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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Heiko Carstens <hca@linux.ibm.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-s390@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 25/31] s390: always clear kernel stack backchain before calling functions
Date: Wed, 30 Dec 2020 08:03:07 -0500	[thread overview]
Message-ID: <20201230130314.3636961-25-sashal@kernel.org> (raw)
In-Reply-To: <20201230130314.3636961-1-sashal@kernel.org>

From: Heiko Carstens <hca@linux.ibm.com>

[ Upstream commit 9365965db0c7ca7fc81eee27c21d8522d7102c32 ]

Clear the kernel stack backchain before potentially calling the
lockdep trace_hardirqs_off/on functions. Without this walking the
kernel backchain, e.g. during a panic, might stop too early.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/s390/kernel/entry.S | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 92beb14446449..9bdf3dbd04247 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -390,6 +390,7 @@ ENTRY(system_call)
 	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
 	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
 	stg	%r14,__PT_FLAGS(%r11)
+	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	ENABLE_INTS
 .Lsysc_do_svc:
 	# clear user controlled register to prevent speculative use
@@ -406,7 +407,6 @@ ENTRY(system_call)
 	jnl	.Lsysc_nr_ok
 	slag	%r8,%r1,3
 .Lsysc_nr_ok:
-	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	stg	%r2,__PT_ORIG_GPR2(%r11)
 	stg	%r7,STACK_FRAME_OVERHEAD(%r15)
 	lg	%r9,0(%r8,%r10)			# get system call add.
@@ -696,8 +696,8 @@ ENTRY(pgm_check_handler)
 	mvc	__THREAD_per_address(8,%r14),__LC_PER_ADDRESS
 	mvc	__THREAD_per_cause(2,%r14),__LC_PER_CODE
 	mvc	__THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
-6:	RESTORE_SM_CLEAR_PER
-	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+6:	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+	RESTORE_SM_CLEAR_PER
 	larl	%r1,pgm_check_table
 	llgh	%r10,__PT_INT_CODE+2(%r11)
 	nill	%r10,0x007f
@@ -718,8 +718,8 @@ ENTRY(pgm_check_handler)
 # PER event in supervisor state, must be kprobes
 #
 .Lpgm_kprobe:
-	RESTORE_SM_CLEAR_PER
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+	RESTORE_SM_CLEAR_PER
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	brasl	%r14,do_per_trap
 	j	.Lpgm_return
@@ -761,10 +761,10 @@ ENTRY(io_int_handler)
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
 	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
+	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
 	jo	.Lio_restore
 	TRACE_IRQS_OFF
-	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 .Lio_loop:
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	lghi	%r3,IO_INTERRUPT
@@ -964,10 +964,10 @@ ENTRY(ext_int_handler)
 	mvc	__PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
 	mvc	__PT_INT_PARM_LONG(8,%r11),0(%r1)
 	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
+	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	TSTMSK	__LC_CPU_FLAGS,_CIF_IGNORE_IRQ
 	jo	.Lio_restore
 	TRACE_IRQS_OFF
-	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	lghi	%r3,EXT_INTERRUPT
 	brasl	%r14,do_IRQ
-- 
2.27.0


  parent reply	other threads:[~2020-12-30 13:10 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-30 13:02 [PATCH AUTOSEL 5.10 01/31] ARM: 9014/2: Replace string mem* functions for KASan Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 02/31] rtc: sun6i: Fix memleak in sun6i_rtc_clk_init Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 03/31] module: set MODULE_STATE_GOING state when a module fails to load Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 04/31] quota: Don't overflow quota file offsets Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 05/31] rtc: pl031: fix resource leak in pl031_probe Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 06/31] powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe() Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 07/31] i3c master: fix missing destroy_workqueue() on error in i3c_master_register Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 08/31] reiserfs: add check for an invalid ih_entry_count Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 09/31] NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 10/31] f2fs: Handle casefolding with Encryption Sasha Levin
2020-12-30 18:01   ` [f2fs-dev] " Eric Biggers
2021-01-04 14:20     ` Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 11/31] f2fs: avoid race condition for shrinker count Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 12/31] f2fs: fix race of pending_pages in decompression Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 13/31] module: delay kobject uevent until after module init call Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 14/31] powerpc/64: irq replay remove decrementer overflow check Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 15/31] f2fs: fix shift-out-of-bounds in sanity_check_raw_super() Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 16/31] fs/namespace.c: WARN if mnt_count has become negative Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 17/31] watchdog: rti-wdt: fix reference leak in rti_wdt_probe Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 18/31] um: random: Register random as hwrng-core device Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 19/31] um: ubd: Submit all data segments atomically Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 20/31] um: allocate a guard page to helper threads Sasha Levin
2020-12-30 14:48   ` Johannes Berg
2021-01-04 14:21     ` Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 21/31] NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 22/31] ceph: fix inode refcount leak when ceph_fill_inode on non-I_NEW inode fails Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 23/31] drm/amd/display: updated wm table for Renoir Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 24/31] tick/sched: Remove bogus boot "safety" check Sasha Levin
2020-12-30 13:03 ` Sasha Levin [this message]
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 26/31] io_uring: remove racy overflow list fast checks Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 27/31] ext4: check for invalid block size early when mounting a file system Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 28/31] ALSA: pcm: Clear the full allocated memory at hw_params Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 29/31] dm verity: skip verity work if I/O error when system is shutting down Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 30/31] ext4: avoid s_mb_prefetch to be zero in individual scenarios Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 31/31] device-dax: Fix range release Sasha Levin
2020-12-30 14:18 ` [PATCH AUTOSEL 5.10 01/31] ARM: 9014/2: Replace string mem* functions for KASan Ahmad Fatoum
2021-01-04 14:29   ` Sasha Levin

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