This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.
As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Pull probes updates from Masami Hiramatsu:
"fprobe performance enhancement using rhltable:
- use rhltable for fprobe_ip_table. The fprobe IP table has been
converted to use an rhltable for improved performance when dealing
with a large number of probed functions
- Fix a suspicious RCU usage warning of the above change in the
fprobe entry handler
- Remove an unused local variable of the above change
- Fix to initialize fprobe_ip_table in core_initcall()
Performance optimization of fprobe by ftrace:
- Use ftrace instead of fgraph for entry only probes. This avoids the
unneeded overhead of fgraph stack setup
- Also update fprobe selftest for entry-only probe
- fprobe: Use ftrace only if CONFIG_DYNAMIC_FTRACE_WITH_ARGS or
WITH_REGS is defined
Cleanup probe event subsystems:
- Allocate traceprobe_parse_context per probe instead of each probe
argument parsing. This reduce memory allocation/free of temporary
working memory
- Cleanup code using __free()
- Replace strcpy() with memcpy() in __trace_probe_log_err()"
* tag 'probes-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: fprobe: use ftrace if CONFIG_DYNAMIC_FTRACE_WITH_ARGS
lib/test_fprobe: add testcase for mixed fprobe
tracing: fprobe: optimization for entry only case
tracing: fprobe: Fix to init fprobe_ip_table earlier
tracing: fprobe: Remove unused local variable
tracing: probes: Replace strcpy() with memcpy() in __trace_probe_log_err()
tracing: fprobe: fix suspicious rcu usage in fprobe_entry
tracing: uprobe: eprobes: Allocate traceprobe_parse_context per probe
tracing: uprobes: Cleanup __trace_uprobe_create() with __free()
tracing: eprobe: Cleanup eprobe event using __free()
tracing: probes: Use __free() for trace_probe_log
tracing: fprobe: use rhltable for fprobe_ip_table
Now that there's pretty much a one to one mapping between the struct
event_trigger_ops and struct event_command, there's no reason to have two
different structures. Merge the function pointers of event_trigger_ops
into event_command.
There's one exception in trace_events_hist.c for the
event_hist_trigger_named_ops. This has special logic for the init and free
function pointers for "named histograms". In this case, allocate the
cmd_ops of the event_trigger_data and set it to the proper init and free
functions, which are used to initialize and free the event_trigger_data
respectively. Have the free function and the init function (on failure)
free the cmd_ops of the data element.
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://patch.msgid.link/20251125200932.446322765@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The struct event_command has a callback function called get_trigger_ops().
This callback returns the "trigger_ops" to use for the trigger. These ops
define the trigger function, how to init the trigger, how to print the
trigger and how to free it.
The only reason there's a callback function to get these ops is because
some triggers have two types of operations. One is an "always on"
operation, and the other is a "count down" operation. If a user passes in
a parameter to say how many times the trigger should execute. For example:
echo stacktrace:5 > events/kmem/kmem_cache_alloc/trigger
It will trigger the stacktrace for the first 5 times the kmem_cache_alloc
event is hit.
Instead of having two different trigger_ops since the only difference
between them is the tigger itself (the print, init and free functions are
all the same), just use a single ops that the event_command points to and
add a function field to the trigger_ops to have a count_func.
When a trigger is added to an event, if there's a count attached to it and
the trigger ops has the count_func field, the data allocated to represent
this trigger will have a new flag set called COUNT.
Then when the trigger executes, it will check if the COUNT data flag is
set, and if so, it will call the ops count_func(). If that returns false,
it returns without executing the trigger.
This removes the need for duplicate event_trigger_ops structures.
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://patch.msgid.link/20251125200932.274566147@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
eprobes are dynamic events that can read other events using their fields
to create new events. Currently it doesn't work with arrays. When the new
event field is attached to the old event field, it looks at the size of
the field to determine what type of field the new field should be. For 1
byte fields it's a char, for 2 bytes, it's a short and for 4 bytes it's an
integer. For all other sizes it just defaults to "long". This also reads
the contents of the field for such cases.
For arrays that are bigger than the size of long, return the value of the
address of the content itself. This will allow eprobes to read other
values in the array of the old event.
This is useful when raw_syscalls is enabled but the syscall events are
not. The syscall events are created from the raw_syscalls as they have an
array of "args" that holds the 6 long words passed to the syscall entry
point. To read the value of "filename" from sys_openat, the eprobe could
attach to the raw_syscall and read the second value.
It can then even be passed to a synthetic event and converted back to
another eprobe to get the value of "filename" after it has been read by
the kernel during the system call:
[
Create an eprobe called "sys" and attach it to sys_enter.
Read the id of the system call and the second argument
]
# echo 'e:sys raw_syscalls.sys_enter nr=$id:u32 arg2=+8($args):u64' >> /sys/kernel/tracing/dynamic_events
[
Create a synthetic event "path" that will hold the address of the
sys_openat filename. This is on a 64bit machine, so make it 64 bits
]
# echo 's:path u64 file;' >> /sys/kernel/tracing/dynamic_events
[
Add a histogram to the eprobe/sys which tiggers if the "nr" field is
257 (sys_openat), and save the filename in the "file" variable.
]
# echo 'hist:keys=common_pid:file=arg2 if nr == 257' > /sys/kernel/tracing/events/eprobes/sys/trigger
[
Attach a histogram to sys_exit event that triggers the "path" synthetic
event and records the "filename" that was passed from the sys eprobe.
]
# echo 'hist:keys=common_pid:f=$file:onmatch(eprobes.sys).trace(path,$f)' >> /sys/kernel/tracing/events/raw_syscalls/sys_exit/trigger
[
Create another eprobe that dereferences the "file" field as a user
space string and displays it.
]
# echo 'e:open synthetic.path file=+0($file):ustring' >> /sys/kernel/tracing/dynamic_events
# echo 1 > /sys/kernel/tracing/events/eprobes/open/enable
# cat trace_pipe
cat-1142 [003] ...5. 799.521912: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.521934: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522065: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522080: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522296: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
cat-1142 [003] ...5. 799.522319: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522327: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522333: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
cat-1142 [003] ...5. 799.522348: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522349: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522363: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522477: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522489: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522492: open: (synthetic.path) file="/etc/ld.so.cache"
less-1143 [005] ...5. 799.522720: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libtinfo.so.6"
less-1143 [005] ...5. 799.522744: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libtinfo.so.6"
less-1143 [005] ...5. 799.522759: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libtinfo.so.6"
cat-1142 [003] ...5. 799.522850: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
Link: https://lore.kernel.org/all/20250723124202.4f7475be@batman.local.home/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Pull probes updates from Masami Hiramatsu:
- probe-events: Add comments about entry data storing code to clarify
where and how the entry data is stored for function return events.
- probe-events: Log error for exceeding the number of arguments to help
user to identify error reason via tracefs/error_log file.
- Improve the ftracetest selftests:
- Expand the tprobe event test to check if it can correctly find the
wrong format tracepoint name.
- Add new syntax error test to check whether error_log correctly
indicates a wrong character in the tracepoint name.
- Add a new dynamic events argument limitation test case which
checks max number of probe arguments.
* tag 'probes-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: probe-events: Add comments about entry data storing code
selftests/ftrace: Add dynamic events argument limitation test case
selftests/ftrace: Add new syntax error test
selftests/ftrace: Expand the tprobe event test to check wrong format
tracing: probe-events: Log error for exceeding the number of arguments
'event_trigger_ops mwifiex_if_ops' are not modified in these drivers.
Constifying these structures moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.
On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
31368 9024 6200 46592 b600 kernel/trace/trace_events_trigger.o
After:
=====
text data bss dec hex filename
31752 8608 6200 46560 b5e0 kernel/trace/trace_events_trigger.o
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/66e8f990e649678e4be37d4d1a19158ca0dea2f4.1741521295.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When creating a trace_probe we would set nr_args prior to truncating the
arguments to MAX_TRACE_ARGS. However, we would only initialize arguments
up to the limit.
This caused invalid memory access when attempting to set up probes with
more than 128 fetchargs.
BUG: kernel NULL pointer dereference, address: 0000000000000020
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
RIP: 0010:__set_print_fmt+0x134/0x330
Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return
an error when there are too many arguments instead of silently
truncating.
Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/
Fixes: 035ba76014 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init")
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Support accessing $argN in the return probe events. This will help users to
record entry data in function return (exit) event for simplfing the function
entry/exit information in one event, and record the result values (e.g.
allocated object/initialized object) at function exit.
For example, if we have a function `int init_foo(struct foo *obj, int param)`
sometimes we want to check how `obj` is initialized. In such case, we can
define a new return event like below;
# echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events
Thus it records the function parameter `param` and its result `obj->field1`
(the dereference will be done in the function exit timing) value at once.
This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF
is enabled, we can trace both function parameters and the return value
by following command.
# echo 'f target_function%return $arg* $retval' >> dynamic_events
Link: https://lore.kernel.org/all/170952365552.229804.224112990211602895.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since the btf returned from bpf_get_btf_vmlinux() only covers functions in
the vmlinux, BTF argument is not available on the functions in the modules.
Use bpf_find_btf_id() instead of bpf_get_btf_vmlinux()+btf_find_name_kind()
so that BTF argument can find the correct struct btf and btf_type in it.
With this fix, fprobe events can use `$arg*` on module functions as below
# grep nf_log_ip_packet /proc/kallsyms
ffffffffa0005c00 t nf_log_ip_packet [nf_log_syslog]
ffffffffa0005bf0 t __pfx_nf_log_ip_packet [nf_log_syslog]
# echo 'f nf_log_ip_packet $arg*' > dynamic_events
# cat dynamic_events
f:fprobes/nf_log_ip_packet__entry nf_log_ip_packet net=net pf=pf hooknum=hooknum skb=skb in=in out=out loginfo=loginfo prefix=prefix
To support the module's btf which is removable, the struct btf needs to be
ref-counted. So this also records the btf in the traceprobe_parse_context
and returns the refcount when the parse has done.
Link: https://lore.kernel.org/all/169272154223.160970.3507930084247934031.stgit@devnote2/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
