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>
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>
1, Better backtraces for humanization;
2, Relay BCE exceptions to userland as SIGSEGV;
3, Provide kernel fpu functions;
4, Optimize memory ops (memset/memcpy/memmove);
5, Optimize checksum and crc32(c) calculation;
6, Add ARCH_HAS_FORTIFY_SOURCE selection;
7, Add function error injection support;
8, Add ftrace with direct call support;
9, Add basic perf tools support.
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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()
...
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>
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>
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>
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>
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>
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
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>
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>
