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Groups > linux.kernel > #1375167
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 4.4 009/210] x86/entry/compat: Keep TS_COMPAT set during signal delivery |
| Date | 2016-04-10 22:10 +0200 |
| Message-ID | <rmtQf-22e-39@gated-at.bofh.it> (permalink) |
| References | <rmsKu-Wx-25@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Lutomirski <luto@kernel.org>
commit 4e79e182b419172e35936a47f098509092d69817 upstream.
Signal delivery needs to know the sign of an interrupted syscall's
return value in order to detect -ERESTART variants. Normally this
works independently of bitness because syscalls internally return
long. Under ptrace, however, this can break, and syscall_get_error
is supposed to sign-extend regs->ax if needed.
We were clearing TS_COMPAT too early, though, and this prevented
sign extension, which subtly broke syscall restart under ptrace.
Reported-by: Robert O'Callahan <robert@ocallahan.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c5c46f59e4e7 ("x86/entry: Add new, comprehensible entry and exit handlers written in C")
Link: http://lkml.kernel.org/r/cbce3cf545522f64eb37f5478cb59746230db3b5.1455142412.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/entry/common.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -268,6 +268,7 @@ static void exit_to_usermode_loop(struct
/* Called with IRQs disabled. */
__visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
{
+ struct thread_info *ti = pt_regs_to_thread_info(regs);
u32 cached_flags;
if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled()))
@@ -275,12 +276,22 @@ __visible inline void prepare_exit_to_us
lockdep_sys_exit();
- cached_flags =
- READ_ONCE(pt_regs_to_thread_info(regs)->flags);
+ cached_flags = READ_ONCE(ti->flags);
if (unlikely(cached_flags & EXIT_TO_USERMODE_LOOP_FLAGS))
exit_to_usermode_loop(regs, cached_flags);
+#ifdef CONFIG_COMPAT
+ /*
+ * Compat syscalls set TS_COMPAT. Make sure we clear it before
+ * returning to user mode. We need to clear it *after* signal
+ * handling, because syscall restart has a fixup for compat
+ * syscalls. The fixup is exercised by the ptrace_syscall_32
+ * selftest.
+ */
+ ti->status &= ~TS_COMPAT;
+#endif
+
user_enter();
}
@@ -332,14 +343,6 @@ __visible inline void syscall_return_slo
if (unlikely(cached_flags & SYSCALL_EXIT_WORK_FLAGS))
syscall_slow_exit_work(regs, cached_flags);
-#ifdef CONFIG_COMPAT
- /*
- * Compat syscalls set TS_COMPAT. Make sure we clear it before
- * returning to user mode.
- */
- ti->status &= ~TS_COMPAT;
-#endif
-
local_irq_disable();
prepare_exit_to_usermode(regs);
}
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[PATCH 4.4 000/210] 4.4.7-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 025/210] EDAC/sb_edac: Fix computation of channel address Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 043/210] scsi: storvsc: fix SRB_STATUS_ABORTED handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 006/210] mmc: sh_mmcif: Correct TX DMA channel allocation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 007/210] x86/microcode/intel: Make early loader look for builtin microcode too Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 026/210] EDAC, amd64_edac: Shift wrapping issue in f1x_get_norm_dct_addr() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 016/210] KVM: VMX: avoid guest hang on invalid invvpid instruction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 094/210] staging: comedi: ni_mio_common: fix the ni_write[blw]() functions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 009/210] x86/entry/compat: Keep TS_COMPAT set during signal delivery Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 096/210] net: irda: Fix use-after-free in irtty_open() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 092/210] staging: comedi: ni_tiocmd: change mistaken use of start_src for start_arg Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 085/210] tpm_crb: tpm2_shutdown() must be called before tpm_chip_unregister() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 024/210] sched/preempt, sh: kmap_coherent relies on disabled preemption Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 042/210] sd: Fix discard granularity when LBPRZ=1 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 077/210] crypto: ccp - memset request context to zero during import Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 053/210] usb: hub: fix a typo in hub_port_init() leading to wrong logic Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 008/210] x86/microcode: Untangle from BLK_DEV_INITRD Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 051/210] dm: fix rq_end_stats() NULL pointer in dm_requeue_original_request() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 048/210] dm: fix excessive dm-mq context switching Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 076/210] crypto: ccp - Dont assume export/import areas are aligned Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 029/210] s390/pci: enforce fmb page boundary rule Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 091/210] HID: fix hid_ignore_special_drivers module parameter Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 022/210] Thermal: Ignore invalid trip points Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 090/210] HID: multitouch: force retrieving of Win8 signature blob Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 047/210] dm snapshot: disallow the COW and origin devices from being identical Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 044/210] be2iscsi: set the boot_kset pointer to NULL in case of failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:10 +0200
[PATCH 4.4 018/210] perf/core: Fix perf_sched_count derailment Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 001/210] s390/cpumf: Fix lpp detection Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 011/210] x86/PCI: Mark Broadwell-EP Home Agent & PCU as having non-compliant BARs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 019/210] perf tools: Dont stop PMU parsing on alias parse error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 014/210] KVM: fix spin_lock_init order on x86 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 017/210] KVM: VMX: fix nested vpid for old KVM guests Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 021/210] perf tools: Fix python extension build Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 012/210] KVM: x86: fix missed hardware breakpoints Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 004/210] ASoC: samsung: pass DMA channels as pointers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 010/210] perf/x86/intel: Add definition for PT PMI bit Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 015/210] KVM: VMX: avoid guest hang on invalid invept instruction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 005/210] mmc: sh_mmcif: rework dma channel handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 020/210] perf tools: Fix checking asprintf return value Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 002/210] regulator: core: avoid unused variable warning Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:20 +0200
[PATCH 4.4 028/210] s390/cpumf: add missing lpp magic initialization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 182/210] clk: rockchip: add hclk_cpubus to the list of rk3188 critical clocks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 170/210] kbuild/mkspec: fix grub2 installkernel issue Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 069/210] ALSA: usb-audio: Minor code cleanup in create_fixed_stream_quirk() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 073/210] Bluetooth: btusb: Add a new AR3012 ID 13d3:3472 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 188/210] iser-target: Rework connection termination Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 178/210] clk: rockchip: rk3368: fix cpuclk mux bit of big cpu-cluster Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:40 +0200
[PATCH 4.4 037/210] x86/mm: TLB_REMOTE_SEND_IPI should count pages Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-10 22:50 +0200
Re: [PATCH 4.4 159/210] drm/radeon: disable runtime pm on PX laptops without dGPU power control Michel Dänzer <michel@daenzer.net> - 2016-04-11 04:40 +0200
Re: [PATCH 4.4 159/210] drm/radeon: disable runtime pm on PX laptops without dGPU power control Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-12 16:20 +0200
Re: [PATCH 4.4 159/210] drm/radeon: disable runtime pm on PX laptops without dGPU power control Michel Dänzer <michel@daenzer.net> - 2016-04-13 06:00 +0200
Re: [PATCH 4.4 159/210] drm/radeon: disable runtime pm on PX laptops without dGPU power control Michel Dänzer <michel@daenzer.net> - 2016-04-14 04:50 +0200
Re: [PATCH 4.4 159/210] drm/radeon: disable runtime pm on PX laptops without dGPU power control Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-14 16:30 +0200
Re: [PATCH 4.4 000/210] 4.4.7-stable review Guenter Roeck <linux@roeck-us.net> - 2016-04-11 05:20 +0200
Re: [PATCH 4.4 000/210] 4.4.7-stable review shuahkh <shuahkh@osg.sisa.samsung.com> - 2016-04-11 19:30 +0200
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