diff options
| author | Kevin Hilman <khilman@linaro.org> | 2015-05-22 14:30:13 -0700 |
|---|---|---|
| committer | Kevin Hilman <khilman@linaro.org> | 2015-05-22 14:30:13 -0700 |
| commit | e49d192fe7dcdc7bc46987f9981dc90f61e5f28c (patch) | |
| tree | 84579e5de62f4d67d65203450d0e0268e1e47f2f /kernel/ptrace.c | |
| parent | a61d3b775855a1d67d97ca0aa389489cb8a9320d (diff) | |
| parent | 51af817611f2c0987030d024f24fc7ea95dd33e6 (diff) | |
Merge branch 'linux-3.18.y' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into linux-linaro-lsk-v3.18lsk-v3.18-15.05
* 'linux-3.18.y' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable: (222 commits)
Linux 3.18.14
Drivers: hv: vmbus: Don't wait after requesting offers
hfsplus: don't store special "osx" xattr prefix on-disk
drm/radeon: check new address before removing old one
drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5
drm/radeon: adjust pll when audio is not enabled
3w-sas: fix command completion race
3w-9xxx: fix command completion race
3w-xxxx: fix command completion race
ext4: move check under lock scope to close a race.
ext4: fix data corruption caused by unwritten and delayed extents
uas: Set max_sectors_240 quirk for ASM1053 devices
uas: Add US_FL_MAX_SECTORS_240 flag
uas: Allow uas_use_uas_driver to return usb-storage flags
rbd: end I/O the entire obj_request on error
tty/serial: at91: maxburst was missing for dma transfers
ACPI / SBS: Enable battery manager when present
btrfs: unlock i_mutex after attempting to delete subvolume during send
ASoC: rt5677: fixed wrong DMIC ref clock
ASoC: dapm: Enable autodisable on SOC_DAPM_SINGLE_TLV_AUTODISABLE
...
Diffstat (limited to 'kernel/ptrace.c')
| -rw-r--r-- | kernel/ptrace.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 54e75226c2c4..dcd968232d42 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -714,6 +714,8 @@ static int ptrace_peek_siginfo(struct task_struct *child, static int ptrace_resume(struct task_struct *child, long request, unsigned long data) { + bool need_siglock; + if (!valid_signal(data)) return -EIO; @@ -741,8 +743,26 @@ static int ptrace_resume(struct task_struct *child, long request, user_disable_single_step(child); } + /* + * Change ->exit_code and ->state under siglock to avoid the race + * with wait_task_stopped() in between; a non-zero ->exit_code will + * wrongly look like another report from tracee. + * + * Note that we need siglock even if ->exit_code == data and/or this + * status was not reported yet, the new status must not be cleared by + * wait_task_stopped() after resume. + * + * If data == 0 we do not care if wait_task_stopped() reports the old + * status and clears the code too; this can't race with the tracee, it + * takes siglock after resume. + */ + need_siglock = data && !thread_group_empty(current); + if (need_siglock) + spin_lock_irq(&child->sighand->siglock); child->exit_code = data; wake_up_state(child, __TASK_TRACED); + if (need_siglock) + spin_unlock_irq(&child->sighand->siglock); return 0; } |