user/sven/linux.git/kernel, branch v2.6.31.2

perf_counter: Fix perf_copy_attr() pointer arithmetic

2009-10-05T16:31:46Z

commit cdf8073d6b2c6c5a3cd6ce0e6c1297157f7f99ba upstream. There is still some weird code in per_copy_attr(). Which supposedly checks that all bytes trailing a struct are zero. It doesn't seem to get pointer arithmetic right. Since it increments an iterating pointer by sizeof(unsigned long) rather than 1. Signed-off-by: Ian Schram [ v2: clean up the messy PTR_ALIGN logic as well. ] Signed-off-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <4AB3DEE2.3030600@telenet.be> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

perf_counter: Start counting time enabled when group leader gets enabled

2009-09-24T15:43:55Z

commit fa289beca9de9119c7760bd984f3640da21bc94c upstream. Currently, if a group is created where the group leader is initially disabled but a non-leader member is initially enabled, and then the leader is subsequently enabled some time later, the time_enabled for the non-leader member will reflect the whole time since it was created, not just the time since the leader was enabled. This is incorrect, because all of the members are effectively disabled while the leader is disabled, since none of the members can go on the PMU if the leader can't. Thus we have to update the ->tstamp_enabled for all the enabled group members when a group leader is enabled, so that the time_enabled computation only counts the time since the leader was enabled. Similarly, when disabling a group leader we have to update the time_enabled and time_running for all of the group members. Also, in update_counter_times, we have to treat a counter whose group leader is disabled as being disabled. Reported-by: Stephane Eranian Signed-off-by: Paul Mackerras Acked-by: Peter Zijlstra LKML-Reference: <19091.29664.342227.445006@drongo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

perf_counter: Fix buffer overflow in perf_copy_attr()

2009-09-24T15:43:54Z

commit b3e62e35058fc744ac794611f4e79bcd1c5a4b83 upstream. If we pass a big size data over perf_counter_open() syscall, the kernel will copy this data to a small buffer, it will cause kernel crash. This bug makes the kernel unsafe and non-root local user can trigger it. Signed-off-by: Xiao Guangrong Acked-by: Peter Zijlstra Acked-by: Paul Mackerras LKML-Reference: <4AAF37D4.5010706@cn.fujitsu.com> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

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

2009-09-05T20:48:37Z

* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter/powerpc: Fix cache event codes for POWER7 perf_counter: Fix /0 bug in swcounters perf_counters: Increase paranoia level

perf_counter: Fix /0 bug in swcounters

2009-08-29T11:20:11Z

We have a race in the swcounter stuff where we can start counting a counter that has never been enabled, this leads to a /0 situation. The below avoids the /0 but doesn't close the race, this would need a new counter state. The race is due to perf_swcounter_is_counting() which cannot discern between disabled due to scheduled out, and disabled for any other reason. Such a crash has been seen by Ingo: [ 967.092372] divide error: 0000 [#1] SMP [ 967.096499] last sysfs file: /sys/devices/system/cpu/cpu15/cache/index2/shared_cpu_map [ 967.104846] CPU 5 [ 967.106965] Modules linked in: [ 967.110169] Pid: 3351, comm: hackbench Not tainted 2.6.31-rc8-tip-01158-gd940a54-dirty #1568 X8DTN [ 967.119456] RIP: 0010:[] [] perf_swcounter_ctx_event+0x127/0x1af [ 967.129137] RSP: 0018:ffff8801a95abd70 EFLAGS: 00010046 [ 967.134699] RAX: 0000000000000002 RBX: ffff8801bd645c00 RCX: 0000000000000002 [ 967.142162] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801bd645d40 [ 967.149584] RBP: ffff8801a95abdb0 R08: 0000000000000001 R09: ffff8801a95abe00 [ 967.157042] R10: 0000000000000037 R11: ffff8801aa1245f8 R12: ffff8801a95abe00 [ 967.164481] R13: ffff8801a95abe00 R14: ffff8801aa1c0e78 R15: 0000000000000001 [ 967.171953] FS: 0000000000000000(0000) GS:ffffc90000a00000(0063) knlGS:00000000f7f486c0 [ 967.180406] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b [ 967.186374] CR2: 000000004822c0ac CR3: 00000001b19a2000 CR4: 00000000000006e0 [ 967.193770] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 967.201224] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 967.208692] Process hackbench (pid: 3351, threadinfo ffff8801a95aa000, task ffff8801a96b0000) [ 967.217607] Stack: [ 967.219711] 0000000000000000 0000000000000037 0000000200000001 ffffc90000a1107c [ 967.227296] <0> ffff8801a95abe00 0000000000000001 0000000000000001 0000000000000037 [ 967.235333] <0> ffff8801a95abdf0 ffffffff810c0c20 0000000200a14f30 ffff8801a95abe40 [ 967.243532] Call Trace: [ 967.246103] [] do_perf_swcounter_event+0xde/0xec [ 967.252635] [] perf_tpcounter_event+0x79/0x7b [ 967.258957] [] ftrace_profile_sched_switch+0xc0/0xcb [ 967.265791] [] schedule+0x429/0x4c4 [ 967.271156] [] int_careful+0xd/0x14 Reported-by: Ingo Molnar Signed-off-by: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <1251472247.17617.74.camel@laptop> Signed-off-by: Ingo Molnar

modules: Fix build error in the !CONFIG_KALLSYMS case

2009-08-29T05:35:00Z

> James Bottomley (1): > module: workaround duplicate section names -tip testing found that this patch breaks the build on x86 if CONFIG_KALLSYMS is disabled: kernel/module.c: In function ‘load_module’: kernel/module.c:2367: error: ‘struct module’ has no member named ‘sect_attrs’ distcc[8269] ERROR: compile kernel/module.c on ph/32 failed make[1]: *** [kernel/module.o] Error 1 make: *** [kernel] Error 2 make: *** Waiting for unfinished jobs.... Commit 1b364bf misses the fact that section attributes are only built and dealt with if kallsyms is enabled. The patch below fixes this. ( note, technically speaking this should depend on CONFIG_SYSFS as well but this patch is correct too and keeps the #ifdef less intrusive - in the KALLSYMS && !SYSFS case the code is a NOP. ) Signed-off-by: Ingo Molnar [ Replaced patch with a slightly cleaner variation by James Bottomley ] Signed-off-by: Linus Torvalds

perf_counters: Increase paranoia level

2009-08-28T11:44:53Z

Per-cpu counters are an ASLR information leak as they show the execution other tasks do. Increase the paranoia level to 1, which disallows per-cpu counters. (they still allow counting/profiling of own tasks - and admin can profile everything.) Acked-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar

module: workaround duplicate section names

2009-08-27T19:33:19Z

The root cause is a duplicate section name (.text); is this legal? [ Amerigo Wang: "AFAIK, yes." ] However, there's a problem with commit 6d76013381ed28979cd122eb4b249a88b5e384fa in that if you fail to allocate a mod->sect_attrs (in this case it's null because of the duplication), it still gets used without checking in add_notes_attrs() This should fix it [ This patch leaves other problems, particularly the sections directory, but recent parisc toolchains seem to produce these modules and this prevents a crash and is a minimal change -- RR ] Signed-off-by: James Bottomley Signed-off-by: Rusty Russell Tested-by: Helge Deller Signed-off-by: Linus Torvalds

module: fix BUG_ON() for powerpc (and other function descriptor archs)

2009-08-27T19:33:19Z

The rarely-used symbol_put_addr() needs to use dereference_function_descriptor on powerpc. Reported-by: Paul Mackerras Signed-off-by: Rusty Russell

clone(): fix race between copy_process() and de_thread()

2009-08-27T03:06:52Z

Spotted by Hiroshi Shimamoto who also provided the test-case below. copy_process() uses signal->count as a reference counter, but it is not. This test case #include #include #include #include #include #include void *null_thread(void *p) { for (;;) sleep(1); return NULL; } void *exec_thread(void *p) { execl("/bin/true", "/bin/true", NULL); return null_thread(p); } int main(int argc, char **argv) { for (;;) { pid_t pid; int ret, status; pid = fork(); if (pid < 0) break; if (!pid) { pthread_t tid; pthread_create(&tid, NULL, exec_thread, NULL); for (;;) pthread_create(&tid, NULL, null_thread, NULL); } do { ret = waitpid(pid, &status, 0); } while (ret == -1 && errno == EINTR); } return 0; } quickly creates an unkillable task. If copy_process(CLONE_THREAD) races with de_thread() copy_signal()->atomic(signal->count) breaks the signal->notify_count logic, and the execing thread can hang forever in kernel space. Change copy_process() to increment count/live only when we know for sure we can't fail. In this case the forked thread will take care of its reference to signal correctly. If copy_process() fails, check CLONE_THREAD flag. If it it set - do nothing, the counters were not changed and current belongs to the same thread group. If it is not set, ->signal must be released in any case (and ->count must be == 1), the forked child is the only thread in the thread group. We need more cleanups here, in particular signal->count should not be used by de_thread/__exit_signal at all. This patch only fixes the bug. Reported-by: Hiroshi Shimamoto Tested-by: Hiroshi Shimamoto Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Cc: KAMEZAWA Hiroyuki Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds