| Age | Commit message (Collapse) | Author |
|---|
|
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
- Support for the FWFT SBI extension, which is part of SBI 3.0 and a
dependency for many new SBI and ISA extensions
- Support for getrandom() in the VDSO
- Support for mseal
- Optimized routines for raid6 syndrome and recovery calculations
- kexec_file() supports loading Image-formatted kernel binaries
- Improvements to the instruction patching framework to allow for
atomic instruction patching, along with rules as to how systems need
to behave in order to function correctly
- Support for a handful of new ISA extensions: Svinval, Zicbop, Zabha,
some SiFive vendor extensions
- Various fixes and cleanups, including: misaligned access handling,
perf symbol mangling, module loading, PUD THPs, and improved uaccess
routines
* tag 'riscv-for-linus-6.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (69 commits)
riscv: uaccess: Only restore the CSR_STATUS SUM bit
RISC-V: vDSO: Wire up getrandom() vDSO implementation
riscv: enable mseal sysmap for RV64
raid6: Add RISC-V SIMD syndrome and recovery calculations
riscv: mm: Add support for Svinval extension
RISC-V: Documentation: Add enough title underlines to CMODX
riscv: Improve Kconfig help for RISCV_ISA_V_PREEMPTIVE
MAINTAINERS: Update Atish's email address
riscv: uaccess: do not do misaligned accesses in get/put_user()
riscv: process: use unsigned int instead of unsigned long for put_user()
riscv: make unsafe user copy routines use existing assembly routines
riscv: hwprobe: export Zabha extension
riscv: Make regs_irqs_disabled() more clear
perf symbols: Ignore mapping symbols on riscv
RISC-V: Kconfig: Fix help text of CMDLINE_EXTEND
riscv: module: Optimize PLT/GOT entry counting
riscv: Add support for PUD THP
riscv: xchg: Prefetch the destination word for sc.w
riscv: Add ARCH_HAS_PREFETCH[W] support with Zicbop
riscv: Add support for Zicbop
...
|
|
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux into for-next
riscv patches for 6.16-rc1, part 2
* Performance improvements
- Add support for vdso getrandom
- Implement raid6 calculations using vectors
- Introduce svinval tlb invalidation
* Cleanup
- A bunch of deduplication of the macros we use for manipulating instructions
* Misc
- Introduce a kunit test for kprobes
- Add support for mseal as riscv fits the requirements (thanks to Lorenzo for making sure of that :))
[Palmer: There was a rebase between part 1 and part 2, so I've had to do
some more git surgery here... at least two rounds of surgery...]
* alex-pr-2: (866 commits)
RISC-V: vDSO: Wire up getrandom() vDSO implementation
riscv: enable mseal sysmap for RV64
raid6: Add RISC-V SIMD syndrome and recovery calculations
riscv: mm: Add support for Svinval extension
riscv: Add kprobes KUnit test
riscv: kprobes: Remove duplication of RV_EXTRACT_ITYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_UTYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_RD_REG
riscv: kprobes: Remove duplication of RVC_EXTRACT_BTYPE_IMM
riscv: kprobes: Remove duplication of RVC_EXTRACT_C2_RS1_REG
riscv: kproves: Remove duplication of RVC_EXTRACT_JTYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_BTYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_RS1_REG
riscv: kprobes: Remove duplication of RV_EXTRACT_JTYPE_IMM
riscv: kprobes: Move branch_funct3 to insn.h
riscv: kprobes: Move branch_rs2_idx to insn.h
Linux 6.15-rc6
Input: xpad - fix xpad_device sorting
Input: xpad - add support for several more controllers
Input: xpad - fix Share button on Xbox One controllers
...
|
|
The following ftrace patch for riscv uses a data store to update ftrace
function. Therefore, a romote fence is required to order it against
function_trace_op updates. The mechanism is similar to the fence between
function_trace_op and update_ftrace_func in the generic ftrace, so we
leverage the same ftrace_sync_ipi function.
[ alex: Fix build warning when !CONFIG_DYNAMIC_FTRACE ]
Signed-off-by: Andy Chiu <andybnac@gmail.com>
Link: https://lore.kernel.org/r/20250407180838.42877-4-andybnac@gmail.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
|
|
If ftrace is disabled, it is meaningless to allocate a module map.
Add a check in allocate_ftrace_mod_map() to not allocate if ftrace is
disabled.
Link: https://lore.kernel.org/20250529111955.2349189-3-yebin@huaweicloud.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The following issue happens with a buggy module:
BUG: unable to handle page fault for address: ffffffffc05d0218
PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
RIP: 0010:sized_strscpy+0x81/0x2f0
RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000
RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d
RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68
R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038
R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff
FS: 00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ftrace_mod_get_kallsym+0x1ac/0x590
update_iter_mod+0x239/0x5b0
s_next+0x5b/0xa0
seq_read_iter+0x8c9/0x1070
seq_read+0x249/0x3b0
proc_reg_read+0x1b0/0x280
vfs_read+0x17f/0x920
ksys_read+0xf3/0x1c0
do_syscall_64+0x5f/0x2e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The above issue may happen as follows:
(1) Add kprobe tracepoint;
(2) insmod test.ko;
(3) Module triggers ftrace disabled;
(4) rmmod test.ko;
(5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed;
ftrace_mod_get_kallsym()
...
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
...
The problem is when a module triggers an issue with ftrace and
sets ftrace_disable. The ftrace_disable is set when an anomaly is
discovered and to prevent any more damage, ftrace stops all text
modification. The issue that happened was that the ftrace_disable stops
more than just the text modification.
When a module is loaded, its init functions can also be traced. Because
kallsyms deletes the init functions after a module has loaded, ftrace
saves them when the module is loaded and function tracing is enabled. This
allows the output of the function trace to show the init function names
instead of just their raw memory addresses.
When a module is removed, ftrace_release_mod() is called, and if
ftrace_disable is set, it just returns without doing anything more. The
problem here is that it leaves the mod_list still around and if kallsyms
is called, it will call into this code and access the module memory that
has already been freed as it will return:
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
Where the "mod" no longer exists and triggers a UAF bug.
Link: https://lore.kernel.org/all/20250523135452.626d8dcd@gandalf.local.home/
Cc: stable@vger.kernel.org
Fixes: aba4b5c22cba ("ftrace: Save module init functions kallsyms symbols for tracing")
Link: https://lore.kernel.org/20250529111955.2349189-2-yebin@huaweicloud.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The structure ftrace_func_mapper only contains a single field and that is
a ftrace_hash. It is used to abstract it out from a normal hash to control
users of how it gets modified.
The freeing of a ftrace_func_mapper structure is:
free_ftrace_hash(&mapper->hash);
Without context, this looks like a bug. It should be commented that it is
not a bug and it is freed this way.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250416165420.5c717420@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The function graph infrastructure uses subops of the function tracer.
These are not shown in enabled_functions. Add a "subops:" section to the
enabled_functions line to show what functions are attached via subops. If
the subops is from the function_graph infrastructure, then show the entry
and return callbacks that are attached.
Here's an example of the output:
schedule_on_each_cpu (1) tramp: 0xffffffffc03ef000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops: {ent:trace_graph_entry+0x0/0x20 ret:trace_graph_return+0x0/0x150}
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250410153830.5d97f108@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The check for a failed memory location is incorrectly checking
the wrong level of pointer indirection by checking !filter_hash
rather than !*filter_hash. Fix this.
Cc: asami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250422221335.89896-1-colin.i.king@gmail.com
Fixes: 0ae6b8ce200d ("ftrace: Fix accounting of subop hashes")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The maximum of the ftrace hash bits is made fls(32) in
register_ftrace_direct(), which seems illogical. So, we fix it by making
the max hash bits FTRACE_HASH_MAX_BITS instead.
Link: https://lore.kernel.org/20250413014444.36724-1-dongml2@chinatelecom.cn
Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The subops processing creates new hashes when adding and removing subops.
There were some places that the old hashes that were replaced were not
freed and this caused some memory leaks.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250417135939.245b128d@gandalf.local.home
Fixes: 0ae6b8ce200d ("ftrace: Fix accounting of subop hashes")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
There's several locations that free a ftrace hash pointer but may be
referenced again. Reset them to EMPTY_HASH so that a u-a-f bug doesn't
happen.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250417110933.20ab718b@gandalf.local.home
Fixes: 0ae6b8ce200d ("ftrace: Fix accounting of subop hashes")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The reworking to fix and simplify the ftrace_startup_subops() and the
ftrace_shutdown_subops() made it possible for the filter_hash and
notrace_hash variables to be used uninitialized in a way that the compiler
did not catch it.
Initialize both filter_hash and notrace_hash to the EMPTY_HASH as that is
what they should be if they never are used.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250417104017.3aea66c2@gandalf.local.home
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Fixes: 0ae6b8ce200d ("ftrace: Fix accounting of subop hashes")
Closes: https://lore.kernel.org/all/1db64a42-626d-4b3a-be08-c65e47333ce2@linux.ibm.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The function graph infrastructure uses ftrace to hook to functions. It has
a single ftrace_ops to manage all the users of function graph. Each
individual user (tracing, bpf, fprobes, etc) has its own ftrace_ops to
track the functions it will have its callback called from. These
ftrace_ops are "subops" to the main ftrace_ops of the function graph
infrastructure.
Each ftrace_ops has a filter_hash and a notrace_hash that is defined as:
Only trace functions that are in the filter_hash but not in the
notrace_hash.
If the filter_hash is empty, it means to trace all functions.
If the notrace_hash is empty, it means do not disable any function.
The function graph main ftrace_ops needs to be a superset containing all
the functions to be traced by all the subops it has. The algorithm to
perform this merge was incorrect.
When the first subops was added to the main ops, it simply made the main
ops a copy of the subops (same filter_hash and notrace_hash).
When a second ops was added, it joined the new subops filter_hash with the
main ops filter_hash as a union of the two sets. The intersect between the
new subops notrace_hash and the main ops notrace_hash was created as the
new notrace_hash of the main ops.
The issue here is that it would then start tracing functions than no
subops were tracing. For example if you had two subops that had:
subops 1:
filter_hash = '*sched*' # trace all functions with "sched" in it
notrace_hash = '*time*' # except do not trace functions with "time"
subops 2:
filter_hash = '*lock*' # trace all functions with "lock" in it
notrace_hash = '*clock*' # except do not trace functions with "clock"
The intersect of '*time*' functions with '*clock*' functions could be the
empty set. That means the main ops will be tracing all functions with
'*time*' and all "*clock*" in it!
Instead, modify the algorithm to be a bit simpler and correct.
First, when adding a new subops, even if it's the first one, do not add
the notrace_hash if the filter_hash is not empty. Instead, just add the
functions that are in the filter_hash of the subops but not in the
notrace_hash of the subops into the main ops filter_hash. There's no
reason to add anything to the main ops notrace_hash.
The notrace_hash of the main ops should only be non empty iff all subops
filter_hashes are empty (meaning to trace all functions) and all subops
notrace_hashes include the same functions.
That is, the main ops notrace_hash is empty if any subops filter_hash is
non empty.
The main ops notrace_hash only has content in it if all subops
filter_hashes are empty, and the content are only functions that intersect
all the subops notrace_hashes. If any subops notrace_hash is empty, then
so is the main ops notrace_hash.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Andy Chiu <andybnac@gmail.com>
Link: https://lore.kernel.org/20250409152720.216356767@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The global notrace hash should be jointly decided by the intersection of
each subops's notrace hash, but not the filter hash.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com
Fixes: 5fccc7552ccb ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Andy Chiu <andybnac@gmail.com>
[ fixed removing of freeing of filter_hash ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When the kernel contains a large number of functions that can be traced,
the loop in ftrace_graph_set_hash() may take a lot of time to execute.
This may trigger the softlockup watchdog.
Add cond_resched() within the loop to allow the kernel to remain
responsive even when processing a large number of functions.
This matches the cond_resched() that is used in other locations of the
code that iterates over all functions that can be traced.
Cc: stable@vger.kernel.org
Fixes: b9b0c831bed26 ("ftrace: Convert graph filter to use hash tables")
Link: https://lore.kernel.org/tencent_3E06CE338692017B5809534B9C5C03DA7705@qq.com
Signed-off-by: zhoumin <teczm@foxmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the
function graph tracer (funcgraph-args) that when set, the tracers
will record the registers that hold the arguments into each function
event. On reading of the trace, it will use BTF to print those
arguments. Most archs support up to 6 arguments (depending on the
complexity of the arguments) and those are printed.
If a function has more arguments then what was recorded, the output
will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
* tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Use hashtable.h for event_hash
tracing: Fix use-after-free in print_graph_function_flags during tracer switching
function_graph: Remove the unused variable func
ftrace: Add arguments to function tracer
ftrace: Have funcgraph-args take affect during tracing
ftrace: Add support for function argument to graph tracer
ftrace: Add print_function_args()
ftrace: Have ftrace_free_filter() WARN and exit if ops is active
fgraph: Correct typo in ftrace_return_to_handler comment
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing / sorttable updates from Steven Rostedt:
- Implement arm64 build time sorting of the mcount location table
When gcc is used to build arm64, the mcount_loc section is all zeros
in the vmlinux elf file. The addresses are stored in the Elf_Rela
location.
To sort at build time, an array is allocated and the addresses are
added to it via the content of the mcount_loc section as well as he
Elf_Rela data. After sorting, the information is put back into the
Elf_Rela which now has the section sorted.
- Make sorting of mcount location table for arm64 work with clang as
well
When clang is used, the mcount_loc section contains the addresses,
unlike the gcc build. An array is still created and the sorting works
for both methods.
- Remove weak functions from the mcount_loc section
Have the sorttable code pass in the data of functions defined via
'nm -S' which shows the functions as well as their sizes. Using this
information the sorttable code can determine if a function in the
mcount_loc section was weak and overridden. If the function is not
found, it is set to be zero. On boot, when the mcount_loc section is
read and the ftrace table is created, if the address in the
mcount_loc is not in the kernel core text then it is removed and not
added to the ftrace_filter_functions (the functions that can be
attached by ftrace callbacks).
- Update and fix the reporting of how much data is used for ftrace
functions
On boot, a report of how many pages were used by the ftrace table as
well as how they were grouped (the table holds a list of sections
that are groups of pages that were able to be allocated). The
removing of the weak functions required the accounting to be updated.
* tag 'trace-sorttable-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
scripts/sorttable: Allow matches to functions before function entry
scripts/sorttable: Use normal sort if theres no relocs in the mcount section
ftrace: Check against is_kernel_text() instead of kaslr_offset()
ftrace: Test mcount_loc addr before calling ftrace_call_addr()
ftrace: Have ftrace pages output reflect freed pages
ftrace: Update the mcount_loc check of skipped entries
scripts/sorttable: Zero out weak functions in mcount_loc table
scripts/sorttable: Always use an array for the mcount_loc sorting
scripts/sorttable: Have mcount rela sort use direct values
arm64: scripts/sorttable: Implement sorting mcount_loc at boot for arm64
|
|
The ftrace_free_filter() is used to reset the ops filters. But it must be
done if the ops is not currently active (tracing). If it is, it will mess
up the ftrace accounting of what functions are attached and what is not.
WARN and exit the ftrace_free_filter() if the ops is active when it is
called.
Currently, it doesn't seem if anything does this, but it may in the
future.
Link: https://lore.kernel.org/all/20250219095330.2e9f171c@gandalf.local.home/
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250219135040.3a9fbe00@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64}
produce zero and skip stddev computation in that case.
For now don't care about rec->counter * rec->counter overflow because
rec->time * rec->time overflow will likely happen earlier.
Cc: stable@vger.kernel.org
Cc: Wen Yang <wenyang@linux.alibaba.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250206090156.1561783-1-kniv@yandex-team.ru
Fixes: e31f7939c1c27 ("ftrace: Avoid potential division by zero in function profiler")
Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
As kaslr_offset() is architecture dependent and also may not be defined by
all architectures, when zeroing out unused weak functions, do not check
against kaslr_offset(), but instead check if the address is within the
kernel text sections. If KASLR added a shift to the zeroed out function,
it would still not be located in the kernel text. This is a more robust
way to test if the text is valid or not.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Arnd Bergmann" <arnd@arndb.de>
Link: https://lore.kernel.org/20250225182054.471759017@goodmis.org
Fixes: ef378c3b8233 ("scripts/sorttable: Zero out weak functions in mcount_loc table")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Mark Brown <broonie@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20250224180805.GA1536711@ax162/
Closes: https://lore.kernel.org/all/5225b07b-a9b2-4558-9d5f-aa60b19f6317@sirena.org.uk/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The addresses in the mcount_loc can be zeroed and then moved by KASLR
making them invalid addresses. ftrace_call_addr() for ARM 64 expects a
valid address to kernel text. If the addr read from the mcount_loc section
is invalid, it must not call ftrace_call_addr(). Move the addr check
before calling ftrace_call_addr() in ftrace_process_locs().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/20250225182054.290128736@goodmis.org
Fixes: ef378c3b8233 ("scripts/sorttable: Zero out weak functions in mcount_loc table")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: "Arnd Bergmann" <arnd@arndb.de>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20250225025631.GA271248@ax162/
Closes: https://lore.kernel.org/all/91523154-072b-437b-bbdc-0b70e9783fd0@app.fastmail.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Check if a function is already in the manager ops of a subops. A manager
ops contains multiple subops, and if two or more subops are tracing the
same function, the manager ops only needs a single entry in its hash.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.226762894@goodmis.org
Fixes: 4f554e955614f ("ftrace: Add ftrace_set_filter_ips function")
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Function graph uses a subops and manager ops mechanism to attach to
ftrace. The manager ops connects to ftrace and the functions it connects
to is defined by a list of subops that it manages.
The function hash that defines what the above ops attaches to limits the
functions to attach if the hash has any content. If the hash is empty, it
means to trace all functions.
The creation of the manager ops hash is done by iterating over all the
subops hashes. If any of the subops hashes is empty, it means that the
manager ops hash must trace all functions as well.
The issue is in the creation of the manager ops. When a second subops is
attached, a new hash is created by starting it as NULL and adding the
subops one at a time. But the NULL ops is mistaken as an empty hash, and
once an empty hash is found, it stops the loop of subops and just enables
all functions.
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
try_to_run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
cleanup_rapl_pmus (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_free_pcibus_map (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_types_exit (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
kvm_shutdown (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_dump_msrs (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_cleanup_l1d_flush (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
[..]
Fix this by initializing the new hash to NULL and if the hash is NULL do
not treat it as an empty hash but instead allocate by copying the content
of the first sub ops. Then on subsequent iterations, the new hash will not
be NULL, but the content of the previous subops. If that first subops
attached to all functions, then new hash may assume that the manager ops
also needs to attach to all functions.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.060300046@goodmis.org
Fixes: 5fccc7552ccbc ("ftrace: Add subops logic to allow one ops to manage many")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The amount of memory that ftrace uses to save the descriptors to manage
the functions it can trace is shown at output. But if there are a lot of
functions that are skipped because they were weak or the architecture
added holes into the tables, then the extra pages that were allocated are
freed. But these freed pages are not reflected in the numbers shown, and
they can even be inconsistent with what is reported:
ftrace: allocating 57482 entries in 225 pages
ftrace: allocated 224 pages with 3 groups
The above shows the number of original entries that are in the mcount_loc
section and the pages needed to save them (225), but the second output
reflects the number of pages that were actually used. The two should be
consistent as:
ftrace: allocating 56739 entries in 224 pages
ftrace: allocated 224 pages with 3 groups
The above also shows the accurate number of entires that were actually
stored and does not include the entries that were removed.
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200023.221100846@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Now that weak functions turn into skipped entries, update the check to
make sure the amount that was allocated would fit both the entries that
were allocated as well as those that were skipped.
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200023.055162048@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.
Created this by running an spatch followed by a sed command:
Spatch:
virtual patch
@
depends on !(file in "net")
disable optional_qualifier
@
identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@
+ const
struct ctl_table table_name [] = { ... };
sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- 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.
- Update the Rust tracepoint code to use the C code too
There was some duplication of the tracepoint code for Rust that did
the same logic as the C code. Add a helper that makes it possible for
both algorithms to use the same logic in one place.
- Add poll to trace event hist files
It is useful to know when an event is triggered, or even with some
filtering. Since hist files of events get updated when active and the
event is triggered, allow applications to poll the hist file and wake
up when an event is triggered. This will let the application know
that the event it is waiting for happened.
- Add :mod: command to enable events for current or future modules
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.
Add the command where if ':mod:<module>' is written into set_event,
then either all the modules events are enabled if it is loaded, or
cache it so that the module's events are enabled when it is loaded.
This also works from the kernel command line, where
"trace_event=:mod:<module>", when the module is loaded at boot up,
its events will be enabled then.
* tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
tracing: Fix output of set_event for some cached module events
tracing: Fix allocation of printing set_event file content
tracing: Rename update_cache() to update_mod_cache()
tracing: Fix #if CONFIG_MODULES to #ifdef CONFIG_MODULES
selftests/ftrace: Add test that tests event :mod: commands
tracing: Cache ":mod:" events for modules not loaded yet
tracing: Add :mod: command to enabled module events
selftests/tracing: Add hist poll() support test
tracing/hist: Support POLLPRI event for poll on histogram
tracing/hist: Add poll(POLLIN) support on hist file
tracing: Fix using ret variable in tracing_set_tracer()
tracepoint: Reduce duplication of __DO_TRACE_CALL
tracing/string: Create and use __free(argv_free) in trace_dynevent.c
tracing: Switch trace_stat.c code over to use guard()
tracing: Switch trace_stack.c code over to use guard()
tracing: Switch trace_osnoise.c code over to use guard() and __free()
tracing: Switch trace_events_synth.c code over to use guard()
tracing: Switch trace_events_filter.c code over to use guard()
tracing: Switch trace_events_trigger.c code over to use guard()
tracing: Switch trace_events_hist.c code over to use guard()
...
|
|
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
...
|
|
Module functions can be set to set_ftrace_filter before the module is
loaded.
# echo :mod:snd_hda_intel > set_ftrace_filter
This will enable all the functions for the module snd_hda_intel. If that
module is not loaded, it is "cached" in the trace array for when the
module is loaded, its functions will be traced.
But this is not implemented in the kernel command line. That's because the
kernel command line filtering is added very early in boot up as it is
needed to be done before boot time function tracing can start, which is
also available very early in boot up. The code used by the
"set_ftrace_filter" file can not be used that early as it depends on some
other initialization to occur first. But some of the functions can.
Implement the ":mod:" feature of "set_ftrace_filter" in the kernel command
line parsing. Now function tracing on just a single module that is loaded
at boot up can be done.
Adding:
ftrace=function ftrace_filter=:mod:sna_hda_intel
To the kernel command line will only enable the sna_hda_intel module
functions when the module is loaded, and it will start tracing.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250116175832.34e39779@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When the :mod: command is written into /sys/kernel/tracing/set_event (or
that file within an instance), if the module specified after the ":mod:"
is not yet loaded, it will store that string internally. When the module
is loaded, it will enable the events as if the module was loaded when the
string was written into the set_event file.
This can also be useful to enable events that are in the init section of
the module, as the events are enabled before the init section is executed.
This also works on the kernel command line:
trace_event=:mod:<module>
Will enable the events for <module> when it is loaded.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250116143533.514730995@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Commit c132be2c4fcc ("function_graph: Have the instances use their own
ftrace_ops for filtering"), function profiler (enabled via
function_profile_enabled) has been showing statistics for all functions,
ignoring set_ftrace_filter settings.
While tracers are instantiated, the function profiler is not. Therefore, it
should use the global set_ftrace_filter for consistency. This patch
modifies the function profiler to use the global filter, fixing the
filtering functionality.
Before (filtering not working):
```
root@localhost:~# echo 'vfs*' > /sys/kernel/tracing/set_ftrace_filter
root@localhost:~# echo 1 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# sleep 1
root@localhost:~# echo 0 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# head /sys/kernel/tracing/trace_stat/*
Function Hit Time Avg
s^2
-------- --- ---- ---
---
schedule 314 22290594 us 70989.15 us
40372231 us
x64_sys_call 1527 8762510 us 5738.382 us
3414354 us
schedule_hrtimeout_range 176 8665356 us 49234.98 us
405618876 us
__x64_sys_ppoll 324 5656635 us 17458.75 us
19203976 us
do_sys_poll 324 5653747 us 17449.83 us
19214945 us
schedule_timeout 67 5531396 us 82558.15 us
2136740827 us
__x64_sys_pselect6 12 3029540 us 252461.7 us
63296940171 us
do_pselect.constprop.0 12 3029532 us 252461.0 us
63296952931 us
```
After (filtering working):
```
root@localhost:~# echo 'vfs*' > /sys/kernel/tracing/set_ftrace_filter
root@localhost:~# echo 1 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# sleep 1
root@localhost:~# echo 0 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# head /sys/kernel/tracing/trace_stat/*
Function Hit Time Avg
s^2
-------- --- ---- ---
---
vfs_write 462 68476.43 us 148.217 us
25874.48 us
vfs_read 641 9611.356 us 14.994 us
28868.07 us
vfs_fstat 890 878.094 us 0.986 us
1.667 us
vfs_fstatat 227 757.176 us 3.335 us
18.928 us
vfs_statx 226 610.610 us 2.701 us
17.749 us
vfs_getattr_nosec 1187 460.919 us 0.388 us
0.326 us
vfs_statx_path 297 343.287 us 1.155 us
11.116 us
vfs_rename 6 291.575 us 48.595 us
9889.236 us
```
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250101190820.72534-1-enjuk@amazon.com
Fixes: c132be2c4fcc ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Pass ftrace_regs to the fgraph_ops::retfunc(). If ftrace_regs is not
available, it passes a NULL instead. User callback function can access
some registers (including return address) via this ftrace_regs.
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>
Link: https://lore.kernel.org/173518992972.391279.14055405490327765506.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not
available, it passes a NULL instead. User callback function can access
some registers (including return address) via this ftrace_regs.
Note that the ftrace_regs can be NULL when the arch does NOT define:
HAVE_DYNAMIC_FTRACE_WITH_ARGS or HAVE_DYNAMIC_FTRACE_WITH_REGS.
More specifically, if HAVE_DYNAMIC_FTRACE_WITH_REGS is defined but
not the HAVE_DYNAMIC_FTRACE_WITH_ARGS, and the ftrace ops used to
register the function callback does not set FTRACE_OPS_FL_SAVE_REGS.
In this case, ftrace_regs can be NULL in user callback.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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: Catalin Marinas <catalin.marinas@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/173518990044.391279.17406984900626078579.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
There are a few functions in ftrace.c that have "goto out" or equivalent
on error in order to release locks that were taken. This can be error
prone or just simply make the code more complex.
Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.718001540@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
There are some goto jumps to exit a program to just return a value. The
code after the label doesn't free anything nor does it do any unlocks. It
simply returns the variable that was set before the jump.
Remove these unneeded goto jumps.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.544855549@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The function profiler disables interrupts before processing. This was
there since the profiler was introduced back in 2009 when there were
recursion issues to deal with. The function tracer is much more robust
today and has its own internal recursion protection. There's no reason to
disable interrupts in the function profiler.
Instead, just disable preemption and use the guard() infrastructure while
at it.
Before this change:
~# echo 1 > /sys/kernel/tracing/function_profile_enabled
~# perf stat -r 10 ./hackbench 10
Time: 3.099
Time: 2.556
Time: 2.500
Time: 2.705
Time: 2.985
Time: 2.959
Time: 2.859
Time: 2.621
Time: 2.742
Time: 2.631
Performance counter stats for '/work/c/hackbench 10' (10 runs):
23,156.77 msec task-clock # 6.951 CPUs utilized ( +- 2.36% )
18,306 context-switches # 790.525 /sec ( +- 5.95% )
495 cpu-migrations # 21.376 /sec ( +- 8.61% )
11,522 page-faults # 497.565 /sec ( +- 1.80% )
47,967,124,606 cycles # 2.071 GHz ( +- 0.41% )
80,009,078,371 instructions # 1.67 insn per cycle ( +- 0.34% )
16,389,249,798 branches # 707.752 M/sec ( +- 0.36% )
139,943,109 branch-misses # 0.85% of all branches ( +- 0.61% )
3.332 +- 0.101 seconds time elapsed ( +- 3.04% )
After this change:
~# echo 1 > /sys/kernel/tracing/function_profile_enabled
~# perf stat -r 10 ./hackbench 10
Time: 1.869
Time: 1.428
Time: 1.575
Time: 1.569
Time: 1.685
Time: 1.511
Time: 1.611
Time: 1.672
Time: 1.724
Time: 1.715
Performance counter stats for '/work/c/hackbench 10' (10 runs):
13,578.21 msec task-clock # 6.931 CPUs utilized ( +- 2.23% )
12,736 context-switches # 937.973 /sec ( +- 3.86% )
341 cpu-migrations # 25.114 /sec ( +- 5.27% )
11,378 page-faults # 837.960 /sec ( +- 1.74% )
27,638,039,036 cycles # 2.035 GHz ( +- 0.27% )
45,107,762,498 instructions # 1.63 insn per cycle ( +- 0.23% )
8,623,868,018 branches # 635.125 M/sec ( +- 0.27% )
125,738,443 branch-misses # 1.46% of all branches ( +- 0.32% )
1.9590 +- 0.0484 seconds time elapsed ( +- 2.47% )
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.373853944@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Addition of faultable tracepoints
There's a tracepoint attached to both a system call entry and exit.
This location is known to allow page faults. The tracepoints are
called under an rcu_read_lock() which does not allow faults that can
sleep. This limits the ability of tracepoint handlers to page fault
in user space system call parameters. Now these tracepoints have been
made "faultable", allowing the callbacks to fault in user space
parameters and record them.
Note, only the infrastructure has been implemented. The consumers
(perf, ftrace, BPF) now need to have their code modified to allow
faults.
- Fix up of BPF code for the tracepoint faultable logic
- Update tracepoints to use the new static branch API
- Remove trace_*_rcuidle() variants and the SRCU protection they used
- Remove unused TRACE_EVENT_FL_FILTERED logic
- Replace strncpy() with strscpy() and memcpy()
- Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()
- Fix perf events to not duplicate samples when tracing is enabled
- Replace atomic64_add_return(1, counter) with
atomic64_inc_return(counter)
- Make stack trace buffer 4K instead of PAGE_SIZE
- Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used
- Get the true return address for function tracer when function graph
tracer is also running.
When function_graph trace is running along with function tracer, the
parent function of the function tracer sometimes is
"return_to_handler", which is the function graph trampoline to record
the exit of the function. Use existing logic that calls into the
fgraph infrastructure to find the real return address.
- Remove (un)regfunc pointers out of tracepoint structure
- Added last minute bug fix for setting pending modules in stack
function filter.
echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
Would cause a kernel NULL dereference.
- Minor clean ups
* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
ftrace: Fix regression with module command in stack_trace_filter
tracing: Fix function name for trampoline
ftrace: Get the true parent ip for function tracer
tracing: Remove redundant check on field->field in histograms
bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
bpf: decouple BPF link/attach hook and BPF program sleepable semantics
bpf: put bpf_link's program when link is safe to be deallocated
tracing: Replace strncpy() with strscpy() when copying comm
tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
tracing: Fix syscall tracepoint use-after-free
tracing: Introduce tracepoint_is_faultable()
tracing: Introduce tracepoint extended structure
tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
tracing: Replace multiple deprecated strncpy with memcpy
tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
tracing: Use atomic64_inc_return() in trace_clock_counter()
trace/trace_event_perf: remove duplicate samples on the first tracepoint event
tracing/bpf: Add might_fault check to syscall probes
tracing/perf: Add might_fault check to syscall probes
tracing/ftrace: Add might_fault check to syscall probes
...
|
|
When executing the following command:
# echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
The current mod command causes a null pointer dereference. While commit
0f17976568b3f ("ftrace: Fix regression with module command in stack_trace_filter")
has addressed part of the issue, it left a corner case unhandled, which still
results in a kernel crash.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241120052750.275463-1-guoweikang.kernel@gmail.com
Fixes: 04ec7bb642b77 ("tracing: Have the trace_array hold the list of registered func probes");
Signed-off-by: guoweikang <guoweikang.kernel@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Since the beginning of ftrace, the code that did the patching had its
timings saved on how long it took to complete. But this information was
never exposed. It was used for debugging and exposing it was always
something that was on the TODO list. Now it's time to expose it. There's
even a file that is where it should go!
Also include how long patching modules took as a separate value.
# cat /sys/kernel/tracing/dyn_ftrace_total_info
57680 pages:231 groups: 9
ftrace boot update time = 14024666 (ns)
ftrace module total update time = 126070 (ns)
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241017113105.1edfa943@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The ftrace_lock is taken for most of the ftrace_graph_set_hash() function
throughout the end. Use guard to take the ftrace_lock to simplify the exit
paths.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071308.406073025@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The ftrace_lock is held throughout the entire release_probe() function.
Use guard to simplify any exit paths.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071308.250787901@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The ftrace_lock is held throughout cache_mod(), use guard to simplify the
error paths.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071308.088458856@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The ftrace_lock is held for most of match_records() until the end of the
function. Use guard to make error paths simpler.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071307.927146604@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
ftrace_regs was created to hold registers that store information to save
function parameters, return value and stack. Since it is a subset of
pt_regs, it should only be used by its accessor functions. But because
pt_regs can easily be taken from ftrace_regs (on most archs), it is
tempting to use it directly. But when running on other architectures, it
may fail to build or worse, build but crash the kernel!
Instead, make struct ftrace_regs an empty structure and have the
architectures define __arch_ftrace_regs and all the accessor functions
will typecast to it to get to the actual fields. This will help avoid
usage of ftrace_regs directly.
Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "x86@kernel.org" <x86@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.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: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Simplify return address printing in the function graph tracer by removing
fgraph_extras. Since this feature is only used by the function graph
tracer and the feature flags can directly accessible from the function
graph tracer, fgraph_extras can be removed from the fgraph callback.
Cc: Donglin Peng <dolinux.peng@gmail.com>
Link: https://lore.kernel.org/172857234900.270774.15378354017601069781.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When using function_graph tracer to analyze the flow of kernel function
execution, it is often necessary to quickly locate the exact line of code
where the call occurs. While this may be easy at times, it can be more
time-consuming when some functions are inlined or the flow is too long.
This feature aims to simplify the process by recording the return address
of traced funcions and printing it when outputing trace logs.
To enhance human readability, the prefix 'ret=' is used for the kernel return
value, while '<-' serves as the prefix for the return address in trace logs to
make it look more like the function tracer.
A new trace option named 'funcgraph-retaddr' has been introduced, and the
existing option 'sym-addr' can be used to control the format of the return
address.
See below logs with both funcgraph-retval and funcgraph-retaddr enabled.
0) | load_elf_binary() { /* <-bprm_execve+0x249/0x600 */
0) | load_elf_phdrs() { /* <-load_elf_binary+0x84/0x1730 */
0) | __kmalloc_noprof() { /* <-load_elf_phdrs+0x4a/0xb0 */
0) 3.657 us | __cond_resched(); /* <-__kmalloc_noprof+0x28c/0x390 ret=0x0 */
0) + 24.335 us | } /* __kmalloc_noprof ret=0xffff8882007f3000 */
0) | kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */
0) | rw_verify_area() { /* <-kernel_read+0x2b/0x50 */
0) | security_file_permission() { /* <-kernel_read+0x2b/0x50 */
0) | selinux_file_permission() { /* <-security_file_permission+0x26/0x40 */
0) | __inode_security_revalidate() { /* <-selinux_file_permission+0x6d/0x140 */
0) 2.034 us | __cond_resched(); /* <-__inode_security_revalidate+0x5f/0x80 ret=0x0 */
0) 6.602 us | } /* __inode_security_revalidate ret=0x0 */
0) 2.214 us | avc_policy_seqno(); /* <-selinux_file_permission+0x107/0x140 ret=0x0 */
0) + 16.670 us | } /* selinux_file_permission ret=0x0 */
0) + 20.809 us | } /* security_file_permission ret=0x0 */
0) + 25.217 us | } /* rw_verify_area ret=0x0 */
0) | __kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */
0) | ext4_file_read_iter() { /* <-__kernel_read+0x160/0x2e0 */
Then, we can use the faddr2line to locate the source code, for example:
$ ./scripts/faddr2line ./vmlinux load_elf_phdrs+0x6c/0xb0
load_elf_phdrs+0x6c/0xb0:
elf_read at fs/binfmt_elf.c:471
(inlined by) load_elf_phdrs at fs/binfmt_elf.c:531
Link: https://lore.kernel.org/20240915032912.1118397-1-dolinux.peng@gmail.com
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409150605.HgUmU8ea-lkp@intel.com/
Signed-off-by: Donglin Peng <dolinux.peng@gmail.com>
[ Rebased to handle text_delta offsets ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The calltime field in the shadow stack frame is only used by the function
graph tracer and profiler. But now that there's other users of the function
graph infrastructure, this adds overhead and wastes space on the shadow
stack. Move the calltime to the fgraph data storage, where the function
graph and profiler entry functions will save it in its own graph storage and
retrieve it in its exit functions.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Link: https://lore.kernel.org/20240914214827.096968730@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The fgraph "sleep-time" option tells the function graph tracer and the
profiler whether to include the time a function "sleeps" (is scheduled off
the CPU) in its duration for the function. By default it is true, which
means the duration of a function is calculated by the timestamp of when the
function was entered to the timestamp of when it exits.
If the "sleep-time" option is disabled, it needs to remove the time that the
task was not running on the CPU during the function. Currently it is done in
a sched_switch tracepoint probe where it moves the "calltime" (time of entry
of the function) forward by the sleep time calculated. It updates all the
calltime in the shadow stack.
This is time consuming for those users of the function graph tracer that
does not care about the sleep time. Instead, add a "ftrace_sleeptime" to the
task_struct that gets the sleep time added each time the task wakes up. Then
have the function entry save the current "ftrace_sleeptime" and on function
exit, move the calltime forward by the difference of the current
"ftrace_sleeptime" from the saved sleeptime.
This removes one dependency of "calltime" needed to be on the shadow stack.
It also simplifies the code that removes the sleep time of functions.
TODO: Only enable the sched_switch tracepoint when this is needed.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Link: https://lore.kernel.org/20240914214826.938908568@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Instead of having the "subtime" for the function profiler in the
infrastructure ftrace_ret_stack structure, have it use the fgraph data
reserve and retrieve functions.
This will keep the limited shadow stack from wasting 8 bytes for something
that is seldom used.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Link: https://lore.kernel.org/20240914214826.780323141@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
