added for archs that implement the testing of the function_trace_stop in the mcount arch dependent code. Otherwise, the test is done in the C code. x86 is the only arch at the moment that supports this. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-27Merge commit 'v2.6.28-rc2' into tracing/urgentIngo Molnar
2008-10-22MCE: Don't run 32bit machine checks with interrupts onAndi Kleen
Running machine checks with interrupt on is a extremly bad idea. The machine check handler only runs when the system is broken and needs to finish as quickly as possible. Remove the respective bogus post 2.6.27 regression and call the machine check vector directly again. This removes only code. Signed-off-by: Andi Kleen <ak@linux.intel.com> [Cherry-picked from x86/mce] Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-22Merge branch 'tracing/ftrace' into tracing/urgentIngo Molnar
2008-10-20Merge branch 'tracing-v28-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (131 commits) tracing/fastboot: improve help text tracing/stacktrace: improve help text tracing/fastboot: fix initcalls disposition in bootgraph.pl tracing/fastboot: fix bootgraph.pl initcall name regexp tracing/fastboot: fix issues and improve output of bootgraph.pl tracepoints: synchronize unregister static inline tracepoints: tracepoint_synchronize_unregister() ftrace: make ftrace_test_p6nop disassembler-friendly markers: fix synchronize marker unregister static inline tracing/fastboot: add better resolution to initcall debug/tracing trace: add build-time check to avoid overrunning hex buffer ftrace: fix hex output mode of ftrace tracing/fastboot: fix initcalls disposition in bootgraph.pl tracing/fastboot: fix printk format typo in boot tracer ftrace: return an error when setting a nonexistent tracer ftrace: make some tracers reentrant ring-buffer: make reentrant ring-buffer: move page indexes into page headers tracing/fastboot: only trace non-module initcalls ftrace: move pc counter in irqtrace ... Manually fix conflicts: - init/main.c: initcall tracing - kernel/module.c: verbose level vs tracepoints - scripts/bootgraph.pl: fallout from cherry-picking commits.
2008-10-20ftrace: rename FTRACE to FUNCTION_TRACERSteven Rostedt
Due to confusion between the ftrace infrastructure and the gcc profiling tracer "ftrace", this patch renames the config options from FTRACE to FUNCTION_TRACER. The other two names that are offspring from FTRACE DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same. This patch was generated mostly by script, and partially by hand. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16x86: make 32bit support per_cpu vectorYinghai Lu
so we can merge io_apic_32.c and io_apic_64.c v2: Use cpu_online_map as target cpus for bigsmp, just like 64-bit is doing. Also remove some unused TARGET_CPUS macro. v3: need to check if desc is null in smp_irq_move_cleanup also migration needs to reset vector too, so copy __target_IO_APIC_irq from 64bit. (the duplication will go away once the two files are unified.) Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14ftrace: x86 mcount stubSteven Rostedt
x86 now sets up the mcount locations through the build and no longer needs to record the ip when the function is executed. This patch changes the initial mcount to simply return. There's no need to do any other work. If the ftrace start up test fails, the original mcount will be what everything will use, so having this as fast as possible is a good thing. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>