Improve error handling when arming ftrace-based kprobes. Specifically, if
we fail to arm a ftrace-based kprobe, register_kprobe()/enable_kprobe()
should report an error instead of success. Previously, this has lead to
confusing situations where register_kprobe() would return 0 indicating
success, but the kprobe would not be functional if ftrace registration
during the kprobe arming process had failed. We should therefore take any
errors returned by ftrace into account and propagate this error so that we
do not register/enable kprobes that cannot be armed. This can happen if,
for example, register_ftrace_function() finds an IPMODIFY conflict (since
kprobe_ftrace_ops has this flag set) and returns an error. Such a conflict
is possible since livepatches also set the IPMODIFY flag for their ftrace_ops.
arm_all_kprobes() keeps its current behavior and attempts to arm all
kprobes. It returns the last encountered error and gives a warning if
not all probes could be armed.
This patch is based on Petr Mladek's original patchset (patches 2 and 3)
back in 2015, which improved kprobes error handling, found here:
https://lkml.org/lkml/2015/2/26/452
However, further work on this had been paused since then and the patches
were not upstreamed.
Based-on-patches-by: Petr Mladek <[email protected]>
Signed-off-by: Jessica Yu <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Anil S Keshavamurthy <[email protected]>
Cc: David S . Miller <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Joe Lawrence <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Miroslav Benes <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Pull perf/core fixes from Arnaldo Carvalho de Melo:
- perf_mmap overwrite mode fixes/overhaul, prep work to get 'perf top'
using it, making it bearable to use it in large core count systems
such as Knights Landing/Mill Intel systems (Kan Liang)
- s/390 now uses syscall.tbl, just like x86-64 to generate the syscall
table id -> string tables used by 'perf trace' (Hendrik Brueckner)
- Use strtoull() instead of home grown function (Andy Shevchenko)
- Synchronize kernel ABI headers, v4.16-rc1 (Ingo Molnar)
- Document missing 'perf data --force' option (Sangwon Hong)
- Add perf vendor JSON metrics for ARM Cortex-A53 Processor (William Cohen)
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Sync the following tooling headers with the latest kernel version:
tools/arch/powerpc/include/uapi/asm/kvm.h
tools/arch/x86/include/asm/cpufeatures.h
tools/include/uapi/drm/i915_drm.h
tools/include/uapi/linux/if_link.h
tools/include/uapi/linux/kvm.h
All the changes are new ABI additions which don't impact their use
in existing tooling.
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
On Intel test case trace+probe_libc_inet_pton.sh succeeds and the
output is:
[root@f27 perf]# ./perf trace --no-syscalls
-e probe_libc:inet_pton/max-stack=3/ ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.037 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.037/0.037/0.037/0.000 ms
0.000 probe_libc:inet_pton:(7fa40ac618a0))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
getaddrinfo (/usr/lib64/libc-2.26.so)
main (/usr/bin/ping)
The kernel stack unwinder is used, it is specified implicitly
as call-graph=fp (frame pointer).
On s390x only dwarf is available for stack unwinding. It is also
done in user space. This requires different parameter setup
and result checking for s390x and Intel.
This patch adds separate perf trace setup and result checking
for Intel and s390x. On s390x specify this command line to
get a call-graph and handle the different call graph result
checking:
[root@s35lp76 perf]# ./perf trace --no-syscalls
-e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.041 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.041/0.041/0.041/0.000 ms
0.000 probe_libc:inet_pton:(3ffb9942060))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
gaih_inet (inlined)
__GI_getaddrinfo (inlined)
main (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
_start (/usr/bin/ping)
[root@s35lp76 perf]#
Before:
[root@s8360047 perf]# ./perf test -vv 58
58: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 26349
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.079 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.079/0.079/0.079/0.000 ms
0.000 probe_libc:inet_pton:(3ff925c2060))
test child finished with -1
---- end ----
probe libc's inet_pton & backtrace it with ping: FAILED!
[root@s8360047 perf]#
After:
[root@s35lp76 perf]# ./perf test -vv 57
57: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 38708
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.038 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.038/0.038/0.038/0.000 ms
0.000 probe_libc:inet_pton:(3ff87342060))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
gaih_inet (inlined)
__GI_getaddrinfo (inlined)
main (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
_start (/usr/bin/ping)
test child finished with 0
---- end ----
probe libc's inet_pton & backtrace it with ping: Ok
[root@s35lp76 perf]#
On Intel the test case runs unchanged and succeeds.
Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Hendrik Brueckner <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
perf_top__mmap_read() has a severe performance issue in the Knights
Landing/Mill platform, when monitoring heavy load systems. It costs
several minutes to finish, which is unacceptable.
Currently, 'perf top' uses the non overwrite mode. For non overwrite
mode, it tries to read everything in the ringbuffer and doesn't pause
it. Once there are lots of samples delivered persistently, the
processing time could be very long. Also, the latest samples could be
lost when the ringbuffer is full.
For overwrite mode, it takes a snapshot for the system by pausing the
ringbuffer, which could significantly reduce the processing time. Also,
the overwrite mode always keep the latest samples. Considering the real
time requirement for 'perf top', the overwrite mode is more suitable for
it.
Actually, 'perf top' was overwrite mode. It is changed to non overwrite
mode since commit 93fc64f144 ("perf top: Switch to non overwrite
mode"). It's better to change it back to overwrite mode by default.
For the kernel which doesn't support overwrite mode, it will fall back
to non overwrite mode.
There would be some records lost in overwrite mode because of pausing
the ringbuffer. It has little impact for the accuracy of the snapshot
and can be tolerated.
For overwrite mode, unconditionally wait 100 ms before each snapshot. It
also reduces the overhead caused by pausing ringbuffer, especially on
light load system.
Signed-off-by: Kan Liang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Per-event overwrite term is not forbidden in 'perf top', which can bring
problems. Because 'perf top' only support non-overwrite mode now.
Add new rules and check regarding to overwrite term for 'perf top'.
- All events either have same per-event term or don't have per-event
mode setting. Otherwise, it will error out.
- Per-event overwrite term should be consistent as opts->overwrite.
If not, updating the opts->overwrite according to per-event term.
Make it possible to support either non-overwrite or overwrite mode.
The overwrite mode is forbidden now, which will be removed when the
overwrite mode is supported later.
Signed-off-by: Kan Liang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Renamed perf_top_overwrite_check to perf_top__overwrite_check, to follow existing convention ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Use the new perf_mmap__read_* interfaces for overwrite ringbuffer test.
Commiter notes:
Testing:
[root@seventh ~]# perf test -v backward
48: Read backward ring buffer :
--- start ---
test child forked, pid 8309
Using CPUID GenuineIntel-6-9E
mmap size 1052672B
mmap size 8192B
Finished reading overwrite ring buffer: rewind
test child finished with 0
---- end ----
Read backward ring buffer: Ok
[root@seventh ~]#
Signed-off-by: Kan Liang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Except for 'perf record', the other perf tools read events one by one
from the ring buffer using perf_mmap__read_forward(). But it only
supports non-overwrite mode.
Introduce perf_mmap__read_event() to support both non-overwrite and
overwrite mode.
Usage:
perf_mmap__read_init()
while(event = perf_mmap__read_event()) {
//process the event
perf_mmap__consume()
}
perf_mmap__read_done()
It cannot use perf_mmap__read_backward(). Because it always reads the
stale buffer which is already processed. Furthermore, the forward and
backward concepts have been removed. The perf_mmap__read_backward() will
be replaced and discarded later.
Signed-off-by: Kan Liang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
In perf_mmap__push(), the 'size' need to be recalculated, otherwise the
invalid data might be pushed to the record in overwrite mode.
The issue is introduced by commit 7fb4b407a1 ("perf mmap: Don't
discard prev in backward mode").
When the ring buffer is full in overwrite mode, backward_rb_find_range()
will be called to recalculate the 'start' and 'end'. The 'size' needs to
be recalculated accordingly.
Unconditionally recalculate the 'size', not just for full ring buffer in
overwrite mode. Because:
- There is no harmful to recalculate the 'size' for other cases.
- The code of calculating 'start' and 'end' will be factored out later.
The new function does not need to return 'size'.
Signed-off-by: Kan Liang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Fixes: 7fb4b407a1 ("perf mmap: Don't discard prev in backward mode")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Add JSON metrics for ARM Cortex-A53 Processor.
Unlike the Intel processors there isn't a script that automatically
generated these files. The patch was manually generated from the
documentation and the previous oprofile ARM Cortex ac53 event file patch
I made.
The relevant documentation is in the "12.9 Events" section of the ARM
Cortex A53 MPCore Processor Revision: r0p4 Technical Reference Manual.
The ARM Cortex A53 manual is available at:
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0500g/DDI0500G_cortex_a53_trm.pdf
Use that to look for additional information about the events.
Signed-off-by: William Cohen <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Added references provided by William Cohen ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Pull x86 fixes from Ingo Molnar:
"Misc fixes all across the map:
- /proc/kcore vsyscall related fixes
- LTO fix
- build warning fix
- CPU hotplug fix
- Kconfig NR_CPUS cleanups
- cpu_has() cleanups/robustification
- .gitignore fix
- memory-failure unmapping fix
- UV platform fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages
x86/error_inject: Make just_return_func() globally visible
x86/platform/UV: Fix GAM Range Table entries less than 1GB
x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore
x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU
x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally
vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
x86/Kconfig: Further simplify the NR_CPUS config
x86/Kconfig: Simplify NR_CPUS config
x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()"
x86/cpufeature: Update _static_cpu_has() to use all named variables
x86/cpufeature: Reindent _static_cpu_has()
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar:
"Here's the latest set of Spectre and PTI related fixes and updates:
Spectre:
- Add entry code register clearing to reduce the Spectre attack
surface
- Update the Spectre microcode blacklist
- Inline the KVM Spectre helpers to get close to v4.14 performance
again.
- Fix indirect_branch_prediction_barrier()
- Fix/improve Spectre related kernel messages
- Fix array_index_nospec_mask() asm constraint
- KVM: fix two MSR handling bugs
PTI:
- Fix a paranoid entry PTI CR3 handling bug
- Fix comments
objtool:
- Fix paranoid_entry() frame pointer warning
- Annotate WARN()-related UD2 as reachable
- Various fixes
- Add Add Peter Zijlstra as objtool co-maintainer
Misc:
- Various x86 entry code self-test fixes
- Improve/simplify entry code stack frame generation and handling
after recent heavy-handed PTI and Spectre changes. (There's two
more WIP improvements expected here.)
- Type fix for cache entries
There's also some low risk non-fix changes I've included in this
branch to reduce backporting conflicts:
- rename a confusing x86_cpu field name
- de-obfuscate the naming of single-TLB flushing primitives"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
x86/entry/64: Fix CR3 restore in paranoid_exit()
x86/cpu: Change type of x86_cache_size variable to unsigned int
x86/spectre: Fix an error message
x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping
selftests/x86/mpx: Fix incorrect bounds with old _sigfault
x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
x86/speculation: Add <asm/msr-index.h> dependency
nospec: Move array_index_nospec() parameter checking into separate macro
x86/speculation: Fix up array_index_nospec_mask() asm constraint
x86/debug: Use UD2 for WARN()
x86/debug, objtool: Annotate WARN()-related UD2 as reachable
objtool: Fix segfault in ignore_unreachable_insn()
selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c
selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
selftests/x86/pkeys: Remove unused functions
selftests/x86: Clean up and document sscanf() usage
selftests/x86: Fix vDSO selftest segfault for vsyscall=none
x86/entry/64: Remove the unused 'icebp' macro
...
Josh Poimboeuf noticed the following bug:
"The paranoid exit code only restores the saved CR3 when it switches back
to the user GS. However, even in the kernel GS case, it's possible that
it needs to restore a user CR3, if for example, the paranoid exception
occurred in the syscall exit path between SWITCH_TO_USER_CR3_STACK and
SWAPGS."
Josh also confirmed via targeted testing that it's possible to hit this bug.
Fix the bug by also restoring CR3 in the paranoid_exit_no_swapgs branch.
The reason we haven't seen this bug reported by users yet is probably because
"paranoid" entry points are limited to the following cases:
idtentry double_fault do_double_fault has_error_code=1 paranoid=2
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
idtentry machine_check do_mce has_error_code=0 paranoid=1
Amongst those entry points only machine_check is one that will interrupt an
IRQS-off critical section asynchronously - and machine check events are rare.
The other main asynchronous entries are NMI entries, which can be very high-freq
with perf profiling, but they are special: they don't use the 'idtentry' macro but
are open coded and restore user CR3 unconditionally so don't have this bug.
Reported-and-tested-by: Josh Poimboeuf <[email protected]>
Reviewed-by: Andy Lutomirski <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Currently, x86_cache_size is of type int, which makes no sense as we
will never have a valid cache size equal or less than 0. So instead of
initializing this variable to -1, it can perfectly be initialized to 0
and use it as an unsigned variable instead.
Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Addresses-Coverity-ID: 1464429
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
For distributions with old userspace header files, the _sigfault
structure is different. mpx-mini-test fails with the following
error:
[root@Purley]# mpx-mini-test_64 tabletest
XSAVE is supported by HW & OS
XSAVE processor supported state mask: 0x2ff
XSAVE OS supported state mask: 0x2ff
BNDREGS: size: 64 user: 1 supervisor: 0 aligned: 0
BNDCSR: size: 64 user: 1 supervisor: 0 aligned: 0
starting mpx bounds table test
ERROR: siginfo bounds do not match shadow bounds for register 0
Fix it by using the correct offset of _lower/_upper in _sigfault.
RHEL needs this patch to work.
Signed-off-by: Rui Wang <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: e754aedc26 ("x86/mpx, selftests: Add MPX self test")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
For architectures providing their own implementation of
array_index_mask_nospec() in asm/barrier.h, attempting to use WARN_ONCE() to
complain about out-of-range parameters using WARN_ON() results in a mess
of mutually-dependent include files.
Rather than unpick the dependencies, simply have the core code in nospec.h
perform the checking for us.
Signed-off-by: Will Deacon <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Pull gfs2 fix from Bob Peterson:
"Fix regressions in the gfs2 iomap for block_map implementation we
recently discovered in commit 3974320ca6"
* tag 'gfs2-4.16.rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fixes to "Implement iomap for block_map"
Pull powerpc fixes from Michael Ellerman:
"A larger batch of fixes than we'd like. Roughly 1/3 fixes for new
code, 1/3 fixes for stable and 1/3 minor things.
There's four commits fixing bugs when using 16GB huge pages on hash,
caused by some of the preparatory changes for pkeys.
Two fixes for bugs in the enhanced IRQ soft masking for local_t, one
of which broke KVM in some circumstances.
Four fixes for Power9. The most bizarre being a bug where futexes
stopped working because a NULL pointer dereference didn't trap during
early boot (it aliased the kernel mapping). A fix for memory hotplug
when using the Radix MMU, and a fix for live migration of guests using
the Radix MMU.
Two fixes for hotplug on pseries machines. One where we weren't
correctly updating NUMA info when CPUs are added and removed. And the
other fixes crashes/hangs seen when doing memory hot remove during
boot, which is apparently a thing people do.
Finally a handful of build fixes for obscure configs and other minor
fixes.
Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin
Ian King, Daniel Henrique Barboza, Florian Weimer, Guenter Roeck,
Harish, Laurent Vivier, Madhavan Srinivasan, Mauricio Faria de
Oliveira, Nathan Fontenot, Nicholas Piggin, Sam Bobroff"
* tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Fix to use ucontext_t instead of struct ucontext
powerpc/kdump: Fix powernv build break when KEXEC_CORE=n
powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug
powerpc/mm/hash64: Zero PGD pages on allocation
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb
powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled
powerpc/mm: Fix crashes with 16G huge pages
powerpc/mm: Flush radix process translations when setting MMU type
powerpc/vas: Don't set uses_vas for kernel windows
powerpc/pseries: Enable RAS hotplug events later
powerpc/mm/radix: Split linear mapping on hot-unplug
powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID
ocxl: fix signed comparison with less than zero
powerpc/64s: Fix may_hard_irq_enable() for PMI soft masking
powerpc/64s: Fix MASKABLE_RELON_EXCEPTION_HV_OOL macro
powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
It turns out that commit 3974320ca6 "Implement iomap for block_map"
introduced a few bugs that trigger occasional failures with xfstest
generic/476:
In gfs2_iomap_begin, we jump to do_alloc when we determine that we are
beyond the end of the allocated metadata (height > ip->i_height).
There, we can end up calling hole_size with a metapath that doesn't
match the current metadata tree, which doesn't make sense. After
untangling the code at do_alloc, fix this by checking if the block we
are looking for is within the range of allocated metadata.
In addition, add a BUG() in case gfs2_iomap_begin is accidentally called
for reading stuffed files: this is handled separately. Make sure we
don't truncate iomap->length for reads beyond the end of the file; in
that case, the entire range counts as a hole.
Finally, revert to taking a bitmap write lock when doing allocations.
It's unclear why that change didn't lead to any failures during testing.
Signed-off-by: Andreas Gruenbacher <[email protected]>
Signed-off-by: Bob Peterson <[email protected]>
Pull MIPS fix from James Hogan:
"A single change (and associated DT binding update) to allow the
address of the MIPS Cluster Power Controller (CPC) to be chosen by DT,
which allows SMP to work on generic MIPS kernels where the bootloader
hasn't configured the CPC address (i.e. the new Ranchu platform)"
* tag 'mips_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
MIPS: CPC: Map registers using DT in mips_cpc_default_phys_base()
dt-bindings: Document mti,mips-cpc binding
In the following commit:
ce0fa3e56a ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages")
... we added code to memory_failure() to unmap the page from the
kernel 1:1 virtual address space to avoid speculative access to the
page logging additional errors.
But memory_failure() may not always succeed in taking the page offline,
especially if the page belongs to the kernel. This can happen if
there are too many corrected errors on a page and either mcelog(8)
or drivers/ras/cec.c asks to take a page offline.
Since we remove the 1:1 mapping early in memory_failure(), we can
end up with the page unmapped, but still in use. On the next access
the kernel crashes :-(
There are also various debug paths that call memory_failure() to simulate
occurrence of an error. Since there is no actual error in memory, we
don't need to map out the page for those cases.
Revert most of the previous attempt and keep the solution local to
arch/x86/kernel/cpu/mcheck/mce.c. Unmap the page only when:
1) there is a real error
2) memory_failure() succeeds.
All of this only applies to 64-bit systems. 32-bit kernel doesn't map
all of memory into kernel space. It isn't worth adding the code to unmap
the piece that is mapped because nobody would run a 32-bit kernel on a
machine that has recoverable machine checks.
Signed-off-by: Tony Luck <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Robert (Persistent Memory) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected] #v4.14
Fixes: ce0fa3e56a ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages")
Signed-off-by: Ingo Molnar <[email protected]>
Jessica Yu