linux/kernel/ptrace.c, branch v2.6.37

signals: move cred_guard_mutex from task_struct to signal_struct

2010-10-28T01:03:12Z

Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec itself and we can reuse ->cred_guard_mutex for it. Yes, concurrent execve() has no worth. Let's move ->cred_guard_mutex from task_struct to signal_struct. It naturally prevent multiple-threads-inside-exec. Signed-off-by: KOSAKI Motohiro Reviewed-by: Oleg Nesterov Acked-by: Roland McGrath Acked-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ptrace: cleanup ptrace_request()

2010-10-28T01:03:10Z

Use new 'datavp' and 'datalp' variables to remove unnecesary castings. Signed-off-by: Namhyung Kim Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ptrace: change signature of sys_ptrace() and friends

2010-10-28T01:03:10Z

Since userspace API of ptrace syscall defines @addr and @data as void pointers, it would be more appropriate to define them as unsigned long in kernel. Therefore related functions are changed also. 'unsigned long' is typically used in other places in kernel as an opaque data type and that using this helps cleaning up a lot of warnings from sparse. Suggested-by: Arnd Bergmann Signed-off-by: Namhyung Kim Acked-by: Arnd Bergmann Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ptrace: annotate lock context change on exit_ptrace()

2010-10-28T01:03:10Z

exit_ptrace() releases and regrabs tasklist_lock but was missing proper annotation. Add it. Signed-off-by: Namhyung Kim Acked-by: Roland McGrath Cc: Ingo Molnar Cc: Oleg Nesterov Signed-off-by: Linus Torvalds

ptrace: optimize exit_ptrace() for the likely case

2010-08-11T15:59:19Z

exit_ptrace() takes tasklist_lock unconditionally. We need this lock to avoid the race with ptrace_traceme(), it acts as a barrier. Change its caller, forget_original_parent(), to call exit_ptrace() under tasklist_lock. Change exit_ptrace() to drop and reacquire this lock if needed. This allows us to add the fastpath list_empty(ptraced) check. In the likely no-tracees case exit_ptrace() just returns and we avoid the lock() + unlock() sequence. "Zhang, Yanmin" suggested to add this check, and he reports that this change adds about 11% improvement in some tests. Suggested-and-tested-by: "Zhang, Yanmin" Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ptrace: PTRACE_GETFDPIC: fix the unsafe usage of child->mm

2010-05-27T16:12:44Z

Now that Mike Frysinger unified the FDPIC ptrace code, we can fix the unsafe usage of child->mm in ptrace_request(PTRACE_GETFDPIC). We have the reference to task_struct, and ptrace_check_attach() verified the tracee is stopped. But nothing can protect from SIGKILL after that, we must not assume child->mm != NULL. Signed-off-by: Oleg Nesterov Acked-by: Mike Frysinger Acked-by: David Howells Cc: Paul Mundt Cc: Greg Ungerer Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ptrace: unify FDPIC implementations

2010-05-27T16:12:44Z

The Blackfin/FRV/SuperH guys all have the same exact FDPIC ptrace code in their arch handlers (since they were probably copied & pasted). Since these ptrace interfaces are an arch independent aspect of the FDPIC code, unify them in the common ptrace code so new FDPIC ports don't need to copy and paste this fundamental stuff yet again. Signed-off-by: Mike Frysinger Acked-by: Roland McGrath Acked-by: David Howells Acked-by: Paul Mundt Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2010-05-18T15:19:03Z

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits) perf tools: Add mode to build without newt support perf symbols: symbol inconsistency message should be done only at verbose=1 perf tui: Add explicit -lslang option perf options: Type check all the remaining OPT_ variants perf options: Type check OPT_BOOLEAN and fix the offenders perf options: Check v type in OPT_U?INTEGER perf options: Introduce OPT_UINTEGER perf tui: Add workaround for slang < 2.1.4 perf record: Fix bug mismatch with -c option definition perf options: Introduce OPT_U64 perf tui: Add help window to show key associations perf tui: Make <- exit menus too perf newt: Add single key shortcuts for zoom into DSO and threads perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed perf newt: Fix the 'A'/'a' shortcut for annotate perf newt: Make <- exit the ui_browser x86, perf: P4 PMU - fix counters management logic perf newt: Make <- zoom out filters perf report: Report number of events, not samples perf hist: Clarify events_stats fields usage ... Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c

ptrace: Cleanup useless header

2010-04-26T21:42:51Z

BKL isn't present anymore into this file thus we can safely remove smp_lock.h inclusion. Signed-off-by: Alessio Igor Bogani Cc: Roland McGrath Cc: Oleg Nesterov Cc: Andrew Morton Cc: James Morris Cc: Ingo Molnar Signed-off-by: Frederic Weisbecker

ptrace: kill BKL in ptrace syscall

2010-04-10T13:34:21Z

The comment suggests that this usage is stale. There is no bkl in the exec path so if there is a race lurking there, the bkl in ptrace is not going to help in this regard. Overview of the possibility of "accidental" races this bkl might protect: - ptrace_traceme() is protected against task removal and concurrent read/write on current->ptrace as it locks write tasklist_lock. - arch_ptrace_attach() is serialized by ptrace_traceme() against concurrent PTRACE_TRACEME or PTRACE_ATTACH - ptrace_attach() is protected the same way ptrace_traceme() and in turn serializes arch_ptrace_attach() - ptrace_check_attach() does its own well described serializing too. There is no obvious race here. Signed-off-by: Arnd Bergmann Signed-off-by: Frederic Weisbecker Acked-by: Oleg Nesterov Acked-by: Roland McGrath Cc: Andrew Morton Cc: Roland McGrath