The sc7180 lpass clock controller's pm_runtime usage wasn't broken
quite as spectacularly as the sc7280's pm_runtime usage, but it was
still broken. Putting some printouts in at boot showed me this (with
serial console enabled, which makes the prints slow and thus changes
timing):
[ 3.109951] DOUG: my_pm_clk_resume, usage=1
[ 3.114767] DOUG: my_pm_clk_resume, usage=1
[ 3.664443] DOUG: my_pm_clk_suspend, usage=0
[ 3.897566] DOUG: my_pm_clk_suspend, usage=0
[ 3.910137] DOUG: my_pm_clk_resume, usage=1
[ 3.923217] DOUG: my_pm_clk_resume, usage=0
[ 4.440116] DOUG: my_pm_clk_suspend, usage=-1
[ 4.444982] DOUG: my_pm_clk_suspend, usage=0
[ 14.170501] DOUG: my_pm_clk_resume, usage=1
[ 14.176245] DOUG: my_pm_clk_resume, usage=0
...or this w/out serial console:
[ 0.556139] DOUG: my_pm_clk_resume, usage=1
[ 0.556279] DOUG: my_pm_clk_resume, usage=1
[ 1.058422] DOUG: my_pm_clk_suspend, usage=-1
[ 1.058464] DOUG: my_pm_clk_suspend, usage=0
[ 1.186250] DOUG: my_pm_clk_resume, usage=1
[ 1.186292] DOUG: my_pm_clk_resume, usage=0
[ 1.731536] DOUG: my_pm_clk_suspend, usage=-1
[ 1.731557] DOUG: my_pm_clk_suspend, usage=0
[ 10.288910] DOUG: my_pm_clk_resume, usage=1
[ 10.289496] DOUG: my_pm_clk_resume, usage=0
It seems to be doing roughly the right sequence of calls, but just
like with sc7280 this is more by luck than anything. Having a usage of
-1 is just not OK.
Let's fix this like we did with sc7280.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Fixes: ce8c195e65 ("clk: qcom: lpasscc: Introduce pm autosuspend for SC7180")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221104064055.2.I49b25b9bda9430fc7ea21e5a708ca5a0aced2798@changeid
The pm_runtime usage in lpass-sc7280 was broken in quite a few
ways. Specifically:
1. At the end of probe it called "put" twice. This is a no-no and will
end us up with a negative usage count. Even worse than calling
"put" twice, it never called "get" once. Thus after bootup it could
be seen that the runtime usage of the devices managed by this
driver was -2.
2. In some error cases it manually called pm_runtime_disable() even
though it had previously used devm_add_action_or_reset() to set
this up to be called automatically. This meant that in these error
cases we'd double-call pm_runtime_disable().
3. It forgot to call undo pm_runtime_use_autosuspend(), which can
sometimes have subtle problems (and the docs specifically mention
that you need to undo this function).
Overall the above seriously calls into question how this driver is
working. It seems like a combination of "it doesn't", "by luck", and
"because of the weirdness of runtime_pm". Specifically I put a
printout to the serial console every time the runtime suspend/resume
was called for the two devices created by this driver (I wrapped the
pm_clk calls). When I had serial console enabled, I found that the
calls got resumed at bootup (when the clk core probed and before our
double-put) and then never touched again. That's no good.
[ 0.829997] DOUG: my_pm_clk_resume, usage=1
[ 0.835487] DOUG: my_pm_clk_resume, usage=1
When I disabled serial console (speeding up boot), I got a different
pattern, which I guess (?) is better:
[ 0.089767] DOUG: my_pm_clk_resume, usage=1
[ 0.090507] DOUG: my_pm_clk_resume, usage=1
[ 0.151885] DOUG: my_pm_clk_suspend, usage=-2
[ 0.151914] DOUG: my_pm_clk_suspend, usage=-2
[ 1.825747] DOUG: my_pm_clk_resume, usage=-1
[ 1.825774] DOUG: my_pm_clk_resume, usage=-1
[ 1.888269] DOUG: my_pm_clk_suspend, usage=-2
[ 1.888282] DOUG: my_pm_clk_suspend, usage=-2
These different patterns have to do with the fact that the core PM
Runtime code really isn't designed to be robust to negative usage
counts and sometimes may happen to stumble upon a behavior that
happens to "work". For instance, you can see that
__pm_runtime_suspend() will treat any non-zero value (including
negative numbers) as if the device is in use.
In any case, let's fix the driver to be correct. We'll hold a
pm_runtime reference for the whole probe and then drop it (once!) at
the end. We'll get rid of manual pm_runtime_disable() calls in the
error handling. We'll also switch to devm_pm_runtime_enable(), which
magically handles undoing pm_runtime_use_autosuspend() as of commit
b4060db925 ("PM: runtime: Have devm_pm_runtime_enable() handle
pm_runtime_dont_use_autosuspend()").
While we're at this, let's also use devm_pm_clk_create() instead of
rolling it ourselves.
Note that the above changes make it obvious that
lpassaudio_create_pm_clks() was doing more than just creating
clocks. It was also setting up pm_runtime parameters. Let's rename it.
All of these problems were found by code inspection. I started looking
at this driver because it was involved in a deadlock that I reported a
while ago [1]. Though I bisected the deadlock to commit 1b771839de
("clk: qcom: gdsc: enable optional power domain support"), it was
never really clear why that patch affected it other than a luck of
timing changes. I'll also note that by fixing the timing (as done in
this change) we also seem to aboid the deadlock, which is a nice
benefit.
Also note that some of the fixes here are much the same type of stuff
that Dmitry did in commit 72cfc73f46 ("clk: qcom: use
devm_pm_runtime_enable and devm_pm_clk_create"), but I guess
lpassaudiocc-sc7280.c didn't exist then.
[1] https://lore.kernel.org/r/20220922154354.2486595-1-dianders@chromium.org
Fixes: a9dd26639d ("clk: qcom: lpass: Add support for LPASS clock controller for SC7280")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221104064055.1.I00a0e4564a25489e85328ec41636497775627564@changeid
Pull more random number generator updates from Jason Donenfeld:
"This time with some large scale treewide cleanups.
The intent of this pull is to clean up the way callers fetch random
integers. The current rules for doing this right are:
- If you want a secure or an insecure random u64, use get_random_u64()
- If you want a secure or an insecure random u32, use get_random_u32()
The old function prandom_u32() has been deprecated for a while
now and is just a wrapper around get_random_u32(). Same for
get_random_int().
- If you want a secure or an insecure random u16, use get_random_u16()
- If you want a secure or an insecure random u8, use get_random_u8()
- If you want secure or insecure random bytes, use get_random_bytes().
The old function prandom_bytes() has been deprecated for a while
now and has long been a wrapper around get_random_bytes()
- If you want a non-uniform random u32, u16, or u8 bounded by a
certain open interval maximum, use prandom_u32_max()
I say "non-uniform", because it doesn't do any rejection sampling
or divisions. Hence, it stays within the prandom_*() namespace, not
the get_random_*() namespace.
I'm currently investigating a "uniform" function for 6.2. We'll see
what comes of that.
By applying these rules uniformly, we get several benefits:
- By using prandom_u32_max() with an upper-bound that the compiler
can prove at compile-time is ≤65536 or ≤256, internally
get_random_u16() or get_random_u8() is used, which wastes fewer
batched random bytes, and hence has higher throughput.
- By using prandom_u32_max() instead of %, when the upper-bound is
not a constant, division is still avoided, because
prandom_u32_max() uses a faster multiplication-based trick instead.
- By using get_random_u16() or get_random_u8() in cases where the
return value is intended to indeed be a u16 or a u8, we waste fewer
batched random bytes, and hence have higher throughput.
This series was originally done by hand while I was on an airplane
without Internet. Later, Kees and I worked on retroactively figuring
out what could be done with Coccinelle and what had to be done
manually, and then we split things up based on that.
So while this touches a lot of files, the actual amount of code that's
hand fiddled is comfortably small"
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
prandom: remove unused functions
treewide: use get_random_bytes() when possible
treewide: use get_random_u32() when possible
treewide: use get_random_{u8,u16}() when possible, part 2
treewide: use get_random_{u8,u16}() when possible, part 1
treewide: use prandom_u32_max() when possible, part 2
treewide: use prandom_u32_max() when possible, part 1
Pull more perf tools updates from Arnaldo Carvalho de Melo:
- Use BPF CO-RE (Compile Once, Run Everywhere) to support old kernels
when using bperf (perf BPF based counters) with cgroups.
- Support HiSilicon PCIe Performance Monitoring Unit (PMU), that
monitors bandwidth, latency, bus utilization and buffer occupancy.
Documented in Documentation/admin-guide/perf/hisi-pcie-pmu.rst.
- User space tasks can migrate between CPUs, so when tracing selected
CPUs, system-wide sideband is still needed, fix it in the setup of
Intel PT on hybrid systems.
- Fix metricgroups title message in 'perf list', it should state that
the metrics groups are to be used with the '-M' option, not '-e'.
- Sync the msr-index.h copy with the kernel sources, adding support for
using "AMD64_TSC_RATIO" in filter expressions in 'perf trace' as well
as decoding it when printing the MSR tracepoint arguments.
- Fix program header size and alignment when generating a JIT ELF in
'perf inject'.
- Add multiple new Intel PT 'perf test' entries, including a jitdump
one.
- Fix the 'perf test' entries for 'perf stat' CSV and JSON output when
running on PowerPC due to an invalid topology number in that arch.
- Fix the 'perf test' for arm_coresight failures on the ARM Juno
system.
- Fix the 'perf test' attr entry for PERF_FORMAT_LOST, adding this
option to the or expression expected in the intercepted
perf_event_open() syscall.
- Add missing condition flags ('hs', 'lo', 'vc', 'vs') for arm64 in the
'perf annotate' asm parser.
- Fix 'perf mem record -C' option processing, it was being chopped up
when preparing the underlying 'perf record -e mem-events' and thus
being ignored, requiring using '-- -C CPUs' as a workaround.
- Improvements and tidy ups for 'perf test' shell infra.
- Fix Intel PT information printing segfault in uClibc, where a NULL
format was being passed to fprintf.
* tag 'perf-tools-for-v6.1-2-2022-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (23 commits)
tools arch x86: Sync the msr-index.h copy with the kernel sources
perf auxtrace arm64: Add support for parsing HiSilicon PCIe Trace packet
perf auxtrace arm64: Add support for HiSilicon PCIe Tune and Trace device driver
perf auxtrace arm: Refactor event list iteration in auxtrace_record__init()
perf tests stat+json_output: Include sanity check for topology
perf tests stat+csv_output: Include sanity check for topology
perf intel-pt: Fix system_wide dummy event for hybrid
perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc
perf test: Fix attr tests for PERF_FORMAT_LOST
perf test: test_intel_pt.sh: Add 9 tests
perf inject: Fix GEN_ELF_TEXT_OFFSET for jit
perf test: test_intel_pt.sh: Add jitdump test
perf test: test_intel_pt.sh: Tidy some alignment
perf test: test_intel_pt.sh: Print a message when skipping kernel tracing
perf test: test_intel_pt.sh: Tidy some perf record options
perf test: test_intel_pt.sh: Fix return checking again
perf: Skip and warn on unknown format 'configN' attrs
perf list: Fix metricgroups title message
perf mem: Fix -C option behavior for perf mem record
perf annotate: Add missing condition flags for arm64
...
Pull Kbuild fixes from Masahiro Yamada:
- Fix CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y compile error for the
combination of Clang >= 14 and GAS <= 2.35.
- Drop vmlinux.bz2 from the rpm package as it just annoyingly increased
the package size.
- Fix modpost error under build environments using musl.
- Make *.ll files keep value names for easier debugging
- Fix single directory build
- Prevent RISC-V from selecting the broken DWARF5 support when Clang
and GAS are used together.
* tag 'kbuild-fixes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5
kbuild: fix single directory build
kbuild: add -fno-discard-value-names to cmd_cc_ll_c
scripts/clang-tools: Convert clang-tidy args to list
modpost: put modpost options before argument
kbuild: Stop including vmlinux.bz2 in the rpm's
Kconfig.debug: add toolchain checks for DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
Kconfig.debug: simplify the dependency of DEBUG_INFO_DWARF4/5
Pull more clk updates from Stephen Boyd:
"This is the final part of the clk patches for this merge window.
The clk rate range series needed another week to fully bake. Maxime
fixed the bug that broke clk notifiers and prevented this from being
included in the first pull request. He also added a unit test on top
to make sure it doesn't break so easily again. The majority of the
series fixes up how the clk_set_rate_*() APIs work, particularly
around when the rate constraints are dropped and how they move around
when reparenting clks. Overall it's a much needed improvement to the
clk rate range APIs that used to be pretty broken if you looked
sideways.
Beyond the core changes there are a few driver fixes for a compilation
issue or improper data causing clks to fail to register or have the
wrong parents. These are good to get in before the first -rc so that
the system actually boots on the affected devices"
* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (31 commits)
clk: tegra: Fix Tegra PWM parent clock
clk: at91: fix the build with binutils 2.27
clk: qcom: gcc-msm8660: Drop hardcoded fixed board clocks
clk: mediatek: clk-mux: Add .determine_rate() callback
clk: tests: Add tests for notifiers
clk: Update req_rate on __clk_recalc_rates()
clk: tests: Add missing test case for ranges
clk: qcom: clk-rcg2: Take clock boundaries into consideration for gfx3d
clk: Introduce the clk_hw_get_rate_range function
clk: Zero the clk_rate_request structure
clk: Stop forwarding clk_rate_requests to the parent
clk: Constify clk_has_parent()
clk: Introduce clk_core_has_parent()
clk: Switch from __clk_determine_rate to clk_core_round_rate_nolock
clk: Add our request boundaries in clk_core_init_rate_req
clk: Introduce clk_hw_init_rate_request()
clk: Move clk_core_init_rate_req() from clk_core_round_rate_nolock() to its caller
clk: Change clk_core_init_rate_req prototype
clk: Set req_rate on reparenting
clk: Take into account uncached clocks in clk_set_rate_range()
...
Pull more cifs updates from Steve French:
- fix a regression in guest mounts to old servers
- improvements to directory leasing (caching directory entries safely
beyond the root directory)
- symlink improvement (reducing roundtrips needed to process symlinks)
- an lseek fix (to problem where some dir entries could be skipped)
- improved ioctl for returning more detailed information on directory
change notifications
- clarify multichannel interface query warning
- cleanup fix (for better aligning buffers using ALIGN and round_up)
- a compounding fix
- fix some uninitialized variable bugs found by Coverity and the kernel
test robot
* tag '6.1-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
smb3: improve SMB3 change notification support
cifs: lease key is uninitialized in two additional functions when smb1
cifs: lease key is uninitialized in smb1 paths
smb3: must initialize two ACL struct fields to zero
cifs: fix double-fault crash during ntlmssp
cifs: fix static checker warning
cifs: use ALIGN() and round_up() macros
cifs: find and use the dentry for cached non-root directories also
cifs: enable caching of directories for which a lease is held
cifs: prevent copying past input buffer boundaries
cifs: fix uninitialised var in smb2_compound_op()
cifs: improve symlink handling for smb2+
smb3: clarify multichannel warning
cifs: fix regression in very old smb1 mounts
cifs: fix skipping to incorrect offset in emit_cached_dirents
When building with a RISC-V kernel with DWARF5 debug info using clang
and the GNU assembler, several instances of the following error appear:
/tmp/vgettimeofday-48aa35.s:2963: Error: non-constant .uleb128 is not supported
Dumping the .s file reveals these .uleb128 directives come from
.debug_loc and .debug_ranges:
.Ldebug_loc0:
.byte 4 # DW_LLE_offset_pair
.uleb128 .Lfunc_begin0-.Lfunc_begin0 # starting offset
.uleb128 .Ltmp1-.Lfunc_begin0 # ending offset
.byte 1 # Loc expr size
.byte 90 # DW_OP_reg10
.byte 0 # DW_LLE_end_of_list
.Ldebug_ranges0:
.byte 4 # DW_RLE_offset_pair
.uleb128 .Ltmp6-.Lfunc_begin0 # starting offset
.uleb128 .Ltmp27-.Lfunc_begin0 # ending offset
.byte 4 # DW_RLE_offset_pair
.uleb128 .Ltmp28-.Lfunc_begin0 # starting offset
.uleb128 .Ltmp30-.Lfunc_begin0 # ending offset
.byte 0 # DW_RLE_end_of_list
There is an outstanding binutils issue to support a non-constant operand
to .sleb128 and .uleb128 in GAS for RISC-V but there does not appear to
be any movement on it, due to concerns over how it would work with
linker relaxation.
To avoid these build errors, prevent DWARF5 from being selected when
using clang and an assembler that does not have support for these symbol
deltas, which can be easily checked in Kconfig with as-instr plus the
small test program from the dwz test suite from the binutils issue.
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
Link: https://github.com/ClangBuiltLinux/linux/issues/1719
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Commit f110e5a250 ("kbuild: refactor single builds of *.ko") was wrong.
KBUILD_MODULES _is_ needed for single builds.
Otherwise, "make foo/bar/baz/" does not build module objects at all.
Fixes: f110e5a250 ("kbuild: refactor single builds of *.ko")
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: David Sterba <dsterba@suse.com>
Pull slab hotfix from Vlastimil Babka:
"A single fix for the common-kmalloc series, for warnings on mips and
sparc64 reported by Guenter Roeck"
* tag 'slab-for-6.1-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm/slab: use kmalloc_node() for off slab freelist_idx_t array allocation
Pull OpenRISC updates from Stafford Horne:
"I have relocated to London so not much work from me while I get
settled.
Still, OpenRISC picked up two patches in this window:
- Fix for kernel page table walking from Jann Horn
- MAINTAINER entry cleanup from Palmer Dabbelt"
* tag 'for-linus' of https://github.com/openrisc/linux:
MAINTAINERS: git://github -> https://github.com for openrisc
openrisc: Fix pagewalk usage in arch_dma_{clear, set}_uncached
Pull pci fix from Bjorn Helgaas:
"Revert the attempt to distribute spare resources to unconfigured
hotplug bridges at boot time.
This fixed some dock hot-add scenarios, but Jonathan Cameron reported
that it broke a topology with a multi-function device where one
function was a Switch Upstream Port and the other was an Endpoint"
* tag 'pci-v6.1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
Revert "PCI: Distribute available resources for root buses, too"
After commit d6a71648db ("mm/slab: kmalloc: pass requests larger than
order-1 page to page allocator"), SLAB passes large ( > PAGE_SIZE * 2)
requests to buddy like SLUB does.
SLAB has been using kmalloc caches to allocate freelist_idx_t array for
off slab caches. But after the commit, freelist_size can be bigger than
KMALLOC_MAX_CACHE_SIZE.
Instead of using pointer to kmalloc cache, use kmalloc_node() and only
check if the kmalloc cache is off slab during calculate_slab_order().
If freelist_size > KMALLOC_MAX_CACHE_SIZE, no looping condition happens
as it allocates freelist_idx_t array directly from buddy.
Link: https://lore.kernel.org/all/20221014205818.GA1428667@roeck-us.net/
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: d6a71648db ("mm/slab: kmalloc: pass requests larger than order-1 page to page allocator")
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Change notification is a commonly supported feature by most servers,
but the current ioctl to request notification when a directory is
changed does not return the information about what changed
(even though it is returned by the server in the SMB3 change
notify response), it simply returns when there is a change.
This ioctl improves upon CIFS_IOC_NOTIFY by returning the notify
information structure which includes the name of the file(s) that
changed and why. See MS-SMB2 2.2.35 for details on the individual
filter flags and the file_notify_information structure returned.
To use this simply pass in the following (with enough space
to fit at least one file_notify_information structure)
struct __attribute__((__packed__)) smb3_notify {
uint32_t completion_filter;
bool watch_tree;
uint32_t data_len;
uint8_t data[];
} __packed;
using CIFS_IOC_NOTIFY_INFO 0xc009cf0b
or equivalently _IOWR(CIFS_IOCTL_MAGIC, 11, struct smb3_notify_info)
The ioctl will block until the server detects a change to that
directory or its subdirectories (if watch_tree is set).
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs_open and _cifsFileInfo_put also end up with lease_key uninitialized
in smb1 mounts. It is cleaner to set lease key to zero in these
places where leases are not supported (smb1 can not return lease keys
so the field was uninitialized).
Addresses-Coverity: 1514207 ("Uninitialized scalar variable")
Addresses-Coverity: 1514331 ("Uninitialized scalar variable")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
It is cleaner to set lease key to zero in the places where leases are not
supported (smb1 can not return lease keys so the field was uninitialized).
Addresses-Coverity: 1513994 ("Uninitialized scalar variable")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Coverity spotted that we were not initalizing Stbz1 and Stbz2 to
zero in create_sd_buf.
Addresses-Coverity: 1513848 ("Uninitialized scalar variable")
Cc: <stable@vger.kernel.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
The crash occurred because we were calling memzero_explicit() on an
already freed sess_data::iov[1] (ntlmsspblob) in sess_free_buffer().
Fix this by not calling memzero_explicit() on sess_data::iov[1] as
it's already by handled by callers.
Fixes: a4e430c8c8 ("cifs: replace kfree() with kfree_sensitive() for sensitive data")
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
To pick up the changes in:
b8d1d16360 ("x86/apic: Don't disable x2APIC if locked")
ca5b7c0d96 ("perf/x86/amd/lbr: Add LbrExtV2 branch record support")
Addressing these tools/perf build warnings:
diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
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'
That makes the beautification scripts to pick some new entries:
$ 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
--- before 2022-10-14 18:06:34.294561729 -0300
+++ after 2022-10-14 18:06:41.285744044 -0300
@@ -264,6 +264,7 @@
[0xc0000102 - x86_64_specific_MSRs_offset] = "KERNEL_GS_BASE",
[0xc0000103 - x86_64_specific_MSRs_offset] = "TSC_AUX",
[0xc0000104 - x86_64_specific_MSRs_offset] = "AMD64_TSC_RATIO",
+ [0xc000010e - x86_64_specific_MSRs_offset] = "AMD64_LBR_SELECT",
[0xc000010f - x86_64_specific_MSRs_offset] = "AMD_DBG_EXTN_CFG",
[0xc0000300 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS",
[0xc0000301 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_CTL",
$
Now one can trace systemwide asking to see backtraces to where that MSR
is being read/written, see this example with a previous update:
# perf trace -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB"
^C#
If we use -v (verbose mode) we can see what it does behind the scenes:
# perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB"
Using CPUID AuthenticAMD-25-21-0
0x6a0
0x6a8
New filter for msr:read_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313)
0x6a0
0x6a8
New filter for msr:write_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313)
mmap size 528384B
^C#
Example with a frequent msr:
# perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2
Using CPUID AuthenticAMD-25-21-0
0x48
New filter for msr:read_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841)
0x48
New filter for msr:write_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841)
mmap size 528384B
Looking at the vmlinux_path (8 entries long)
symsrc__init: build id mismatch for vmlinux.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
__switch_to_xtra ([kernel.kallsyms])
__switch_to ([kernel.kallsyms])
__schedule ([kernel.kallsyms])
schedule ([kernel.kallsyms])
futex_wait_queue_me ([kernel.kallsyms])
futex_wait ([kernel.kallsyms])
do_futex ([kernel.kallsyms])
__x64_sys_futex ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
entry_SYSCALL_64_after_hwframe ([kernel.kallsyms])
__futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so)
0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
__switch_to_xtra ([kernel.kallsyms])
__switch_to ([kernel.kallsyms])
__schedule ([kernel.kallsyms])
schedule_idle ([kernel.kallsyms])
do_idle ([kernel.kallsyms])
cpu_startup_entry ([kernel.kallsyms])
secondary_startup_64_no_verify ([kernel.kallsyms])
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/lkml/Y0nQkz2TUJxwfXJd@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
