Commit Graph

1025369 Commits

Author SHA1 Message Date
Adrian Hunter
9bde93a79a perf script: Add dlfilter__filter_event_early()
filter_event_early() can be more than 30% faster than filter_event()
because it is called before internal filtering. In other respects it
is the same as filter_event(), except that it will be passed events
that have yet to be filtered out.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210627131818.810-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Adrian Hunter
291961fc3c perf script: Add API for filtering via dynamically loaded shared object
In some cases, users want to filter very large amounts of data (e.g.
from AUX area tracing like Intel PT) looking for something specific.
While scripting such as Python can be used, Python is 10 to 20 times
slower than C. So define a C API so that custom filters can be written
and loaded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210627131818.810-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Arnaldo Carvalho de Melo
c435c166dc perf llvm: Return -ENOMEM when asprintf() fails
Zhihao sent a patch but it made llvm__compile_bpf() return what
asprintf() returns on error, which is just -1, but since this function
returns -errno, fix it by returning -ENOMEM for this case instead.

Fixes: cb76371441 ("perf llvm: Allow passing options to llc ...")
Fixes: 5eab5a7ee0 ("perf llvm: Display eBPF compiling command ...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210609115945.2193194-1-chengzhihao1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
James Clark
0323dea318 perf cs-etm: Delay decode of non-timeless data until cs_etm__flush_events()
Currently, timeless mode starts the decode on PERF_RECORD_EXIT, and
non-timeless mode starts decoding on the fist PERF_RECORD_AUX record.

This can cause the "data has no samples!" error if the first
PERF_RECORD_AUX record comes before the first (or any relevant)
PERF_RECORD_MMAP2 record because the mmaps are required by the decoder
to access the binary data.

This change pushes the start of non-timeless decoding to the very end of
parsing the file. The PERF_RECORD_EXIT event can't be used because it
might not exist in system-wide or snapshot modes.

I have not been able to find the exact cause for the events to be
intermittently in the wrong order in the basic scenario:

	perf record -e cs_etm/@tmc_etr0/u top

But it can be made to happen every time with the --delay option. This is
because "enable_on_exec" is disabled, which causes tracing to start
before the process to be launched is exec'd. For example:

	perf record -e cs_etm/@tmc_etr0/u --delay=1 top
	perf report -D | grep 'AUX\|MAP'

	0 16714475632740 0x520 [0x40]: PERF_RECORD_AUX offset: 0 size: 0x30 flags: 0 []
	0 16714476494960 0x5d0 [0x40]: PERF_RECORD_AUX offset: 0x30 size: 0x30 flags: 0 []
	0 16714478208900 0x660 [0x40]: PERF_RECORD_AUX offset: 0x60 size: 0x30 flags: 0 []
	4294967295 16714478293340 0x700 [0x70]: PERF_RECORD_MMAP2 8712/8712: [0x557a460000(0x54000) @ 0 00:17 5329258 0]: r-xp /usr/bin/top
	4294967295 16714478353020 0x770 [0x88]: PERF_RECORD_MMAP2 8712/8712: [0x7f86f72000(0x34000) @ 0 00:17 5214354 0]: r-xp /usr/lib/aarch64-linux-gnu/ld-2.31.so

Another scenario in which decoding from the first aux record fails is a
workload that forks. Although the aux record comes after 'bash', it
comes before 'top', which is what we are interested in. For example:

	perf record -e cs_etm/@tmc_etr0/u -- bash -c top
	perf report -D | grep 'AUX\|MAP'

	4294967295 16853946421300 0x510 [0x70]: PERF_RECORD_MMAP2 8723/8723: [0x558f280000(0x142000) @ 0 00:17 5213953 0]: r-xp /usr/bin/bash
	4294967295 16853946543560 0x580 [0x88]: PERF_RECORD_MMAP2 8723/8723: [0x7fbba6e000(0x34000) @ 0 00:17 5214354 0]: r-xp /usr/lib/aarch64-linux-gnu/ld-2.31.so
	4294967295 16853946628420 0x608 [0x68]: PERF_RECORD_MMAP2 8723/8723: [0x7fbba9e000(0x1000) @ 0 00:00 0 0]: r-xp [vdso]
	0 16853947067300 0x690 [0x40]: PERF_RECORD_AUX offset: 0 size: 0x3a60 flags: 0 []
	...
	0 16853966602580 0x1758 [0x40]: PERF_RECORD_AUX offset: 0xc2470 size: 0x30 flags: 0 []
	4294967295 16853967119860 0x1818 [0x70]: PERF_RECORD_MMAP2 8723/8723: [0x5559e70000(0x54000) @ 0 00:17 5329258 0]: r-xp /usr/bin/top
	4294967295 16853967181620 0x1888 [0x88]: PERF_RECORD_MMAP2 8723/8723: [0x7f9ed06000(0x34000) @ 0 00:17 5214354 0]: r-xp /usr/lib/aarch64-linux-gnu/ld-2.31.so
	4294967295 16853967237180 0x1910 [0x68]: PERF_RECORD_MMAP2 8723/8723: [0x7f9ed36000(0x1000) @ 0 00:00 0 0]: r-xp [vdso]

A third scenario is when the majority of time is spent in a shared
library that is not loaded at startup. For example a dynamically loaded
plugin.

Testing
=======

Testing was done by checking if any samples that are present in the
old output are missing from the new output. Timestamps must be
stripped out with awk because now they are set to the last AUX sample,
rather than the first:

	./perf script $4 | awk '!($4="")' > new.script
	./perf-default script $4 | awk '!($4="")' > default.script
	comm -13 <(sort -u new.script) <(sort -u default.script)

Testing showed that the new output is a superset of the old. When lines
appear in the comm output, it is not because they are missing but
because [unknown] is now resolved to sensible locations. For example
last putp branch here now resolves to libtinfo, so it's not missing
from the output, but is actually improved:

Old:
	top 305 [001]  1 branches:uH: 402830 _init+0x30 (/usr/bin/top.procps) => 404a1c [unknown] (/usr/bin/top.procps)
	top 305 [001]  1 branches:uH: 404a20 [unknown] (/usr/bin/top.procps) => 402970 putp@plt+0x0 (/usr/bin/top.procps)
	top 305 [001]  1 branches:uH: 40297c putp@plt+0xc (/usr/bin/top.procps) => 0 [unknown] ([unknown])
New:
	top 305 [001]  1 branches:uH: 402830 _init+0x30 (/usr/bin/top.procps) => 404a1c [unknown] (/usr/bin/top.procps)
	top 305 [001]  1 branches:uH: 404a20 [unknown] (/usr/bin/top.procps) => 402970 putp@plt+0x0 (/usr/bin/top.procps)
	top 305 [001]  1 branches:uH: 40297c putp@plt+0xc (/usr/bin/top.procps) => 7f8ab39208 putp+0x0 (/lib/libtinfo.so.5.9)

In the following two modes, decoding now works and the "data has no
samples!" error is not displayed any more:

	perf record -e cs_etm/@tmc_etr0/u -- bash -c top
	perf record -e cs_etm/@tmc_etr0/u --delay=1 top

In snapshot mode, there is also an improvement to decoding. Previously
samples for the 'kill' process that was used to send SIGUSR2 were
completely missing, because the process hadn't started yet. But now
there are additional samples present:

	perf record -e cs_etm/@tmc_etr0/u --snapshot -a
	perf script

		stress 19380 [003] 161627.938153:    1000000    instructions:uH:      aaaabb612fb4 [unknown] (/usr/bin/stress)
		  kill 19644 [000] 161627.938153:    1000000    instructions:uH:      ffffae0ef210 [unknown] (/lib/aarch64-linux-gnu/ld-2.27.so)
		stress 19380 [003] 161627.938153:    1000000    instructions:uH:      ffff9e754d40 random_r+0x20 (/lib/aarch64-linux-gnu/libc-2.27.so)

Also tested was the round trip of 'perf inject' followed by 'perf
report' which has the same differences and improvements.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Branislav Rankov <branislav.rankov@arm.com>
Cc: Denis Nikitin <denik@chromium.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20210609130421.13934-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Arnaldo Carvalho de Melo
f88bb1cb3e tools headers UAPI: Synch KVM's svm.h header with the kernel
To pick up the changes from:

  59d21d67f3 ("KVM: SVM: Software reserved fields")

Picking the new SVM_EXIT_SW exit reasons.

Addressing this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/svm.h' differs from latest version at 'arch/x86/include/uapi/asm/svm.h'
  diff -u tools/arch/x86/include/uapi/asm/svm.h arch/x86/include/uapi/asm/svm.h

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vineeth Pillai <viremana@linux.microsoft.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Arnaldo Carvalho de Melo
795c4ab87e tools kvm headers arm64: Update KVM headers from the kernel sources
To pick the changes from:

  f0376edb1d ("KVM: arm64: Add ioctl to fetch/store tags in a guest")

That don't causes any changes in tooling (when built on x86), only
addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm64/include/uapi/asm/kvm.h'
  diff -u tools/arch/arm64/include/uapi/asm/kvm.h arch/arm64/include/uapi/asm/kvm.h

Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Arnaldo Carvalho de Melo
e48f62aece tools headers UAPI: Sync linux/kvm.h with the kernel sources
To pick the changes in:

  19238e75bd ("kvm: x86: Allow userspace to handle emulation errors")
  cb082bfab5 ("KVM: stats: Add fd-based API to read binary stats data")
  b87cc116c7 ("KVM: PPC: Book3S HV: Add KVM_CAP_PPC_RPT_INVALIDATE capability")
  f0376edb1d ("KVM: arm64: Add ioctl to fetch/store tags in a guest")
  0dbb112304 ("KVM: X86: Introduce KVM_HC_MAP_GPA_RANGE hypercall")
  6dba940352 ("KVM: x86: Introduce KVM_GET_SREGS2 / KVM_SET_SREGS2")
  644f706719 ("KVM: x86: hyper-v: Introduce KVM_CAP_HYPERV_ENFORCE_CPUID")

That automatically adds support for these new ioctls:

  $ tools/perf/trace/beauty/kvm_ioctl.sh > before
  $ cp include/uapi/linux/kvm.h tools/include/uapi/linux/kvm.h
  $ tools/perf/trace/beauty/kvm_ioctl.sh > after
  $ diff -u before after
  --- before	2021-07-01 13:42:07.006387354 -0300
  +++ after	2021-07-01 13:45:16.051649301 -0300
  @@ -95,6 +95,9 @@
   	[0xc9] = "XEN_HVM_SET_ATTR",
   	[0xca] = "XEN_VCPU_GET_ATTR",
   	[0xcb] = "XEN_VCPU_SET_ATTR",
  +	[0xcc] = "GET_SREGS2",
  +	[0xcd] = "SET_SREGS2",
  +	[0xce] = "GET_STATS_FD",
   	[0xe0] = "CREATE_DEVICE",
   	[0xe1] = "SET_DEVICE_ATTR",
   	[0xe2] = "GET_DEVICE_ATTR",
  $

This silences these perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/kvm.h' differs from latest version at 'arch/x86/include/uapi/asm/kvm.h'
  diff -u tools/arch/x86/include/uapi/asm/kvm.h arch/x86/include/uapi/asm/kvm.h
  Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
  diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h

Cc: Aaron Lewis <aaronlewis@google.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Jing Zhang <jingzhangos@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Arnaldo Carvalho de Melo
cc200a7de9 tools headers cpufeatures: Sync with the kernel sources
To pick the changes from:

  1348924ba8 ("x86/msr: Define new bits in TSX_FORCE_ABORT MSR")
  cbcddaa33d ("perf/x86/rapl: Use CPUID bit on AMD and Hygon parts")

This only causes these perf files to be rebuilt:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h

Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:37 -03:00
Arnaldo Carvalho de Melo
14c6ef2b55 tools include UAPI: Update linux/mount.h copy
To pick the changes from:

  dd8b477f9a ("mount: Support "nosymfollow" in new mount api")

That ends up adding support for the new MOUNT_ATTR_NOSYMFOLLOW mount
attribute:

  $ tools/perf/trace/beauty/fsmount.sh > before
  $ cp include/uapi/linux/mount.h tools/include/uapi/linux/mount.h
  $ tools/perf/trace/beauty/fsmount.sh > after
  $ diff -u before after
  --- before	2021-07-01 13:34:04.542517355 -0300
  +++ after	2021-07-01 13:34:12.423694537 -0300
  @@ -7,4 +7,5 @@
   	[ilog2(0x00000020) + 1] = "STRICTATIME",
   	[ilog2(0x00000080) + 1] = "NODIRATIME",
   	[ilog2(0x00100000) + 1] = "IDMAP",
  +	[ilog2(0x00200000) + 1] = "NOSYMFOLLOW",
   };
  $

So now one can use it in --filter expressions for tracepoints.

This silences this perf build warnings:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/mount.h' differs from latest version at 'include/uapi/linux/mount.h'
  diff -u tools/include/uapi/linux/mount.h include/uapi/linux/mount.h

Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Arnaldo Carvalho de Melo
04df0dc118 tools arch x86: Sync the msr-index.h copy with the kernel sources
To pick up the changes from these csets:

  1348924ba8 ("x86/msr: Define new bits in TSX_FORCE_ABORT MSR")

That cause no changes to tooling:

  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
  $ diff -u before after
  $

Just silences this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

Cc: Borislav Petkov <bp@suse.de>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Leo Yan
8941ba502f perf arm-spe: Don't wait for PERF_RECORD_EXIT event
When decode Arm SPE trace, it waits for PERF_RECORD_EXIT event (the last
perf event) for processing trace data, which is needless and even might
cause logic error, e.g. it might fail to correlate perf events with Arm
SPE events correctly.

So this patch removes the condition checking for PERF_RECORD_EXIT event.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210519071939.1598923-6-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Leo Yan
afb5e9e47f perf arm-spe: Bail out if the trace is later than perf event
It's possible that record in Arm SPE trace is later than perf event and
vice versa.  This asks to correlate the perf events and Arm SPE
synthesized events to be processed in the manner of correct timing.

To achieve the time ordering, this patch reverses the flow, it firstly
calls arm_spe_sample() and then calls arm_spe_decode().  By comparing
the timestamp value and detect the perf event is coming earlier than Arm
SPE trace data, it bails out from the decoding loop, the last record is
pushed into auxtrace stack and is deferred to generate sample.  To track
the timestamp, everytime it updates timestamp for the latest record.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20210519071939.1598923-5-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Leo Yan
85498f756f perf arm-spe: Assign kernel time to synthesized event
In current code, it assigns the arch timer counter to the synthesized
samples Arm SPE trace, thus the samples don't contain the kernel time
but only contain the raw counter value.

To fix the issue, this patch converts the timer counter to kernel time
and assigns it to sample timestamp.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20210519071939.1598923-4-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Leo Yan
630519014c perf arm-spe: Convert event kernel time to counter value
When handle a perf event, Arm SPE decoder needs to decide if this perf
event is earlier or later than the samples from Arm SPE trace data; to
do comparision, it needs to use the same unit for the time.

This patch converts the event kernel time to arch timer's counter value,
thus it can be used to compare with counter value contained in Arm SPE
Timestamp packet.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20210519071939.1598923-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Leo Yan
c210c30696 perf arm-spe: Save clock parameters from TIME_CONV event
During the recording phase, "perf record" tool synthesizes event
PERF_RECORD_TIME_CONV for the hardware clock parameters and saves the
event into the data file.

Afterwards, when processing the data file, the event TIME_CONV will be
processed at the very early time and is stored into session context.

This patch extracts these parameters from the session context and saves
into the structure "spe->tc" with the type perf_tsc_conversion, so that
the parameters are ready for conversion between clock counter and time
stamp.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20210519071939.1598923-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Leo Yan
2f01c200d4 perf cs-etm: Remove callback cs_etm_find_snapshot()
The callback cs_etm_find_snapshot() is invoked for snapshot mode, its
main purpose is to find the correct AUX trace data and returns "head"
and "old" (we can call "old" as "old head") to the caller, the caller
__auxtrace_mmap__read() uses these two pointers to decide the AUX trace
data size.

This patch removes cs_etm_find_snapshot() with below reasons:

- The first thing in cs_etm_find_snapshot() is to check if the head has
  wrapped around, if it is not, directly bails out.  The checking is
  pointless, this is because the "head" and "old" pointers both are
  monotonical increasing so they never wrap around.

- cs_etm_find_snapshot() adjusts the "head" and "old" pointers and
  assumes the AUX ring buffer is fully filled with the hardware trace
  data, so it always subtracts the difference "mm->len" from "head" to
  get "old".  Let's imagine the snapshot is taken in very short
  interval, the tracers only fill a small chunk of the trace data into
  the AUX ring buffer, in this case, it's wrongly to copy the whole the
  AUX ring buffer to perf file.

- As the "head" and "old" pointers are monotonically increased, the
  function __auxtrace_mmap__read() handles these two pointers properly.
  It calculates the reminders for these two pointers, and the size is
  clamped to be never more than "snapshot_size".  We can simply reply on
  the function __auxtrace_mmap__read() to calculate the correct result
  for data copying, it's not necessary to add Arm CoreSight specific
  callback.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Daniel Kiss <daniel.kiss@arm.com>
Cc: Denis Nikitin <denik@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: http://lore.kernel.org/lkml/20210701093537.90759-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:36 -03:00
Namhyung Kim
d6a735ef32 perf bpf_counter: Move common functions to bpf_counter.h
Some helper functions will be used for cgroup counting too.  Move them
to a header file for sharing.

Committer notes:

Fix the build on older systems with:

  -       struct bpf_map_info map_info = {0};
  +       struct bpf_map_info map_info = { .id = 0, };

This wasn't breaking the build in such systems as bpf_counter.c isn't
built due to:

tools/perf/util/Build:

  perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o

The bpf_counter.h file on the other hand is included from places that
are built everywhere.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210625071826.608504-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-01 16:14:19 -03:00
Linus Torvalds
911a2997a5 \n
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Merge tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull misc fs updates from Jan Kara:
 "The new quotactl_fd() syscall (remake of quotactl_path() syscall that
  got introduced & disabled in 5.13 cycle), and couple of udf, reiserfs,
  isofs, and writeback fixes and cleanups"

* tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  writeback: fix obtain a reference to a freeing memcg css
  quota: remove unnecessary oom message
  isofs: remove redundant continue statement
  quota: Wire up quotactl_fd syscall
  quota: Change quotactl_path() systcall to an fd-based one
  reiserfs: Remove unneed check in reiserfs_write_full_page()
  udf: Fix NULL pointer dereference in udf_symlink function
  reiserfs: add check for invalid 1st journal block
2021-07-01 12:06:39 -07:00
Paul Burton
4030a6e6a6 tracing: Resize tgid_map to pid_max, not PID_MAX_DEFAULT
Currently tgid_map is sized at PID_MAX_DEFAULT entries, which means that
on systems where pid_max is configured higher than PID_MAX_DEFAULT the
ftrace record-tgid option doesn't work so well. Any tasks with PIDs
higher than PID_MAX_DEFAULT are simply not recorded in tgid_map, and
don't show up in the saved_tgids file.

In particular since systemd v243 & above configure pid_max to its
highest possible 1<<22 value by default on 64 bit systems this renders
the record-tgids option of little use.

Increase the size of tgid_map to the configured pid_max instead,
allowing it to cover the full range of PIDs up to the maximum value of
PID_MAX_LIMIT if the system is configured that way.

On 64 bit systems with pid_max == PID_MAX_LIMIT this will increase the
size of tgid_map from 256KiB to 16MiB. Whilst this 64x increase in
memory overhead sounds significant 64 bit systems are presumably best
placed to accommodate it, and since tgid_map is only allocated when the
record-tgid option is actually used presumably the user would rather it
spends sufficient memory to actually record the tgids they expect.

The size of tgid_map could also increase for CONFIG_BASE_SMALL=y
configurations, but these seem unlikely to be systems upon which people
are both configuring a large pid_max and running ftrace with record-tgid
anyway.

Of note is that we only allocate tgid_map once, the first time that the
record-tgid option is enabled. Therefore its size is only set once, to
the value of pid_max at the time the record-tgid option is first
enabled. If a user increases pid_max after that point, the saved_tgids
file will not contain entries for any tasks with pids beyond the earlier
value of pid_max.

Link: https://lkml.kernel.org/r/20210701172407.889626-2-paulburton@google.com

Fixes: d914ba37d7 ("tracing: Add support for recording tgid of tasks")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Paul Burton <paulburton@google.com>
[ Fixed comment coding style ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-07-01 14:18:53 -04:00
Manfred Spraul
b869d5be0a ipc/util.c: use binary search for max_idx
If semctl(), msgctl() and shmctl() are called with IPC_INFO, SEM_INFO,
MSG_INFO or SHM_INFO, then the return value is the index of the highest
used index in the kernel's internal array recording information about all
SysV objects of the requested type for the current namespace.  (This
information can be used with repeated ..._STAT or ..._STAT_ANY operations
to obtain information about all SysV objects on the system.)

There is a cache for this value.  But when the cache needs up be updated,
then the highest used index is determined by looping over all possible
values.  With the introduction of IPCMNI_EXTEND_SHIFT, this could be a
loop over 16 million entries.  And due to /proc/sys/kernel/*next_id, the
index values do not need to be consecutive.

With <write 16000000 to msg_next_id>, msgget(), msgctl(,IPC_RMID) in a
loop, I have observed a performance increase of around factor 13000.

As there is no get_last() function for idr structures: Implement a
"get_last()" using a binary search.

As far as I see, ipc is the only user that needs get_last(), thus
implement it in ipc/util.c and not in a central location.

[akpm@linux-foundation.org: tweak comment, fix typo]

Link: https://lkml.kernel.org/r/20210425075208.11777-2-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:07 -07:00
Manfred Spraul
17d056e0bd ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
The patch solves three weaknesses in ipc/sem.c:

1) The initial read of use_global_lock in sem_lock() is an intentional
   race.  KCSAN detects these accesses and prints a warning.

2) The code assumes that plain C read/writes are not mangled by the CPU
   or the compiler.

3) The comment it sysvipc_sem_proc_show() was hard to understand: The
   rest of the comments in ipc/sem.c speaks about sem_perm.lock, and
   suddenly this function speaks about ipc_lock_object().

To solve 1) and 2), use READ_ONCE()/WRITE_ONCE().  Plain C reads are used
in code that owns sma->sem_perm.lock.

The comment is updated to solve 3)

[manfred@colorfullife.com: use READ_ONCE()/WRITE_ONCE() for use_global_lock]
  Link: https://lkml.kernel.org/r/20210627161919.3196-3-manfred@colorfullife.com

Link: https://lkml.kernel.org/r/20210514175319.12195-1-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:07 -07:00
Vasily Averin
bc8136a543 ipc: use kmalloc for msg_queue and shmid_kernel
msg_queue and shmid_kernel are quite small objects, no need to use
kvmalloc for them.  mhocko@: "Both of them are 256B on most 64b systems."

Previously these objects was allocated via ipc_alloc/ipc_rcu_alloc(),
common function for several ipc objects.  It had kvmalloc call inside().
Later, this function went away and was finally replaced by direct kvmalloc
call, and now we can use more suitable kmalloc/kfree for them.

Link: https://lkml.kernel.org/r/0d0b6c9b-8af3-29d8-34e2-a565c53780f3@virtuozzo.com
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:07 -07:00
Vasily Averin
fc37a3b8b4 ipc sem: use kvmalloc for sem_undo allocation
Patch series "ipc: allocations cleanup", v2.

Some ipc objects use the wrong allocation functions: small objects can use
kmalloc(), and vice versa, potentially large objects can use kmalloc().

This patch (of 2):

Size of sem_undo can exceed one page and with the maximum possible nsems =
32000 it can grow up to 64Kb.  Let's switch its allocation to kvmalloc to
avoid user-triggered disruptive actions like OOM killer in case of
high-order memory shortage.

User triggerable high order allocations are quite a problem on heavily
fragmented systems.  They can be a DoS vector.

Link: https://lkml.kernel.org/r/ebc3ac79-3190-520d-81ce-22ad194986ec@virtuozzo.com
Link: https://lkml.kernel.org/r/a6354fd9-2d55-2e63-dd4d-fa7dc1d11134@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:07 -07:00
Yu Kuai
3b52348345 lib/decompressors: remove set but not used variabled 'level'
Fixes gcc '-Wunused-but-set-variable' warning:

lib/decompress_unlzo.c:46:5: warning: variable `level' set but
not used [-Wunused-but-set-variable]

It is never used and so can be removed.

[akpm@linux-foundation.org: warning: value computed is not used]

Link: https://lkml.kernel.org/r/20210514062050.3532344-1-yukuai3@huawei.com
Fixes: 7dd65feb6c ("lib: add support for LZO-compressed kernels")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Dave Hansen
d892454b68 selftests/vm/pkeys: exercise x86 XSAVE init state
On x86, there is a set of instructions used to save and restore register
state collectively known as the XSAVE architecture.  There are about a
dozen different features managed with XSAVE.  The protection keys
register, PKRU, is one of those features.

The hardware optimizes XSAVE by tracking when the state has not changed
from its initial (init) state.  In this case, it can avoid the cost of
writing state to memory (it would usually just be a bunch of 0's).

When the pkey register is 0x0 the hardware optionally choose to track the
register as being in the init state (optimize away the writes).  AMD CPUs
do this more aggressively compared to Intel.

On x86, PKRU is rarely in its (very permissive) init state.  Instead, the
value defaults to something very restrictive.  It is not surprising that
bugs have popped up in the rare cases when PKRU reaches its init state.

Add a protection key selftest which gets the protection keys register into
its init state in a way that should work on Intel and AMD.  Then, do a
bunch of pkey register reads to watch for inadvertent changes.

This adds "-mxsave" to CFLAGS for all the x86 vm selftests in order to
allow use of the XSAVE instruction __builtin functions.  This will make
the builtins available on all of the vm selftests, but is expected to be
harmless.

Link: https://lkml.kernel.org/r/20210611164202.1849B712@viggo.jf.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Dave Hansen
6039ca2549 selftests/vm/pkeys: refill shadow register after implicit kernel write
The pkey test code keeps a "shadow" of the pkey register around.  This
ensures that any bugs which might write to the register can be caught more
quickly.

Generally, userspace has a good idea when the kernel is going to write to
the register.  For instance, alloc_pkey() is passed a permission mask.
The caller of alloc_pkey() can update the shadow based on the return value
and the mask.

But, the kernel can also modify the pkey register in a more sneaky way.
For mprotect(PROT_EXEC) mappings, the kernel will allocate a pkey and
write the pkey register to create an execute-only mapping.  The kernel
never tells userspace what key it uses for this.

This can cause the test to fail with messages like:

	protection_keys_64.2: pkey-helpers.h:132: _read_pkey_reg: Assertion `pkey_reg == shadow_pkey_reg' failed.

because the shadow was not updated with the new kernel-set value.

Forcibly update the shadow value immediately after an mprotect().

Link: https://lkml.kernel.org/r/20210611164200.EF76AB73@viggo.jf.intel.com
Fixes: 6af17cf89e ("x86/pkeys/selftests: Add PROT_EXEC test")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Dave Hansen
bf68294a2e selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
The alloc_pkey() sefltest function wraps the sys_pkey_alloc() system call.
On success, it updates its "shadow" register value because
sys_pkey_alloc() updates the real register.

But, the success check is wrong.  pkey_alloc() considers any non-zero
return code to indicate success where the pkey register will be modified.
This fails to take negative return codes into account.

Consider only a positive return value as a successful call.

Link: https://lkml.kernel.org/r/20210611164157.87AB4246@viggo.jf.intel.com
Fixes: 5f23f6d082 ("x86/pkeys: Add self-tests")
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Dave Hansen
f36ef40762 selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
Patch series "selftests/vm/pkeys: Bug fixes and a new test".

There has been a lot of activity on the x86 front around the XSAVE
architecture which is used to context-switch processor state (among other
things).  In addition, AMD has recently joined the protection keys club by
adding processor support for PKU.

The AMD implementation helped uncover a kernel bug around the PKRU "init
state", which actually applied to Intel's implementation but was just
harder to hit.  This series adds a test which is expected to help find
this class of bug both on AMD and Intel.  All the work around pkeys on x86
also uncovered a few bugs in the selftest.

This patch (of 4):

The "random" pkey allocation code currently does the good old:

	srand((unsigned int)time(NULL));

*But*, it unfortunately does this on every random pkey allocation.

There may be thousands of these a second.  time() has a one second
resolution.  So, each time alloc_random_pkey() is called, the PRNG is
*RESET* to time().  This is nasty.  Normally, if you do:

	srand(<ANYTHING>);
	foo = rand();
	bar = rand();

You'll be quite guaranteed that 'foo' and 'bar' are different.  But, if
you do:

	srand(1);
	foo = rand();
	srand(1);
	bar = rand();

You are quite guaranteed that 'foo' and 'bar' are the *SAME*.  The recent
"fix" effectively forced the test case to use the same "random" pkey for
the whole test, unless the test run crossed a second boundary.

Only run srand() once at program startup.

This explains some very odd and persistent test failures I've been seeing.

Link: https://lkml.kernel.org/r/20210611164153.91B76FB8@viggo.jf.intel.com
Link: https://lkml.kernel.org/r/20210611164155.192D00FF@viggo.jf.intel.com
Fixes: 6e373263ce ("selftests/vm/pkeys: fix alloc_random_pkey() to make it really random")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Marco Elver
540540d06e kcov: add __no_sanitize_coverage to fix noinstr for all architectures
Until now no compiler supported an attribute to disable coverage
instrumentation as used by KCOV.

To work around this limitation on x86, noinstr functions have their
coverage instrumentation turned into nops by objtool.  However, this
solution doesn't scale automatically to other architectures, such as
arm64, which are migrating to use the generic entry code.

Clang [1] and GCC [2] have added support for the attribute recently.
[1] 280333021e
[2] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=cec4d4a6782c9bd8d071839c50a239c49caca689
The changes will appear in Clang 13 and GCC 12.

Add __no_sanitize_coverage for both compilers, and add it to noinstr.

Note: In the Clang case, __has_feature(coverage_sanitizer) is only true if
the feature is enabled, and therefore we do not require an additional
defined(CONFIG_KCOV) (like in the GCC case where __has_attribute(..) is
always true) to avoid adding redundant attributes to functions if KCOV is
off.  That being said, compilers that support the attribute will not
generate errors/warnings if the attribute is redundantly used; however,
where possible let's avoid it as it reduces preprocessed code size and
associated compile-time overheads.

[elver@google.com: Implement __has_feature(coverage_sanitizer) in Clang]
  Link: https://lkml.kernel.org/r/20210527162655.3246381-1-elver@google.com
[elver@google.com: add comment explaining __has_feature() in Clang]
  Link: https://lkml.kernel.org/r/20210527194448.3470080-1-elver@google.com

Link: https://lkml.kernel.org/r/20210525175819.699786-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Alexey Dobriyan
bae7702a17 exec: remove checks in __register_bimfmt()
Delete NULL check, all callers pass valid pointer.

Delete ->load_binary check -- failure to provide hook in a custom module
will be very noticeable at the very first execve call.

Link: https://lkml.kernel.org/r/YK1Gy1qXaLAR+tPl@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Al Viro
97c885d585 x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
Currently we handle SS_AUTODISARM as soon as we have stored the altstack
settings into sigframe - that's the point when we have set the things up
for eventual sigreturn to restore the old settings.  And if we manage to
set the sigframe up (we are not done with that yet), everything's fine.
However, in case of failure we end up with sigframe-to-be abandoned and
SIGSEGV force-delivered.  And in that case we end up with inconsistent
rules - late failures have altstack reset, early ones do not.

It's trivial to get consistent behaviour - just handle SS_AUTODISARM once
we have set the sigframe up and are committed to entering the handler,
i.e.  in signal_delivered().

Link: https://lore.kernel.org/lkml/20200404170604.GN23230@ZenIV.linux.org.uk/
Link: https://github.com/ClangBuiltLinux/linux/issues/876
Link: https://lkml.kernel.org/r/20210422230846.1756380-1-ndesaulniers@google.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Chung-Chiang Cheng
c3eb84092b hfsplus: report create_date to kstat.btime
The create_date field of inode in hfsplus is corresponding to
kstat.btime and could be reported in statx.

Link: https://lkml.kernel.org/r/20210416172147.8736-1-cccheng@synology.com
Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: James Morris <jamorris@linux.microsoft.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Zhen Lei
7dcae11f4c hfsplus: remove unnecessary oom message
Fixes scripts/checkpatch.pl warning:
WARNING: Possible unnecessary 'out of memory' message

Remove it can help us save a bit of memory.

Link: https://lkml.kernel.org/r/20210617084944.1279-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Colin Ian King
f4048e5aa1 nilfs2: remove redundant continue statement in a while-loop
The continue statement at the end of the while-loop is redundant,
remove it.

Addresses-Coverity: ("Continue has no effect")
Link: https://lkml.kernel.org/r/20210621100519.10257-1-colin.king@canonical.com
Link: https://lkml.kernel.org/r/1624557664-17159-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Barry Song
66ce75144d kprobes: remove duplicated strong free_insn_page in x86 and s390
free_insn_page() in x86 and s390 is same with the common weak function in
kernel/kprobes.c.  Plus, the comment "Recover page to RW mode before
releasing it" in x86 seems insensible to be there since resetting mapping
is done by common code in vfree() of module_memfree().  So drop these two
duplicated strong functions and related comment, then mark the common one
in kernel/kprobes.c strong.

Link: https://lkml.kernel.org/r/20210608065736.32656-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Andrew Halaney
86d1919a4f init: print out unknown kernel parameters
It is easy to foobar setting a kernel parameter on the command line
without realizing it, there's not much output that you can use to assess
what the kernel did with that parameter by default.

Make it a little more explicit which parameters on the command line
_looked_ like a valid parameter for the kernel, but did not match anything
and ultimately got tossed to init.  This is very similar to the unknown
parameter message received when loading a module.

This assumes the parameters are processed in a normal fashion, some
parameters (dyndbg= for example) don't register their parameter with the
rest of the kernel's parameters, and therefore always show up in this list
(and are also given to init - like the rest of this list).

Another example is BOOT_IMAGE= is highlighted as an offender, which it
technically is, but is passed by LILO and GRUB so most systems will see
that complaint.

An example output where "foobared" and "unrecognized" are intentionally
invalid parameters:

  Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.12-dirty debug log_buf_len=4M foobared unrecognized=foo
  Unknown command line parameters: foobared BOOT_IMAGE=/boot/vmlinuz-5.12-dirty unrecognized=foo

Link: https://lkml.kernel.org/r/20210511211009.42259-1-ahalaney@redhat.com
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Borislav Petkov <bp@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Guenter Roeck
46b85bf967 checkpatch: do not complain about positive return values starting with EPOLL
checkpatch complains about positive return values of poll functions.
Example:

WARNING: return of an errno should typically be negative (ie: return -EPOLLIN)
+		return EPOLLIN;

Poll functions return positive values.  The defines for the return values
of poll functions all start with EPOLL, resulting in a number of false
positives.  An often used workaround is to assign poll function return
values to variables and returning that variable, but that is a less than
perfect solution.

There is no error definition which starts with EPOLL, so it is safe to
omit the warning for return values starting with EPOLL.

Link: https://lkml.kernel.org/r/20210622004334.638680-1-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Joe Perches <joe@perches.com>
Cc: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Joe Perches
690786511b checkpatch: improve the indented label test
checkpatch identifies a label only when a terminating colon
immediately follows an identifier.

Bitfield definitions can appear to be labels so ignore any
spaces between the identifier terminating colon and any digit
that may be used to define a bitfield length.

Miscellanea:

o Improve the initial checkpatch comment
o Use the more typical '&&' instead of 'and'
o Require the initial label character to be a non-digit
  (Can't use $Ident here because $Ident allows ## concatenation)
o Use $sline instead of $line to ignore comments
o Use '$sline !~ /.../' instead of '!($line =~ /.../)'

Link: https://lkml.kernel.org/r/b54d673e7cde7de5de0c9ba4dd57dd0858580ca4.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Manikishan Ghantasala <manikishanghantasala@gmail.com>
Cc: Alex Elder <elder@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Guenter Roeck
f9363b31d7 checkpatch: scripts/spdxcheck.py now requires python3
Since commit d0259c42ab ("spdxcheck.py: Use Python 3"), spdxcheck.py
explicitly expects to run as python3 script.  If "python" still points to
python v2.7 and the script is executed with "python scripts/spdxcheck.py",
the following error may be seen even if git-python is installed for
python3.

Traceback (most recent call last):
  File "scripts/spdxcheck.py", line 10, in <module>
    import git
ImportError: No module named git

To fix the problem, check for the existence of python3, check if
the script is executable and not just for its existence, and execute
it directly.

Link: https://lkml.kernel.org/r/20210505211720.447111-1-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Joe Perches <joe@perches.com>
Cc: Bert Vermeulen <bert@biot.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Dimitri John Ledkov
2c484419ef lib/decompress_unlz4.c: correctly handle zero-padding around initrds.
lz4 compatible decompressor is simple.  The format is underspecified and
relies on EOF notification to determine when to stop.  Initramfs buffer
format[1] explicitly states that it can have arbitrary number of zero
padding.  Thus when operating without a fill function, be extra careful to
ensure that sizes less than 4, or apperantly empty chunksizes are treated
as EOF.

To test this I have created two cpio initrds, first a normal one,
main.cpio.  And second one with just a single /test-file with content
"second" second.cpio.  Then i compressed both of them with gzip, and with
lz4 -l.  Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1
count=4).  To create four testcase initrds:

 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip
 2) main.cpio.lz4  + extra.cpio.lz4 = pad0.lz4
 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip
 4) main.cpio.lz4  + pad4 + extra.cpio.lz4 = pad4.lz4

The pad4 test-cases replicate the initrd load by grub, as it pads and
aligns every initrd it loads.

All of the above boot, however /test-file was not accessible in the initrd
for the testcase #4, as decoding in lz4 decompressor failed.  Also an
error message printed which usually is harmless.

Whith a patched kernel, all of the above testcases now pass, and
/test-file is accessible.

This fixes lz4 initrd decompress warning on every boot with grub.  And
more importantly this fixes inability to load multiple lz4 compressed
initrds with grub.  This patch has been shipping in Ubuntu kernels since
January 2021.

[1] ./Documentation/driver-api/early-userspace/buffer-format.rst

BugLink: https://bugs.launchpad.net/bugs/1835660
Link: https://lore.kernel.org/lkml/20210114200256.196589-1-xnox@ubuntu.com/ # v0
Link: https://lkml.kernel.org/r/20210513104831.432975-1-dimitri.ledkov@canonical.com
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Bongkyu Kim <bongkyu.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Rajat Asthana <thisisrast7@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Rajat Asthana
7fde9d6e83 lz4_decompress: declare LZ4_decompress_safe_withPrefix64k static
Declare LZ4_decompress_safe_withPrefix64k as static to fix sparse
warning:

> warning: symbol 'LZ4_decompress_safe_withPrefix64k' was not declared.
> Should it be static?

Link: https://lkml.kernel.org/r/20210511154345.610569-1-thisisrast7@gmail.com
Signed-off-by: Rajat Asthana <thisisrast7@gmail.com>
Reviewed-by: Nick Terrell <terrelln@fb.com>
Cc: Gao Xiang <hsiangkao@redhat.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Andy Shevchenko
4c52729377 kernel.h: split out kstrtox() and simple_strtox() to a separate header
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out kstrtox() and
simple_strtox() helpers.

At the same time convert users in header and lib folders to use new
header.  Though for time being include new header back to kernel.h to
avoid twisted indirected includes for existing users.

[andy.shevchenko@gmail.com: fix documentation references]
  Link: https://lkml.kernel.org/r/20210615220003.377901-1-andy.shevchenko@gmail.com

Link: https://lkml.kernel.org/r/20210611185815.44103-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Francis Laniel <laniel_francis@privacyrequired.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Kars Mulder <kerneldev@karsmulder.nl>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Matteo Croce
ce71efd039 lib/test_string.c: allow module removal
The test_string module can't be removed because it lacks an exit hook.
Since there is no reason for it to be permanent, add an empty one to allow
module removal.

Link: https://lkml.kernel.org/r/20210616234503.28678-1-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Alexey Dobriyan
ad65dcef3a lib: uninline simple_strtoull()
Gcc inlines simple_strtoull() too agressively.

Given that all 4 signatures match, everything very efficiently calls or
tailcalls into simple_strtoull():

	ffffffff81da0240 <simple_strtoll>:
	ffffffff81da0240:       80 3f 2d                cmp    BYTE PTR [rdi],0x2d
	ffffffff81da0243:       74 05                   je     ffffffff81da024a <simple_strtoll+0xa>
	ffffffff81da0245:       e9 76 ff ff ff          jmp    simple_strtoull
	ffffffff81da024a:       48 83 c7 01             add    rdi,0x1
	ffffffff81da024e:       e8 6d ff ff ff          call   simple_strtoull
	ffffffff81da0253:       48 f7 d8                neg    rax
	ffffffff81da0256:       c3                      ret

Space savings (on F34-ish .config)

	add/remove: 0/0 grow/shrink: 1/3 up/down: 52/-313 (-261)
	Function                                     old     new   delta
	vsscanf                                     2167    2219     +52
	simple_strtoul                                72       2     -70
	simple_strtoll                               143      23    -120
	simple_strtol                                143      20    -123

Link: https://lkml.kernel.org/r/YMO2zoOQk2eF34tn@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Alexey Dobriyan
1a58be6277 lib: memscan() fixlet
Generic version doesn't trucate second argument to char.

Older brother memchr() does as do s390, sparc and i386 assembly versions.

Fortunately, no code passes c >= 256.

Link: https://lkml.kernel.org/r/YLv4cCf0t5UPdyK+@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Zhen Lei
478485f6c0 lib/mpi: fix spelling mistakes
Fix some spelling mistakes in comments:
flaged ==> flagged
bufer ==> buffer
multipler ==> multiplier
MULTIPLER ==> MULTIPLIER
leaset ==> least
chnage ==> change

Link: https://lkml.kernel.org/r/20210604074401.12198-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Zhen Lei
05911c5d96 lib/decompressors: fix spelling mistakes
Fix some spelling mistakes in comments:
sentinal ==> sentinel
compresed ==> compressed
dependeny ==> dependency
immediatelly ==> immediately
dervied ==> derived
splitted ==> split
nore ==> not
independed ==> independent
asumed ==> assumed

Link: https://lkml.kernel.org/r/20210604085656.12257-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Trent Piepho
b6c75c4afc lib/math/rational: add Kunit test cases
Adds a number of test cases that cover a range of possible code paths.

[akpm@linux-foundation.org: remove non-ascii characters, fix whitespace]
[colin.king@canonical.com: fix spelling mistake "demominator" -> "denominator"]
  Link: https://lkml.kernel.org/r/20210526085049.6393-1-colin.king@canonical.com

Link: https://lkml.kernel.org/r/20210525144250.214670-2-tpiepho@gmail.com
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Oskar Schirmer <oskar@scara.com>
Cc: Yiyuan Guo <yguoaz@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Trent Piepho
65a0d3c146 lib/math/rational.c: fix divide by zero
If the input is out of the range of the allowed values, either larger than
the largest value or closer to zero than the smallest non-zero allowed
value, then a division by zero would occur.

In the case of input too large, the division by zero will occur on the
first iteration.  The best result (largest allowed value) will be found by
always choosing the semi-convergent and excluding the denominator based
limit when finding it.

In the case of the input too small, the division by zero will occur on the
second iteration.  The numerator based semi-convergent should not be
calculated to avoid the division by zero.  But the semi-convergent vs
previous convergent test is still needed, which effectively chooses
between 0 (the previous convergent) vs the smallest allowed fraction (best
semi-convergent) as the result.

Link: https://lkml.kernel.org/r/20210525144250.214670-1-tpiepho@gmail.com
Fixes: 323dd2c3ed ("lib/math/rational.c: fix possible incorrect result from rational fractions helper")
Signed-off-by: Trent Piepho <tpiepho@gmail.com>
Reported-by: Yiyuan Guo <yguoaz@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Oskar Schirmer <oskar@scara.com>
Cc: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00
Andy Shevchenko
cc72181a65 seq_file: drop unused *_escape_mem_ascii()
There are no more users of the seq_escape_mem_ascii() followed by
string_escape_mem_ascii().

Remove them for good.

Link: https://lkml.kernel.org/r/20210504180819.73127-16-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:05 -07:00