Commit Graph

38 Commits

Author SHA1 Message Date
Naveen N Rao
71db948b9d 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
2024-10-31 11:00:55 +11:00
Linus Torvalds
e5075d8ec5 Merge tag 'riscv-for-linus-6.8-mw4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull more RISC-V updates from Palmer Dabbelt:

 - Support for tuning for systems with fast misaligned accesses.

 - Support for SBI-based suspend.

 - Support for the new SBI debug console extension.

 - The T-Head CMOs now use PA-based flushes.

 - Support for enabling the V extension in kernel code.

 - Optimized IP checksum routines.

 - Various ftrace improvements.

 - Support for archrandom, which depends on the Zkr extension.

 - The build is no longer broken under NET=n, KUNIT=y for ports that
   don't define their own ipv6 checksum.

* tag 'riscv-for-linus-6.8-mw4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (56 commits)
  lib: checksum: Fix build with CONFIG_NET=n
  riscv: lib: Check if output in asm goto supported
  riscv: Fix build error on rv32 + XIP
  riscv: optimize ELF relocation function in riscv
  RISC-V: Implement archrandom when Zkr is available
  riscv: Optimize hweight API with Zbb extension
  riscv: add dependency among Image(.gz), loader(.bin), and vmlinuz.efi
  samples: ftrace: Add RISC-V support for SAMPLE_FTRACE_DIRECT[_MULTI]
  riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
  riscv: ftrace: Make function graph use ftrace directly
  riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
  lib/Kconfig.debug: Update AS_HAS_NON_CONST_LEB128 comment and name
  riscv: Restrict DWARF5 when building with LLVM to known working versions
  riscv: Hoist linker relaxation disabling logic into Kconfig
  kunit: Add tests for csum_ipv6_magic and ip_fast_csum
  riscv: Add checksum library
  riscv: Add checksum header
  riscv: Add static key for misaligned accesses
  asm-generic: Improve csum_fold
  RISC-V: selftests: cbo: Ensure asm operands match constraints
  ...
2024-01-20 11:06:04 -08:00
Song Shuai
629291dd84 samples: ftrace: Add RISC-V support for SAMPLE_FTRACE_DIRECT[_MULTI]
Add RISC-V variants of the ftrace-direct* samples.

Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20231130121531.1178502-5-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-17 18:17:10 -08:00
Steven Rostedt (Google)
d23569979c tracing: Allow creating instances with specified system events
A trace instance may only need to enable specific events. As the eventfs
directory of an instance currently creates all events which adds overhead,
allow internal instances to be created with just the events in systems
that they care about. This currently only deals with systems and not
individual events, but this should bring down the overhead of creating
instances for specific use cases quite bit.

The trace_array_get_by_name() now has another parameter "systems". This
parameter is a const string pointer of a comma/space separated list of
event systems that should be created by the trace_array. (Note if the
trace_array already exists, this parameter is ignored).

The list of systems is saved and if a module is loaded, its events will
not be added unless the system for those events also match the systems
string.

Link: https://lore.kernel.org/linux-trace-kernel/20231213093701.03fddec0@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Arun Easi   <aeasi@marvell.com>
Cc: Daniel Wagner <dwagner@suse.de>
Tested-by: Dmytro Maluka <dmaluka@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-12-18 23:14:16 -05:00
GONG, Ruiqi
e332938e6f samples: ftrace: Replace bti assembly with hint for older compiler
When cross-building the arm64 kernel with allmodconfig using GCC 9.4,
the following error occurs on multiple files under samples/ftrace/:

/tmp/ccPC1ODs.s: Assembler messages:
/tmp/ccPC1ODs.s:8: Error: selected processor does not support `bti c'

Fix this issue by replacing `bti c` with `hint 34`, which is compatible
for the older compiler.

Link: https://lore.kernel.org/linux-trace-kernel/20230820111509.1470826-1-gongruiqi@huaweicloud.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Florent Revest <revest@chromium.org>
Fixes: 8c3526fb86 ("arm64: ftrace: Add direct call trampoline samples support")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-21 22:03:58 -04:00
Florent Revest
8c3526fb86 arm64: ftrace: Add direct call trampoline samples support
The ftrace samples need per-architecture trampoline implementations
to save and restore argument registers around the calls to
my_direct_func* and to restore polluted registers (eg: x30).

These samples also include <asm/asm-offsets.h> which, on arm64, is not
necessary and redefines previously defined macros (resulting in
warnings) so these includes are guarded by !CONFIG_ARM64.

Link: https://lkml.kernel.org/r/20230427140700.625241-3-revest@chromium.org

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-07-10 17:51:54 -04:00
Florent Revest
8564c31587 samples: ftrace: Save required argument registers in sample trampolines
The ftrace-direct-too sample traces the handle_mm_fault function whose
signature changed since the introduction of the sample. Since:
commit bce617edec ("mm: do page fault accounting in handle_mm_fault")
handle_mm_fault now has 4 arguments. Therefore, the sample trampoline
should save 4 argument registers.

s390 saves all argument registers already so it does not need a change
but x86_64 needs an extra push and pop.

This also evolves the signature of the tracing function to make it
mirror the signature of the traced function.

Link: https://lkml.kernel.org/r/20230427140700.625241-2-revest@chromium.org

Cc: stable@vger.kernel.org
Fixes: bce617edec ("mm: do page fault accounting in handle_mm_fault")
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-07-10 17:50:41 -04:00
Linus Torvalds
611c9d8830 Merge tag 'loongarch-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
Pull LoongArch updates from Huacai Chen:

 - Better backtraces for humanization

 - Relay BCE exceptions to userland as SIGSEGV

 - Provide kernel fpu functions

 - Optimize memory ops (memset/memcpy/memmove)

 - Optimize checksum and crc32(c) calculation

 - Add ARCH_HAS_FORTIFY_SOURCE selection

 - Add function error injection support

 - Add ftrace with direct call support

 - Add basic perf tools support

* tag 'loongarch-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (24 commits)
  tools/perf: Add basic support for LoongArch
  LoongArch: ftrace: Add direct call trampoline samples support
  LoongArch: ftrace: Add direct call support
  LoongArch: ftrace: Implement ftrace_find_callable_addr() to simplify code
  LoongArch: ftrace: Fix build error if DYNAMIC_FTRACE_WITH_REGS is not set
  LoongArch: ftrace: Abstract DYNAMIC_FTRACE_WITH_ARGS accesses
  LoongArch: Add support for function error injection
  LoongArch: Add ARCH_HAS_FORTIFY_SOURCE selection
  LoongArch: crypto: Add crc32 and crc32c hw acceleration
  LoongArch: Add checksum optimization for 64-bit system
  LoongArch: Optimize memory ops (memset/memcpy/memmove)
  LoongArch: Provide kernel fpu functions
  LoongArch: Relay BCE exceptions to userland as SIGSEGV with si_code=SEGV_BNDERR
  LoongArch: Tweak the BADV and CPUCFG.PRID lines in show_regs()
  LoongArch: Humanize the ESTAT line when showing registers
  LoongArch: Humanize the ECFG line when showing registers
  LoongArch: Humanize the EUEN line when showing registers
  LoongArch: Humanize the PRMD line when showing registers
  LoongArch: Humanize the CRMD line when showing registers
  LoongArch: Fix format of CSR lines during show_regs()
  ...
2023-05-04 12:40:16 -07:00
Youling Tang
22f367a689 LoongArch: ftrace: Add direct call trampoline samples support
The ftrace samples need per-architecture trampoline implementations to
save and restore argument registers around the calls to my_direct_func*
and to restore polluted registers (e.g: ra).

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-05-01 17:19:53 +08:00
Florent Revest
da8bdfbd42 ftrace: Rename _ftrace_direct_multi APIs to _ftrace_direct APIs
Now that the original _ftrace_direct APIs are gone, the "_multi"
suffixes only add confusion.

Link: https://lkml.kernel.org/r/20230321140424.345218-5-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:43:32 -04:00
Florent Revest
23edf48309 ftrace: Replace uses of _ftrace_direct APIs with _ftrace_direct_multi
The _multi API requires that users keep their own ops but can enforce
that an op is only associated to one direct call.

Link: https://lkml.kernel.org/r/20230321140424.345218-3-revest@chromium.org

Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:42:12 -04:00
Florent Revest
59495740f7 ftrace: Let unregister_ftrace_direct_multi() call ftrace_free_filter()
A common pattern when using the ftrace_direct_multi API is to unregister
the ops and also immediately free its filter. We've noticed it's very
easy for users to miss calling ftrace_free_filter().

This adds a "free_filters" argument to unregister_ftrace_direct_multi()
to both remind the user they should free filters and also to make their
life easier.

Link: https://lkml.kernel.org/r/20230321140424.345218-2-revest@chromium.org

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21 13:42:11 -04:00
Tom Rix
aef70ebd62 samples: ftrace: Make some global variables static
smatch reports this representative issue
samples/ftrace/ftrace-ops.c:15:14: warning: symbol 'nr_function_calls' was not declared. Should it be static?

The nr_functions_calls and several other global variables are only
used in ftrace-ops.c, so they should be static.
Remove the instances of initializing static int to 0.

Link: https://lore.kernel.org/linux-trace-kernel/20230130193708.1378108-1-trix@redhat.com

Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-07 12:48:00 -05:00
Arnd Bergmann
f94fe7048a ftrace: sample: avoid open-coded 64-bit division
Calculating the average period requires a 64-bit division that leads
to a link failure on 32-bit architectures:

x86_64-linux-ld: samples/ftrace/ftrace-ops.o: in function `ftrace_ops_sample_init':
ftrace-ops.c:(.init.text+0x23b): undefined reference to `__udivdi3'

Use the div_u64() helper to do this instead. Since this is an init function that
is not called frequently, the runtime overhead is going to be acceptable.

Link: https://lore.kernel.org/linux-trace-kernel/20230130130246.247537-1-arnd@kernel.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: b56c68f705 ("ftrace: Add sample with custom ops")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-07 12:45:18 -05:00
Song Shuai
01678fbce3 samples: ftrace: Include the nospec-branch.h only for x86
When other architectures without the nospec functionality write their
direct-call functions of samples/ftrace/*.c, the including of
asm/nospec-branch.h must be taken care to fix the no header file found
error in building process.

This commit (ee3e2469b3 "x86/ftrace: Make it call depth tracking aware")
file-globally includes asm/nospec-branch.h providing CALL_DEPTH_ACCOUNT
for only x86 direct-call functions.

It seems better to move the including to `#ifdef CONFIG_X86_64`.

Link: https://lore.kernel.org/linux-trace-kernel/20230130085954.647845-1-suagrfillet@gmail.com

Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-07 12:44:39 -05:00
Mark Rutland
b56c68f705 ftrace: Add sample with custom ops
When reworking core ftrace code or architectural ftrace code, it's often
necessary to test/analyse/benchmark a number of ftrace_ops
configurations. This patch adds a module which can be used to explore
some of those configurations.

I'm using this to benchmark various options for changing the way
trampolines and handling of ftrace_ops work on arm64, and ensuring other
architectures aren't adversely affected.

For example, in a QEMU+KVM VM running on a 2GHz Xeon E5-2660
workstation, loading the module in various configurations produces:

| # insmod ftrace-ops.ko
| ftrace_ops: registering:
|   relevant ops: 1
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 0
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: NO
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1681558ns (16ns / call)

| # insmod ftrace-ops.ko nr_ops_irrelevant=5
| ftrace_ops: registering:
|   relevant ops: 1
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 5
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: NO
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1693042ns (16ns / call)

| # insmod ftrace-ops.ko nr_ops_relevant=2
| ftrace_ops: registering:
|   relevant ops: 2
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 0
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: NO
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 11965582ns (119ns / call)

| # insmod ftrace-ops.ko save_regs=true
| ftrace_ops: registering:
|   relevant ops: 1
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 0
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: YES
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 4459624ns (44ns / call)

Link: https://lkml.kernel.org/r/20230103124912.2948963-4-mark.rutland@arm.com

Cc: Florent Revest <revest@chromium.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-01-25 10:31:23 -05:00
Mark Rutland
8be9fbd534 ftrace: Export ftrace_free_filter() to modules
Setting filters on an ftrace ops results in some memory being allocated
for the filter hashes, which must be freed before the ops can be freed.
This can be done by removing every individual element of the hash by
calling ftrace_set_filter_ip() or ftrace_set_filter_ips() with `remove`
set, but this is somewhat error prone as it's easy to forget to remove
an element.

Make it easier to clean this up by exporting ftrace_free_filter(), which
can be used to clean up all of the filter hashes after an ftrace_ops has
been unregistered.

Using this, fix the ftrace-direct* samples to free hashes prior to being
unloaded. All other code either removes individual filters explicitly or
is built-in and already calls ftrace_free_filter().

Link: https://lkml.kernel.org/r/20230103124912.2948963-3-mark.rutland@arm.com

Cc: stable@vger.kernel.org
Cc: Florent Revest <revest@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: e1067a07cf ("ftrace/samples: Add module to test multi direct modify interface")
Fixes: 5fae941b9a ("ftrace/samples: Add multi direct interface test module")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-01-24 11:20:58 -05:00
Peter Zijlstra
ee3e2469b3 x86/ftrace: Make it call depth tracking aware
Since ftrace has trampolines, don't use thunks for the __fentry__ site
but instead require that every function called from there includes
accounting. This very much includes all the direct-call functions.

Additionally, ftrace uses ROP tricks in two places:

 - return_to_handler(), and
 - ftrace_regs_caller() when pt_regs->orig_ax is set by a direct-call.

return_to_handler() already uses a retpoline to replace an
indirect-jump to defeat IBT, since this is a jump-type retpoline, make
sure there is no accounting done and ALTERNATIVE the RET into a ret.

ftrace_regs_caller() does much the same and gets the same treatment.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111148.927545073@infradead.org
2022-10-17 16:41:19 +02:00
Peter Zijlstra
0aec21cfb5 x86/ibt,ftrace: Add ENDBR to samples/ftrace
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.523421433@infradead.org
2022-03-15 10:32:38 +01:00
Linus Torvalds
64ad946152 Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov:

 - Get rid of all the .fixup sections because this generates
   misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
   LIVEPATCH as the backtrace misses the function which is being fixed
   up.

 - Add Straight Line Speculation mitigation support which uses a new
   compiler switch -mharden-sls= which sticks an INT3 after a RET or an
   indirect branch in order to block speculation after them. Reportedly,
   CPUs do speculate behind such insns.

 - The usual set of cleanups and improvements

* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/entry_32: Fix segment exceptions
  objtool: Remove .fixup handling
  x86: Remove .fixup section
  x86/word-at-a-time: Remove .fixup usage
  x86/usercopy: Remove .fixup usage
  x86/usercopy_32: Simplify __copy_user_intel_nocache()
  x86/sgx: Remove .fixup usage
  x86/checksum_32: Remove .fixup usage
  x86/vmx: Remove .fixup usage
  x86/kvm: Remove .fixup usage
  x86/segment: Remove .fixup usage
  x86/fpu: Remove .fixup usage
  x86/xen: Remove .fixup usage
  x86/uaccess: Remove .fixup usage
  x86/futex: Remove .fixup usage
  x86/msr: Remove .fixup usage
  x86/extable: Extend extable functionality
  x86/entry_32: Remove .fixup usage
  x86/entry_64: Remove .fixup usage
  x86/copy_mc_64: Remove .fixup usage
  ...
2022-01-12 16:31:19 -08:00
Jiri Olsa
0daf5cb217 ftrace/samples: Add missing prototypes direct functions
There's another compilation fail (first here [1]) reported by kernel
test robot for W=1 clang build:

  >> samples/ftrace/ftrace-direct-multi-modify.c:7:6: warning: no previous
  prototype for function 'my_direct_func1' [-Wmissing-prototypes]
     void my_direct_func1(unsigned long ip)

Direct functions in ftrace direct sample modules need to have prototypes
defined. They are already global in order to be visible for the inline
assembly, so there's no problem.

The kernel test robot reported just error for ftrace-direct-multi-modify,
but I got same errors also for the rest of the modules touched by this patch.

[1] 67d4f6e3bf ftrace/samples: Add missing prototype for my_direct_func

Link: https://lkml.kernel.org/r/20211219135317.212430-1-jolsa@kernel.org

Reported-by: kernel test robot <lkp@intel.com>
Fixes: e1067a07cf ("ftrace/samples: Add module to test multi direct modify interface")
Fixes: ae0cc3b7e7 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()")
Fixes: 156473a0ff ("ftrace: Add another example of register_ftrace_direct() use case")
Fixes: b06457c83a ("ftrace: Add sample module that uses register_ftrace_direct()")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-05 18:34:50 -05:00
Jiri Olsa
e1067a07cf ftrace/samples: Add module to test multi direct modify interface
Adding ftrace-direct-multi-modify.ko kernel module that uses
modify_ftrace_direct_multi API. The core functionality is taken
from ftrace-direct-modify.ko kernel module and changed to fit
multi direct interface.

The init function creates kthread that periodically calls
modify_ftrace_direct_multi to change the trampoline address
for the direct ftrace_ops. The ftrace trace_pipe then shows
trace from both trampolines.

Link: https://lkml.kernel.org/r/20211206182032.87248-4-jolsa@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-09 13:02:44 -05:00
Peter Zijlstra
b17c2baa30 x86: Prepare inline-asm for straight-line-speculation
Replace all ret/retq instructions with ASM_RET in preparation of
making it more than a single instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.964635458@infradead.org
2021-12-08 19:23:12 +01:00
Heiko Carstens
890e3dc8bb ftrace/samples: add s390 support for ftrace direct multi sample
Add s390 architecture support for the ftrace direct multi sample.
See commit 5fae941b9a ("ftrace/samples: Add multi direct interface
test module") for further details.

Link: https://lore.kernel.org/r/20211115195614.3173346-3-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-18 17:50:54 +01:00
Heiko Carstens
503e451084 ftrace/samples: add missing Kconfig option for ftrace direct multi sample
Currently it is not possible to build the ftrace direct multi example
anymore due to broken config dependencies. Fix this by adding
SAMPLE_FTRACE_DIRECT_MULTI config option.

This broke when merging s390-5.16-1 due to an incorrect merge conflict
resolution proposed by me.

Also rename SAMPLE_FTRACE_MULTI_DIRECT to SAMPLE_FTRACE_DIRECT_MULTI
so it matches the module name.

Fixes: 0b707e572a ("Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211115195614.3173346-2-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-18 17:50:54 +01:00