Merge branch 'linus' into x86/mm, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull CRC updates from Eric Biggers:

- Reorganize the architecture-optimized CRC32 and CRC-T10DIF code to b

Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull CRC updates from Eric Biggers:

- Reorganize the architecture-optimized CRC32 and CRC-T10DIF code to be
directly accessible via the library API, instead of requiring the
crypto API. This is much simpler and more efficient.

- Convert some users such as ext4 to use the CRC32 library API instead
of the crypto API. More conversions like this will come later.

- Add a KUnit test that tests and benchmarks multiple CRC variants.
Remove older, less-comprehensive tests that are made redundant by
this.

- Add an entry to MAINTAINERS for the kernel's CRC library code. I'm
volunteering to maintain it. I have additional cleanups and
optimizations planned for future cycles.

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (31 commits)
MAINTAINERS: add entry for CRC library
powerpc/crc: delete obsolete crc-vpmsum_test.c
lib/crc32test: delete obsolete crc32test.c
lib/crc16_kunit: delete obsolete crc16_kunit.c
lib/crc_kunit.c: add KUnit test suite for CRC library functions
powerpc/crc-t10dif: expose CRC-T10DIF function through lib
arm64/crc-t10dif: expose CRC-T10DIF function through lib
arm/crc-t10dif: expose CRC-T10DIF function through lib
x86/crc-t10dif: expose CRC-T10DIF function through lib
crypto: crct10dif - expose arch-optimized lib function
lib/crc-t10dif: add support for arch overrides
lib/crc-t10dif: stop wrapping the crypto API
scsi: target: iscsi: switch to using the crc32c library
f2fs: switch to using the crc32 library
jbd2: switch to using the crc32c library
ext4: switch to using the crc32c library
lib/crc32: make crc32c() go directly to lib
bcachefs: Explicitly select CRYPTO from BCACHEFS_FS
x86/crc32: expose CRC32 functions through lib
x86/crc32: update prototype for crc32_pclmul_le_16()
...

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powerpc/crc-t10dif: expose CRC-T10DIF function through lib

Move the powerpc CRC-T10DIF assembly code into the lib directory and
wire it up to the library interface. This allows it to be used withou

powerpc/crc-t10dif: expose CRC-T10DIF function through lib

Move the powerpc CRC-T10DIF assembly code into the lib directory and
wire it up to the library interface. This allows it to be used without
going through the crypto API. It remains usable via the crypto API too
via the shash algorithms that use the library interface. Thus all the
arch-specific "shash" code becomes unnecessary and is removed.

Note: to see the diff from arch/powerpc/crypto/crct10dif-vpmsum_glue.c
to arch/powerpc/lib/crc-t10dif-glue.c, view this commit with
'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241202012056.209768-8-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

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powerpc/crc32: expose CRC32 functions through lib

Move the powerpc CRC32C assembly code into the lib directory and wire it
up to the library interface. This allows it to be used without going
throu

powerpc/crc32: expose CRC32 functions through lib

Move the powerpc CRC32C assembly code into the lib directory and wire it
up to the library interface. This allows it to be used without going
through the crypto API. It remains usable via the crypto API too via
the shash algorithms that use the library interface. Thus all the
arch-specific "shash" code becomes unnecessary and is removed.

Note: to see the diff from arch/powerpc/crypto/crc32c-vpmsum_glue.c to
arch/powerpc/lib/crc32-glue.c, view this commit with 'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20241202010844.144356-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

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Merge branch 'next' into for-linus

Prepare input updates for 6.14 merge window.

Merge tag 'v6.13-rc3' into next

Sync up with the mainline.

Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:

- Have fprobes built on top of function graph infrastructure

Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:

- Have fprobes built on top of function graph infrastructure

The fprobe logic is an optimized kprobe that uses ftrace to attach to
functions when a probe is needed at the start or end of the function.
The fprobe and kretprobe logic implements a similar method as the
function graph tracer to trace the end of the function. That is to
hijack the return address and jump to a trampoline to do the trace
when the function exits. To do this, a shadow stack needs to be
created to store the original return address. Fprobes and function
graph do this slightly differently. Fprobes (and kretprobes) has
slots per callsite that are reserved to save the return address. This
is fine when just a few points are traced. But users of fprobes, such
as BPF programs, are starting to add many more locations, and this
method does not scale.

The function graph tracer was created to trace all functions in the
kernel. In order to do this, when function graph tracing is started,
every task gets its own shadow stack to hold the return address that
is going to be traced. The function graph tracer has been updated to
allow multiple users to use its infrastructure. Now have fprobes be
one of those users. This will also allow for the fprobe and kretprobe
methods to trace the return address to become obsolete. With new
technologies like CFI that need to know about these methods of
hijacking the return address, going toward a solution that has only
one method of doing this will make the kernel less complex.

- Cleanup with guard() and free() helpers

There were several places in the code that had a lot of "goto out" in
the error paths to either unlock a lock or free some memory that was
allocated. But this is error prone. Convert the code over to use the
guard() and free() helpers that let the compiler unlock locks or free
memory when the function exits.

- Remove disabling of interrupts in the function graph tracer

When function graph tracer was first introduced, it could race with
interrupts and NMIs. To prevent that race, it would disable
interrupts and not trace NMIs. But the code has changed to allow NMIs
and also interrupts. This change was done a long time ago, but the
disabling of interrupts was never removed. Remove the disabling of
interrupts in the function graph tracer is it is not needed. This
greatly improves its performance.

- Allow the :mod: command to enable tracing module functions on the
kernel command line.

The function tracer already has a way to enable functions to be
traced in modules by writing ":mod:<module>" into set_ftrace_filter.
That will enable either all the functions for the module if it is
loaded, or if it is not, it will cache that command, and when the
module is loaded that matches <module>, its functions will be
enabled. This also allows init functions to be traced. But currently
events do not have that feature.

Because enabling function tracing can be done very early at boot up
(before scheduling is enabled), the commands that can be done when
function tracing is started is limited. Having the ":mod:" command to
trace module functions as they are loaded is very useful. Update the
kernel command line function filtering to allow it.

* tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
ftrace: Implement :mod: cache filtering on kernel command line
tracing: Adopt __free() and guard() for trace_fprobe.c
bpf: Use ftrace_get_symaddr() for kprobe_multi probes
ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr
Documentation: probes: Update fprobe on function-graph tracer
selftests/ftrace: Add a test case for repeating register/unregister fprobe
selftests: ftrace: Remove obsolate maxactive syntax check
tracing/fprobe: Remove nr_maxactive from fprobe
fprobe: Add fprobe_header encoding feature
fprobe: Rewrite fprobe on function-graph tracer
s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC
ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC
bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
tracing: Add ftrace_fill_perf_regs() for perf event
tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
fprobe: Use ftrace_regs in fprobe exit handler
fprobe: Use ftrace_regs in fprobe entry handler
fgraph: Pass ftrace_regs to retfunc
fgraph: Replace fgraph_ret_regs with ftrace_regs
...

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Merge tag 'powerpc-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Madhavan Srinivasan:

- Add preempt lazy support

- Deprecate cxl and cxl flash

Merge tag 'powerpc-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Madhavan Srinivasan:

- Add preempt lazy support

- Deprecate cxl and cxl flash driver

- Fix a possible IOMMU related OOPS at boot on pSeries

- Optimize sched_clock() in ppc32 by replacing mulhdu() by
mul_u64_u64_shr()

Thanks to Andrew Donnellan, Andy Shevchenko, Ankur Arora, Christophe
Leroy, Frederic Barrat, Gaurav Batra, Luis Felipe Hernandez, Michael
Ellerman, Nilay Shroff, Ricardo B. Marliere, Ritesh Harjani (IBM),
Sebastian Andrzej Siewior, Shrikanth Hegde, Sourabh Jain, Thorsten Blum,
and Zhu Jun.

* tag 'powerpc-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Fix argument order to timer_sub()
powerpc/prom_init: Use IS_ENABLED()
powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW
powerpc: Use str_on_off() helper in check_cache_coherency()
powerpc: Large user copy aware of full:rt:lazy preemption
powerpc: Add preempt lazy support
powerpc/book3s64/hugetlb: Fix disabling hugetlb when fadump is active
powerpc/vdso: Mark the vDSO code read-only after init
powerpc/64: Use get_user() in start_thread()
macintosh: declare ctl_table as const
selftest/powerpc/ptrace: Cleanup duplicate macro definitions
selftest/powerpc/ptrace/ptrace-pkey: Remove duplicate macros
selftest/powerpc/ptrace/core-pkey: Remove duplicate macros
powerpc/8xx: Drop legacy-of-mm-gpiochip.h header
scsi/cxlflash: Deprecate driver
cxl: Deprecate driver
selftests/powerpc: Fix typo in test-vphn.c
powerpc/xmon: Use str_yes_no() helper in dump_one_paca()
powerpc/32: Replace mulhdu() by mul_u64_u64_shr()

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Merge remote-tracking branch 'pm/opp/linux-next' into HEAD

Merge pm/opp tree to get dev_pm_opp_get_bw()

Signed-off-by: Rob Clark <robdclark@chromium.org>

ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC

Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func
macro check. This is for the other feature (e.g. FPROBE) which requires to
access

ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC

Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func
macro check. This is for the other feature (e.g. FPROBE) which requires to
access ftrace_regs from fgraph_ops::entryfunc() can avoid compiling if
the fgraph can not pass the valid ftrace_regs.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173519001472.391279.1174901685282588467.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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powerpc: Add preempt lazy support

Define preempt lazy bit for Powerpc. Use bit 9 which is free and within
16 bit range of NEED_RESCHED, so compiler can issue single andi.

Since Powerpc doesn't use

powerpc: Add preempt lazy support

Define preempt lazy bit for Powerpc. Use bit 9 which is free and within
16 bit range of NEED_RESCHED, so compiler can issue single andi.

Since Powerpc doesn't use the generic entry/exit, add lazy check at exit
to user. CONFIG_PREEMPTION is defined for lazy/full/rt so use it for
return to kernel.

Ran a few benchmarks and db workload on Power10. Performance is close to
preempt=none/voluntary.

Since Powerpc systems can have large core count and large memory,
preempt lazy is going to be helpful in avoiding soft lockup issues.

Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20241116192306.88217-2-sshegde@linux.ibm.com

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Merge drm/drm-next into drm-intel-next

Catching up with 6.13-rc2.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-xe-next

A backmerge to get the PMT preparation work for
merging the BMG PMT support.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-misc-next

Kickstart 6.14 cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge tag 'v6.13-rc1' into perf/core, to refresh the branch

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'asoc-fix-v6.13-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v6.13

A few small fixes for v6.13, all system specific - the biggest t

Merge tag 'asoc-fix-v6.13-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v6.13

A few small fixes for v6.13, all system specific - the biggest thing is
the fix for jack handling over suspend on some Intel laptops.

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Merge tag 'v6.12-rc3' into perf-tools-next

To get the fixes in the current perf-tools tree.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

- Rework kfence support for the HPT MMU to work on systems wit

Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

- Rework kfence support for the HPT MMU to work on systems with >= 16TB
of RAM.

- Remove the powerpc "maple" platform, used by the "Yellow Dog
Powerstation".

- Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines.

- Add support for running KVM nested guests on Power11.

- Other small features, cleanups and fixes.

Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa
Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert
Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard,
Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek,
Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao,
Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash,
Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen
Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum,
Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao.

* tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits)
EDAC/powerpc: Remove PPC_MAPLE drivers
powerpc/perf: Add per-task/process monitoring to vpa_pmu driver
powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch
docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu
powerpc/perf: Add perf interface to expose vpa counters
MAINTAINERS: powerpc: Mark Maddy as "M"
powerpc/Makefile: Allow overriding CPP
powerpc-km82xx.c: replace of_node_put() with __free
ps3: Correct some typos in comments
powerpc/kexec: Fix return of uninitialized variable
macintosh: Use common error handling code in via_pmu_led_init()
powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type()
powerpc: remove dead config options for MPC85xx platform support
powerpc/xive: Use cpumask_intersects()
selftests/powerpc: Remove the path after initialization.
powerpc/xmon: symbol lookup length fixed
powerpc/ep8248e: Use %pa to format resource_size_t
powerpc/ps3: Reorganize kerneldoc parameter names
KVM: PPC: Book3S HV: Fix kmv -> kvm typo
powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static
...

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samples/ftrace: Add support for ftrace direct samples on powerpc

Add powerpc 32-bit and 64-bit samples for ftrace direct. This serves to
show the sample instruction sequence to be used by ftrace dir

samples/ftrace: Add support for ftrace direct samples on powerpc

Add powerpc 32-bit and 64-bit samples for ftrace direct. This serves to
show the sample instruction sequence to be used by ftrace direct calls
to adhere to the ftrace ABI.

On 64-bit powerpc, TOC setup requires some additional work.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-17-hbathini@linux.ibm.com

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powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_DIRECT_CALLS

Add support for DYNAMIC_FTRACE_WITH_DIRECT_CALLS similar to the arm64
implementation.

ftrace direct calls allow custom trampolines t

powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_DIRECT_CALLS

Add support for DYNAMIC_FTRACE_WITH_DIRECT_CALLS similar to the arm64
implementation.

ftrace direct calls allow custom trampolines to be called into directly
from function ftrace call sites, bypassing the ftrace trampoline
completely. This functionality is currently utilized by BPF trampolines
to hook into kernel function entries.

Since we have limited relative branch range, we support ftrace direct
calls through support for DYNAMIC_FTRACE_WITH_CALL_OPS. In this
approach, ftrace trampoline is not entirely bypassed. Rather, it is
re-purposed into a stub that reads direct_call field from the associated
ftrace_ops structure and branches into that, if it is not NULL. For
this, it is sufficient if we can ensure that the ftrace trampoline is
reachable from all traceable functions.

When multiple ftrace_ops are associated with a call site, we utilize a
call back to set pt_regs->orig_gpr3 that can then be tested on the
return path from the ftrace trampoline to branch into the direct caller.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-16-hbathini@linux.ibm.com

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powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_CALL_OPS

Implement support for DYNAMIC_FTRACE_WITH_CALL_OPS similar to the
arm64 implementation.

This works by patching-in a pointer to an associ

powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_CALL_OPS

Implement support for DYNAMIC_FTRACE_WITH_CALL_OPS similar to the
arm64 implementation.

This works by patching-in a pointer to an associated ftrace_ops
structure before each traceable function. If multiple ftrace_ops are
associated with a call site, then a special ftrace_list_ops is used to
enable iterating over all the registered ftrace_ops. If no ftrace_ops
are associated with a call site, then a special ftrace_nop_ops structure
is used to render the ftrace call as a no-op. ftrace trampoline can then
read the associated ftrace_ops for a call site by loading from an offset
from the LR, and branch directly to the associated function.

The primary advantage with this approach is that we don't have to
iterate over all the registered ftrace_ops for call sites that have a
single ftrace_ops registered. This is the equivalent of implementing
support for dynamic ftrace trampolines, which set up a special ftrace
trampoline for each registered ftrace_ops and have individual call sites
branch into those directly.

A secondary advantage is that this gives us a way to add support for
direct ftrace callers without having to resort to using stubs. The
address of the direct call trampoline can be loaded from the ftrace_ops
structure.

To support this, we reserve a nop before each function on 32-bit
powerpc. For 64-bit powerpc, two nops are reserved before each
out-of-line stub. During ftrace activation, we update this location with
the associated ftrace_ops pointer. Then, on ftrace entry, we load from
this location and call into ftrace_ops->func().

For 64-bit powerpc, we ensure that the out-of-line stub area is
doubleword aligned so that ftrace_ops address can be updated atomically.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-15-hbathini@linux.ibm.com

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powerpc64/ftrace: Support .text larger than 32MB with out-of-line stubs

We are restricted to a .text size of ~32MB when using out-of-line
function profile sequence. Allow this to be extended up to t

powerpc64/ftrace: Support .text larger than 32MB with out-of-line stubs

We are restricted to a .text size of ~32MB when using out-of-line
function profile sequence. Allow this to be extended up to the previous
limit of ~64MB by reserving space in the middle of .text.

A new config option CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE is
introduced to specify the number of function stubs that are reserved in
.text. On boot, ftrace utilizes stubs from this area first before using
the stub area at the end of .text.

A ppc64le defconfig has ~44k functions that can be traced. A more
conservative value of 32k functions is chosen as the default value of
PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE so that we do not allot more space
than necessary by default. If building a kernel that only has 32k
trace-able functions, we won't allot any more space at the end of .text
during the pass on vmlinux.o. Otherwise, only the remaining functions
get space for stubs at the end of .text. This default value should help
cover a .text size of ~48MB in total (including space reserved at the
end of .text which can cover up to 32MB), which should be sufficient for
most common builds. For a very small kernel build, this can be set to 0.
Or, this can be bumped up to a larger value to support vmlinux .text
size up to ~64MB.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-14-hbathini@linux.ibm.com

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powerpc64/ftrace: Move ftrace sequence out of line

Function profile sequence on powerpc includes two instructions at the
beginning of each function:
mflr r0
bl ftrace_caller

The call to ftrace_ca

powerpc64/ftrace: Move ftrace sequence out of line

Function profile sequence on powerpc includes two instructions at the
beginning of each function:
mflr r0
bl ftrace_caller

The call to ftrace_caller() gets nop'ed out during kernel boot and is
patched in when ftrace is enabled.

Given the sequence, we cannot return from ftrace_caller with 'blr' as we
need to keep LR and r0 intact. This results in link stack (return
address predictor) imbalance when ftrace is enabled. To address that, we
would like to use a three instruction sequence:
mflr r0
bl ftrace_caller
mtlr r0

Further more, to support DYNAMIC_FTRACE_WITH_CALL_OPS, we need to
reserve two instruction slots before the function. This results in a
total of five instruction slots to be reserved for ftrace use on each
function that is traced.

Move the function profile sequence out-of-line to minimize its impact.
To do this, we reserve a single nop at function entry using
-fpatchable-function-entry=1 and add a pass on vmlinux.o to determine
the total number of functions that can be traced. This is then used to
generate a .S file reserving the appropriate amount of space for use as
ftrace stubs, which is built and linked into vmlinux.

On bootup, the stub space is split into separate stubs per function and
populated with the proper instruction sequence. A pointer to the
associated stub is maintained in dyn_arch_ftrace.

For modules, space for ftrace stubs is reserved from the generic module
stub space.

This is restricted to and enabled by default only on 64-bit powerpc,
though there are some changes to accommodate 32-bit powerpc. This is
done so that 32-bit powerpc could choose to opt into this based on
further tests and benchmarks.

As an example, after this patch, kernel functions will have a single nop
at function entry:
<kernel_clone>:
addis r2,r12,467
addi r2,r2,-16028
nop
mfocrf r11,8
...

When ftrace is enabled, the nop is converted to an unconditional branch
to the stub associated with that function:
<kernel_clone>:
addis r2,r12,467
addi r2,r2,-16028
b ftrace_ool_stub_text_end+0x11b28
mfocrf r11,8
...

The associated stub:
<ftrace_ool_stub_text_end+0x11b28>:
mflr r0
bl ftrace_caller
mtlr r0
b kernel_clone+0xc
...

This change showed an improvement of ~10% in null_syscall benchmark on a
Power 10 system with ftrace enabled.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-13-hbathini@linux.ibm.com

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powerpc/ftrace: Add a postlink script to validate function tracer

Function tracer on powerpc can only work with vmlinux having a .text
size of up to ~64MB due to powerpc branch instruction having a

powerpc/ftrace: Add a postlink script to validate function tracer

Function tracer on powerpc can only work with vmlinux having a .text
size of up to ~64MB due to powerpc branch instruction having a limited
relative branch range of 32MB. Today, this is only detected on kernel
boot when ftrace is init'ed. Add a post-link script to check the size of
.text so that we can detect this at build time, and break the build if
necessary.

We add a dependency on !COMPILE_TEST for CONFIG_HAVE_FUNCTION_TRACER so
that allyesconfig and other test builds can continue to work without
enabling ftrace.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-11-hbathini@linux.ibm.com

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powerpc: Fix stack protector Kconfig test for clang

Clang's in-progress per-task stack protector support [1] does not work
with the current Kconfig checks because '-mstack-protector-guard-offset'
is

powerpc: Fix stack protector Kconfig test for clang

Clang's in-progress per-task stack protector support [1] does not work
with the current Kconfig checks because '-mstack-protector-guard-offset'
is not provided, unlike all other architecture Kconfig checks.

$ fd Kconfig -x rg -l mstack-protector-guard-offset
./arch/arm/Kconfig
./arch/riscv/Kconfig
./arch/arm64/Kconfig

This produces an error from clang, which is interpreted as the flags not
being supported at all when they really are.

$ clang --target=powerpc64-linux-gnu \
-mstack-protector-guard=tls \
-mstack-protector-guard-reg=r13 \
-c -o /dev/null -x c /dev/null
clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default

This argument will always be provided by the build system, so mirror
other architectures and use '-mstack-protector-guard-offset=0' for
testing support, which fixes the issue for clang and does not regress
support with GCC.

Even with the first problem addressed, the 32-bit test continues to fail
because Kbuild uses the powerpc64le-linux-gnu target for clang and
nothing flips the target to 32-bit, resulting in an error about an
invalid register valid:

$ clang --target=powerpc64le-linux-gnu \
-mstack-protector-guard=tls
-mstack-protector-guard-reg=r2 \
-mstack-protector-guard-offset=0 \
-x c -c -o /dev/null /dev/null
clang: error: invalid value 'r2' in 'mstack-protector-guard-reg=', expected one of: r13

While GCC allows arbitrary registers, the implementation of
'-mstack-protector-guard=tls' in LLVM shares the same code path as the
user space thread local storage implementation, which uses a fixed
register (2 for 32-bit and 13 for 62-bit), so the command line parsing
enforces this limitation.

Use the Kconfig macro '$(m32-flag)', which expands to '-m32' when
supported, in the stack protector support cc-option call to properly
switch the target to a 32-bit one, which matches what happens in Kbuild.
While the 64-bit macro does not strictly need it, add the equivalent
64-bit option for symmetry.

Cc: stable@vger.kernel.org # 6.1+
Link: https://github.com/llvm/llvm-project/pull/110928 [1]
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241009-powerpc-fix-stackprotector-test-clang-v2-1-12fb86b31857@kernel.org

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