kernel.git/arch/x86/include/asm/thread_info.h, branch linux-3.10.y

uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME

2014-12-06T23:05:46Z

commit 82975bc6a6df743b9a01810fb32cb65d0ec5d60b upstream. x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but not on non-paranoid returns. I suspect that this is a mistake and that the code only works because int3 is paranoid. Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME from the uprobes code. Reported-by: Oleg Nesterov Acked-by: Srikar Dronamraju Acked-by: Borislav Petkov Signed-off-by: Andy Lutomirski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

arch: Consolidate tsk_is_polling()

2013-04-08T15:39:22Z

Move it to a common place. Preparatory patch for implementing set/clear for the idle need_resched poll implementation. Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Rusty Russell Cc: Paul McKenney Cc: Peter Zijlstra Reviewed-by: Cc: Srivatsa S. Bhat Cc: Magnus Damm Link: http://lkml.kernel.org/r/20130321215233.446034505@linutronix.de Signed-off-by: Thomas Gleixner

tracing/syscalls: Allow archs to ignore tracing compat syscalls

2013-02-12T22:46:28Z

The tracing of ia32 compat system calls has been a bit of a pain as they use different system call numbers than the 64bit equivalents. I wrote a simple 'lls' program that lists files. I compiled it as a i686 ELF binary and ran it under a x86_64 box. This is the result: echo 0 > /debug/tracing/tracing_on echo 1 > /debug/tracing/events/syscalls/enable echo 1 > /debug/tracing/tracing_on ; ./lls ; echo 0 > /debug/tracing/tracing_on grep lls /debug/tracing/trace [.. skipping calls before TS_COMPAT is set ...] lls-1127 [005] d... 936.409188: sys_recvfrom(fd: 0, ubuf: 4d560fc4, size: 0, flags: 8048034, addr: 8, addr_len: f7700420) lls-1127 [005] d... 936.409190: sys_recvfrom -> 0x8a77000 lls-1127 [005] d... 936.409211: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) lls-1127 [005] d... 936.409215: sys_lgetxattr -> 0xf76ff000 lls-1127 [005] d... 936.409223: sys_dup2(oldfd: 4d55ae9b, newfd: 4) lls-1127 [005] d... 936.409228: sys_dup2 -> 0xfffffffffffffffe lls-1127 [005] d... 936.409236: sys_newfstat(fd: 4d55b085, statbuf: 80000) lls-1127 [005] d... 936.409242: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409243: sys_removexattr(pathname: 3, name: ffcd0060) lls-1127 [005] d... 936.409244: sys_removexattr -> 0x0 lls-1127 [005] d... 936.409245: sys_lgetxattr(pathname: 0, name: 19614, value: 1, size: 2) lls-1127 [005] d... 936.409248: sys_lgetxattr -> 0xf76e5000 lls-1127 [005] d... 936.409248: sys_newlstat(filename: 3, statbuf: 19614) lls-1127 [005] d... 936.409249: sys_newlstat -> 0x0 lls-1127 [005] d... 936.409262: sys_newfstat(fd: f76fb588, statbuf: 80000) lls-1127 [005] d... 936.409279: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409279: sys_close(fd: 3) lls-1127 [005] d... 936.421550: sys_close -> 0x200 lls-1127 [005] d... 936.421558: sys_removexattr(pathname: 3, name: ffcd00d0) lls-1127 [005] d... 936.421560: sys_removexattr -> 0x0 lls-1127 [005] d... 936.421569: sys_lgetxattr(pathname: 4d564000, name: 1b1abc, value: 5, size: 802) lls-1127 [005] d... 936.421574: sys_lgetxattr -> 0x4d564000 lls-1127 [005] d... 936.421575: sys_capget(header: 4d70f000, dataptr: 1000) lls-1127 [005] d... 936.421580: sys_capget -> 0x0 lls-1127 [005] d... 936.421580: sys_lgetxattr(pathname: 4d710000, name: 3000, value: 3, size: 812) lls-1127 [005] d... 936.421589: sys_lgetxattr -> 0x4d710000 lls-1127 [005] d... 936.426130: sys_lgetxattr(pathname: 4d713000, name: 2abc, value: 3, size: 32) lls-1127 [005] d... 936.426141: sys_lgetxattr -> 0x4d713000 lls-1127 [005] d... 936.426145: sys_newlstat(filename: 3, statbuf: f76ff3f0) lls-1127 [005] d... 936.426146: sys_newlstat -> 0x0 lls-1127 [005] d... 936.431748: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) Obviously I'm not calling newfstat with a fd of 4d55b085. The calls are obviously incorrect, and confusing. Other efforts have been made to fix this: https://lkml.org/lkml/2012/3/26/367 But the real solution is to rewrite the syscall internals and come up with a fixed solution. One that doesn't require all the kluge that the current solution has. Thus for now, instead of outputting incorrect data, simply ignore them. With this patch the changes now have: #> grep lls /debug/tracing/trace #> Compat system calls simply are not traced. If users need compat syscalls, then they should just use the raw syscall tracepoints. For an architecture to make their compat syscalls ignored, it must define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS (done in asm/ftrace.h) and also define an arch_trace_is_compat_syscall() function that will return true if the current task should ignore tracing the syscall. I want to stress that this change does not affect actual syscalls in any way, shape or form. It is only used within the tracing system and doesn't interfere with the syscall logic at all. The changes are consolidated nicely into trace_syscalls.c and asm/ftrace.h. I had to make one small modification to asm/thread_info.h and that was to remove the include of asm/ftrace.h. As asm/ftrace.h required the current_thread_info() it was causing include hell. That include was added back in 2008 when the function graph tracer was added: commit caf4b323 "tracing, x86: add low level support for ftrace return tracing" It does not need to be included there. Link: http://lkml.kernel.org/r/1360703939.21867.99.camel@gandalf.local.home Acked-by: H. Peter Anvin Signed-off-by: Steven Rostedt

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2012-10-10T03:02:25Z

Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...

x86: Syscall hooks for userspace RCU extended QS

2012-09-26T13:47:04Z

Add syscall slow path hooks to notify syscall entry and exit on CPUs that want to support userspace RCU extended quiescent state. Signed-off-by: Frederic Weisbecker Cc: Alessio Igor Bogani Cc: Andrew Morton Cc: Avi Kivity Cc: Chris Metcalf Cc: Christoph Lameter Cc: Geoff Levand Cc: Gilad Ben Yossef Cc: Hakan Akkan Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Josh Triplett Cc: Kevin Hilman Cc: Max Krasnyansky Cc: Peter Zijlstra Cc: Stephen Hemminger Cc: Steven Rostedt Cc: Sven-Thorsten Dietrich Cc: Thomas Gleixner Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett

x86: get rid of TIF_IRET hackery

2012-09-20T13:50:17Z

TIF_NOTIFY_RESUME will work in precisely the same way; all that is achieved by TIF_IRET is appearing that there's some work to be done, so we end up on the iret exit path. Just use NOTIFY_RESUME. And for execve() do that in 32bit start_thread(), not sys_execve() itself. Signed-off-by: Al Viro

set_restore_sigmask() is never called without SIGPENDING (and never should be)

2012-06-01T16:58:50Z

Signed-off-by: Al Viro

new helpers: {clear,test,test_and_clear}_restore_sigmask()

2012-06-01T16:58:47Z

helpers parallel to set_restore_sigmask(), used in the next commits Signed-off-by: Al Viro

Merge branch 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-05-24T18:39:34Z

Pull user-space probe instrumentation from Ingo Molnar: "The uprobes code originates from SystemTap and has been used for years in Fedora and RHEL kernels. This version is much rewritten, reviews from PeterZ, Oleg and myself shaped the end result. This tree includes uprobes support in 'perf probe' - but SystemTap (and other tools) can take advantage of user probe points as well. Sample usage of uprobes via perf, for example to profile malloc() calls without modifying user-space binaries. First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled. If you don't know which function you want to probe you can pick one from 'perf top' or can get a list all functions that can be probed within libc (binaries can be specified as well): $ perf probe -F -x /lib/libc.so.6 To probe libc's malloc(): $ perf probe -x /lib64/libc.so.6 malloc Added new event: probe_libc:malloc (on 0x7eac0) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 Make use of it to create a call graph (as the flat profile is going to look very boring): $ perf record -e probe_libc:malloc -gR make [ perf record: Woken up 173 times to write data ] [ perf record: Captured and wrote 44.190 MB perf.data (~1930712 $ perf report | less 32.03% git libc-2.15.so [.] malloc | --- malloc 29.49% cc1 libc-2.15.so [.] malloc | --- malloc | |--0.95%-- 0x208eb1000000000 | |--0.63%-- htab_traverse_noresize 11.04% as libc-2.15.so [.] malloc | --- malloc | 7.15% ld libc-2.15.so [.] malloc | --- malloc | 5.07% sh libc-2.15.so [.] malloc | --- malloc | 4.99% python-config libc-2.15.so [.] malloc | --- malloc | 4.54% make libc-2.15.so [.] malloc | --- malloc | |--7.34%-- glob | | | |--93.18%-- 0x41588f | | | --6.82%-- glob | 0x41588f ... Or: $ perf report -g flat | less # Overhead Command Shared Object Symbol # ........ ............. ............. .......... # 32.03% git libc-2.15.so [.] malloc 27.19% malloc 29.49% cc1 libc-2.15.so [.] malloc 24.77% malloc 11.04% as libc-2.15.so [.] malloc 11.02% malloc 7.15% ld libc-2.15.so [.] malloc 6.57% malloc ... The core uprobes design is fairly straightforward: uprobes probe points register themselves at (inode:offset) addresses of libraries/binaries, after which all existing (or new) vmas that map that address will have a software breakpoint injected at that address. vmas are COW-ed to preserve original content. The probe points are kept in an rbtree. If user-space executes the probed inode:offset instruction address then an event is generated which can be recovered from the regular perf event channels and mmap-ed ring-buffer. Multiple probes at the same address are supported, they create a dynamic callback list of event consumers. The basic model is further complicated by the XOL speedup: the original instruction that is probed is copied (in an architecture specific fashion) and executed out of line when the probe triggers. The XOL area is a single vma per process, with a fixed number of entries (which limits probe execution parallelism). The API: uprobes are installed/removed via /sys/kernel/debug/tracing/uprobe_events, the API is integrated to align with the kprobes interface as much as possible, but is separate to it. Injecting a probe point is privileged operation, which can be relaxed by setting perf_paranoid to -1. You can use multiple probes as well and mix them with kprobes and regular PMU events or tracepoints, when instrumenting a task." Fix up trivial conflicts in mm/memory.c due to previous cleanup of unmap_single_vma(). * 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf probe: Detect probe target when m/x options are absent perf probe: Provide perf interface for uprobes tracing: Fix kconfig warning due to a typo tracing: Provide trace events interface for uprobes tracing: Extract out common code for kprobes/uprobes trace events tracing: Modify is_delete, is_return from int to bool uprobes/core: Decrement uprobe count before the pages are unmapped uprobes/core: Make background page replacement logic account for rss_stat counters uprobes/core: Optimize probe hits with the help of a counter uprobes/core: Allocate XOL slots for uprobes use uprobes/core: Handle breakpoint and singlestep exceptions uprobes/core: Rename bkpt to swbp uprobes/core: Make order of function parameters consistent across functions uprobes/core: Make macro names consistent uprobes: Update copyright notices uprobes/core: Move insn to arch specific structure uprobes/core: Remove uprobe_opcode_sz uprobes/core: Make instruction tables volatile uprobes: Move to kernel/events/ uprobes/core: Clean up, refactor and improve the code ...

Merge branch 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2012-05-23T00:37:47Z

Pull percpu updates from Tejun Heo: "Contains Alex Shi's three patches to remove percpu_xxx() which overlap with this_cpu_xxx(). There shouldn't be any functional change." * 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: remove percpu_xxx() functions x86: replace percpu_xxx funcs with this_cpu_xxx net: replace percpu_xxx funcs with this_cpu_xxx or __this_cpu_xxx