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alistair23-linux/arch/sparc/kernel
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Rob Gardner fc290a114f sparc64: Prevent perf from running during super critical sections 
This fixes another cause of random segfaults and bus errors that may
occur while running perf with the callgraph option.

Critical sections beginning with spin_lock_irqsave() raise the interrupt
level to PIL_NORMAL_MAX (14) and intentionally do not block performance
counter interrupts, which arrive at PIL_NMI (15).

But some sections of code are "super critical" with respect to perf
because the perf_callchain_user() path accesses user space and may cause
TLB activity as well as faults as it unwinds the user stack.

One particular critical section occurs in switch_mm:

        spin_lock_irqsave(&mm->context.lock, flags);
        ...
        load_secondary_context(mm);
        tsb_context_switch(mm);
        ...
        spin_unlock_irqrestore(&mm->context.lock, flags);

If a perf interrupt arrives in between load_secondary_context() and
tsb_context_switch(), then perf_callchain_user() could execute with
the context ID of one process, but with an active TSB for a different
process. When the user stack is accessed, it is very likely to
incur a TLB miss, since the h/w context ID has been changed. The TLB
will then be reloaded with a translation from the TSB for one process,
but using a context ID for another process. This exposes memory from
one process to another, and since it is a mapping for stack memory,
this usually causes the new process to crash quickly.

This super critical section needs more protection than is provided
by spin_lock_irqsave() since perf interrupts must not be allowed in.

Since __tsb_context_switch already goes through the trouble of
disabling interrupts completely, we fix this by moving the secondary
context load down into this better protected region.

Orabug: 25577560

Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 		2017-07-18 11:25:52 -07:00
..
.gitignore
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Makefile sparc64:Support User Probes for sparc 2016-12-11 18:01:51 -08:00
apc.c sparc: kernel: apc: make of_device_ids const 2017-06-25 13:39:02 -07:00
asm-offsets.c sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
audit.c sparc: Convert naked unsigned uses to unsigned int 2016-03-20 21:28:58 -07:00
auxio_32.c sparc32: fix sparse warning in auxio_32.c 2014-05-18 19:01:27 -07:00
auxio_64.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
btext.c sparc64: fix sparse warning in btext.c 2014-05-18 19:01:30 -07:00
central.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
cherrs.S sparc64: Fix bootup regressions on some Kconfig combinations. 2016-04-27 17:27:37 -04:00
chmc.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
compat_audit.c sparc: Convert naked unsigned uses to unsigned int 2016-03-20 21:28:58 -07:00
cpu.c sparc64: recognize and support Sonoma CPU type 2016-04-21 16:43:47 -04:00
cpumap.c sparc64: recognize and support Sonoma CPU type 2016-04-21 16:43:47 -04:00
cpumap.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
devices.c sparc32: drop tadpole specific code 2014-05-18 19:01:29 -07:00
dma.c sparc: remove several unnecessary module.h include instances 2011-10-31 19:30:54 -04:00
ds.c sparc64: Fix build warnings with gcc 7. 2017-06-01 09:42:46 -07:00
dtlb_miss.S
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dtlb_prot.S sparc: Don't leak context bits into thread->fault_address 2016-07-27 17:50:26 -07:00
ebus.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
entry.S sparc: move exports to definitions 2016-08-07 23:55:43 -04:00
entry.h sparc: Resolve conflict between sparc v9 and M7 on usage of bit 9 of TTE 2015-05-31 22:15:01 -07:00
etrap_32.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
etrap_64.S sparc64: clear syscall_noerror on the entry to syscall, not on the exit 2012-10-14 19:26:52 -04:00
fpu_traps.S sparc64: Fix bootup regressions on some Kconfig combinations. 2016-04-27 17:27:37 -04:00
ftrace.c sparc/ftrace: Fix ftrace graph time measurement 2017-05-17 12:07:47 -07:00
getsetcc.S
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head_32.S sparc32: kill __ret_efault() 2017-03-28 18:24:00 -04:00
head_64.S sparc64: fix fault handling in NGbzero.S and GENbzero.S 2017-05-09 12:16:25 -07:00
helpers.S sparc: move exports to definitions 2016-08-07 23:55:43 -04:00
hvapi.c sparc64: Add ATU (new IOMMU) support 2016-11-18 11:16:59 -08:00
hvcalls.S sparc: move exports to definitions 2016-08-07 23:55:43 -04:00
hvtramp.S sparc64: Fix register corruption in top-most kernel stack frame during boot. 2014-10-24 09:52:49 -07:00
idprom.c net: Add eth_platform_get_mac_address() helper. 2016-01-06 16:31:56 -05:00
iommu.c sparc: remove arch specific dma_supported implementations 2017-06-28 06:54:39 -07:00
iommu_common.h sparc: implement ->mapping_error 2017-06-28 06:54:32 -07:00
ioport.c sparc: remove arch specific dma_supported implementations 2017-06-28 06:54:39 -07:00
irq.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
irq_32.c sparc32: off by ones in BUG_ON() 2016-07-27 22:53:17 -07:00
irq_64.c arch/sparc: support NR_CPUS = 4096 2017-06-06 16:41:47 -04:00
itlb_miss.S
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ivec.S
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jump_label.c jump_label: Reorder hotplug lock and jump_label_lock 2017-05-26 10:10:45 +02:00
kernel.h sparc64: initialize time early 2017-06-12 15:44:03 -07:00
kgdb_32.c sparc32: use proper prototype for trapbase 2016-05-20 17:55:41 -07:00
kgdb_64.c sparc64: fix sparse warning in kgdb_64.c 2014-05-18 19:01:34 -07:00
kprobes.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
kstack.h
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ktlb.S sparc: Don't leak context bits into thread->fault_address 2016-07-27 17:50:26 -07:00
ldc.c sparc64: skip handshake for LDC channels in RAW mode 2017-06-25 13:43:12 -07:00
led.c sparc: use memdup_user_nul in sun4m LED driver 2017-05-09 12:16:25 -07:00
leon_kernel.c sparc: leon: Fix a retry loop in leon_init_timers() 2016-12-11 18:15:49 -08:00
leon_pci.c PCI: Cleanup control flow 2015-03-19 10:17:22 -05:00
leon_pci_grpci1.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
leon_pci_grpci2.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
leon_pmc.c sparc32: fix sparse warnings in leon_pmc.c 2014-04-29 01:12:27 -04:00
leon_smp.c sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
mdesc.c mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic 2017-07-12 16:26:03 -07:00
misctrap.S arch/sparc: Avoid DCTI Couples 2017-03-27 21:51:40 -07:00
module.c mm: vmalloc: pass additional vm_flags to __vmalloc_node_range() 2015-02-13 21:21:42 -08:00
nmi.c kernel/watchdog: introduce arch_touch_nmi_watchdog() 2017-07-12 16:26:02 -07:00
of_device_32.c sparc32: rename sparc_irq_config to sparc_config 2012-04-15 10:28:49 -07:00
of_device_64.c devicetree: add helper inline for retrieving a node's full name 2012-07-06 07:16:34 -05:00
of_device_common.c sparc: fix sparse warnings in of_device_common.c 2014-04-29 01:12:27 -04:00
of_device_common.h
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pci.c PCI: Add BAR index argument to pci_mmap_page_range() 2017-04-20 08:47:47 -05:00
pci_common.c sparc/PCI: Add mem64 resource parsing for root bus 2015-10-29 17:35:46 -05:00
pci_fire.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
pci_impl.h sparc/PCI: Add mem64 resource parsing for root bus 2015-10-29 17:35:46 -05:00
pci_msi.c PCI/MSI: Rename mask/unmask_msi_irq treewide 2014-11-23 13:01:45 +01:00
pci_psycho.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
pci_sabre.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
pci_schizo.c Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
pci_sun4v.c SPARC64: Fix sun4v DMA panic 2017-07-12 08:13:04 -07:00
pci_sun4v.h sparc64: Enable sun4v dma ops to use IOMMU v2 APIs 2016-11-18 11:17:00 -08:00
pci_sun4v_asm.S sparc64: Enable sun4v dma ops to use IOMMU v2 APIs 2016-11-18 11:17:00 -08:00
pcic.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pcr.c sparc: perf: Add support M7 processor 2015-03-19 18:54:49 -07:00
perf_event.c perf core: Add a 'nr' field to perf_event_callchain_context 2016-05-16 23:11:51 -03:00
pmc.c sparc: kernel: pmc: make of_device_ids const. 2017-07-03 02:53:07 -07:00
power.c sparc: kernel: use builtin_platform_driver 2016-12-11 18:15:48 -08:00
process_32.c arch: remove unused macro/function thread_saved_pc() 2017-06-28 16:13:57 -07:00
process_64.c arch: remove unused macro/function thread_saved_pc() 2017-06-28 16:13:57 -07:00
prom.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
prom_32.c sparc: remove several unnecessary module.h include instances 2011-10-31 19:30:54 -04:00
prom_64.c sparc64: fix typo in property 2017-06-25 22:01:11 -04:00
prom_common.c of: Fix locking vs. interrupts 2013-06-13 22:12:14 +01:00
prom_irqtrans.c sparc: Remove unnecessary semicolons 2011-06-07 16:06:34 -07:00
psycho_common.c sparc: Remove unnecessary semicolons 2011-06-07 16:06:34 -07:00
psycho_common.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
ptrace_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ptrace_64.c sparc64: Fill in rest of HAVE_REGS_AND_STACK_ACCESS_API 2017-04-23 17:15:51 -07:00
reboot.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
rtrap_32.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
rtrap_64.S arch/sparc: Avoid DCTI Couples 2017-03-27 21:51:40 -07:00
sbus.c sparc: kernel/sbus.c: fix memory leakage 2013-01-21 14:33:00 -08:00
setup_32.c sparc: Remove redundant tests in boot_flags_init(). 2017-05-03 08:28:48 -07:00
setup_64.c sparc64: initialize time early 2017-06-12 15:44:03 -07:00
signal32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
signal_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
signal_64.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sigutil.h sparc: Allow handling signals when stack is corrupted. 2011-08-20 17:14:54 -07:00
sigutil_32.c sparc: Harden signal return frame checks. 2016-05-29 11:24:05 -07:00
sigutil_64.c sparc: Harden signal return frame checks. 2016-05-29 11:24:05 -07:00
smp_32.c cpu/hotplug: Remove CPU_STARTING and CPU_DYING notifier 2016-09-06 18:30:19 +02:00
smp_64.c sparc64: Measure receiver forward progress to avoid send mondo timeout 2017-07-14 11:18:02 -07:00
sparc_ksyms.c sparc: move exports to definitions 2016-08-07 23:55:43 -04:00
spiterrs.S arch/sparc: Avoid DCTI Couples 2017-03-27 21:51:40 -07:00
sstate.c sparc: Fixed typo in sstate.c. Replaced panicing with panicking 2017-01-16 22:31:51 -05:00
stacktrace.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
starfire.c arch: sparc: kernel: starfire.c: Remove unused function 2015-03-01 21:33:58 -08:00
sun4d_irq.c sparc/irq: Use helper irq_data_get_irq_handler_data() 2015-07-31 22:20:05 +02:00
sun4d_smp.c sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
sun4m_irq.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
sun4m_smp.c sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
sun4v_ivec.S sparc64: Measure receiver forward progress to avoid send mondo timeout 2017-07-14 11:18:02 -07:00
sun4v_tlb_miss.S arch/sparc: Avoid DCTI Couples 2017-03-27 21:51:40 -07:00
sys32.S sparc: Hook up renameat2 syscall. 2014-07-21 22:27:56 -07:00
sys_sparc32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sys_sparc_32.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
sys_sparc_64.c mm: larger stack guard gap, between vmas 2017-06-19 21:50:20 +08:00
syscalls.S sparc: Fix system call tracing register handling. 2016-01-21 16:06:00 -08:00
sysfs.c sparc/sysfs: Replace racy task affinity logic 2017-04-15 12:20:54 +02:00
systbls.h sparc64: fix sparse warnings in sys_sparc32.c 2014-05-18 19:01:31 -07:00
systbls_32.S sparc: Update syscall tables. 2017-04-23 18:28:55 -07:00
systbls_64.S sparc: Update syscall tables. 2017-04-23 18:28:55 -07:00
time_32.c sparc/time: make of_device_ids const 2017-06-15 08:25:19 -07:00
time_64.c sparc64: fix typo in property 2017-06-25 22:01:11 -04:00
trampoline_32.S sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
trampoline_64.S sparc64: Fix register corruption in top-most kernel stack frame during boot. 2014-10-24 09:52:49 -07:00
traps_32.c sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
traps_64.c sparc64: Measure receiver forward progress to avoid send mondo timeout 2017-07-14 11:18:02 -07:00
tsb.S sparc64: Prevent perf from running during super critical sections 2017-07-18 11:25:52 -07:00
ttable_32.S sparc32: move trap table to a separate file 2012-05-19 23:27:25 -07:00
ttable_64.S sparc64: delete old wrap code 2017-06-06 13:45:29 -07:00
una_asm_32.S
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una_asm_64.S
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unaligned_32.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
unaligned_64.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
uprobes.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
urtt_fill.S arch/sparc: Avoid DCTI Couples 2017-03-27 21:51:40 -07:00
utrap.S sparc64: Fix bootup regressions on some Kconfig combinations. 2016-04-27 17:27:37 -04:00
vio.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next 2017-07-08 12:14:14 -07:00
viohs.c sparc64: skip handshake for LDC channels in RAW mode 2017-06-25 13:43:12 -07:00
visemul.c scripts/spelling.txt: add "partiton" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
vmlinux.lds.S sparc64: add hot-patched and inlined get_tick() 2017-06-12 15:44:03 -07:00
windows.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
winfixup.S arch/sparc: Avoid DCTI Couples 2017-03-27 21:51:40 -07:00
wof.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
wuf.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00