From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Vince Weaver <vincent.weaver@maine.edu>,
Oleg Nesterov <oleg@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@kernel.org>
Subject: [ 04/13] hw_breakpoint: Use cpu_possible_mask in {reserve,release}_bp_slot()
Date: Mon, 1 Jul 2013 13:10:23 -0700 [thread overview]
Message-ID: <20130701200523.613925919@linuxfoundation.org> (raw)
In-Reply-To: <20130701200523.096669485@linuxfoundation.org>
3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Oleg Nesterov <oleg@redhat.com>
commit c790b0ad23f427c7522ffed264706238c57c007e upstream.
fetch_bp_busy_slots() and toggle_bp_slot() use
for_each_online_cpu(), this is obviously wrong wrt cpu_up() or
cpu_down(), we can over/under account the per-cpu numbers.
For example:
# echo 0 >> /sys/devices/system/cpu/cpu1/online
# perf record -e mem:0x10 -p 1 &
# echo 1 >> /sys/devices/system/cpu/cpu1/online
# perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10 -C1 -a &
# taskset -p 0x2 1
triggers the same WARN_ONCE("Can't find any breakpoint slot") in
arch_install_hw_breakpoint().
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20130620155009.GA6327@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/events/hw_breakpoint.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -147,7 +147,7 @@ fetch_bp_busy_slots(struct bp_busy_slots
return;
}
- for_each_online_cpu(cpu) {
+ for_each_possible_cpu(cpu) {
unsigned int nr;
nr = per_cpu(nr_cpu_bp_pinned[type], cpu);
@@ -233,7 +233,7 @@ toggle_bp_slot(struct perf_event *bp, bo
if (cpu >= 0) {
toggle_bp_task_slot(bp, cpu, enable, type, weight);
} else {
- for_each_online_cpu(cpu)
+ for_each_possible_cpu(cpu)
toggle_bp_task_slot(bp, cpu, enable, type, weight);
}
next prev parent reply other threads:[~2013-07-01 20:10 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-01 20:10 [ 00/13] 3.4.52-stable review Greg Kroah-Hartman
2013-07-01 20:10 ` [ 01/13] ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page Greg Kroah-Hartman
2013-07-01 20:10 ` [ 02/13] ARM: 7772/1: Fix missing flush_kernel_dcache_page() for noMMU Greg Kroah-Hartman
2013-07-01 20:10 ` [ 03/13] Bluetooth: Fix crash in l2cap_build_cmd() with small MTU Greg Kroah-Hartman
2013-07-01 20:10 ` Greg Kroah-Hartman [this message]
2013-07-01 20:10 ` [ 05/13] dlci: acquire rtnl_lock before calling __dev_get_by_name() Greg Kroah-Hartman
2013-07-01 20:10 ` [ 06/13] dlci: validate the net device in dlci_del() Greg Kroah-Hartman
2013-07-01 20:10 ` [ 07/13] net/tg3: Avoid delay during MMIO access Greg Kroah-Hartman
2013-07-02 9:06 ` Luis Henriques
2013-07-03 17:53 ` Greg Kroah-Hartman
2013-07-01 20:10 ` [ 08/13] perf: Disable monitoring on setuid processes for regular users Greg Kroah-Hartman
2013-07-01 20:10 ` [ 09/13] UBIFS: prepare to fix a horrid bug Greg Kroah-Hartman
2013-07-01 20:10 ` [ 10/13] UBIFS: " Greg Kroah-Hartman
2013-07-01 20:10 ` [ 11/13] pch_uart: fix a deadlock when pch_uart as console Greg Kroah-Hartman
2013-07-01 20:10 ` [ 12/13] perf: Fix perf mmap bugs Greg Kroah-Hartman
2013-07-01 20:10 ` [ 13/13] perf: Fix mmap() accounting hole Greg Kroah-Hartman
2013-07-02 14:39 ` [ 00/13] 3.4.52-stable review Guenter Roeck
2013-07-02 18:55 ` Greg Kroah-Hartman
2013-07-02 21:25 ` Guenter Roeck
2013-07-02 18:47 ` Shuah Khan
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