fgraph: Remove calltime and rettime from generic operations

The function graph infrastructure is now generic so that kretprobes,
fprobes and BPF can use it. But there is still some leftover logic th

fgraph: Remove calltime and rettime from generic operations

The function graph infrastructure is now generic so that kretprobes,
fprobes and BPF can use it. But there is still some leftover logic that
only the function graph tracer itself uses. This is the calculation of the
calltime and return time of the functions. The calculation of the calltime
has been moved into the function graph tracer and those users that need it
so that it doesn't cause overhead to the other users. But the return
function timestamp was still called.

Instead of just moving the taking of the timestamp into the function graph
trace remove the calltime and rettime completely from the ftrace_graph_ret
structure. Instead, move it into the function graph return entry event
structure and this also moves all the calltime and rettime logic out of
the generic fgraph.c code and into the tracing code that uses it.

This has been reported to decrease the overhead by ~27%.

Link: https://lore.kernel.org/all/Z3aSuql3fnXMVMoM@krava/
Link: https://lore.kernel.org/all/173665959558.1629214.16724136597211810729.stgit@devnote2/

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Link: https://lore.kernel.org/[email protected]
Reported-by: Jiri Olsa <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr

This introduces ftrace_get_symaddr() which tries to convert fentry_ip
passed by ftrace or fgraph callback to symaddr without calling
ka

ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr

This introduces ftrace_get_symaddr() which tries to convert fentry_ip
passed by ftrace or fgraph callback to symaddr without calling
kallsyms API. It returns the symbol address or 0 if it fails to
convert it.

Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/173519011487.391279.5450806886342723151.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS.
With this change, fprobe events mostly use ftrace_re

tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS.
With this change, fprobe events mostly use ftrace_regs instead of pt_regs.
Note that if the arch doesn't enable HAVE_FTRACE_REGS_HAVING_PT_REGS,
fprobe events will not be able to be used from perf.

Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/173518999352.391279.13332699755290175168.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tracing: Add ftrace_fill_perf_regs() for perf event

Add ftrace_fill_perf_regs() which should be compatible with the
perf_fetch_caller_regs(). In other words, the pt_regs returned from the
ftrace_fil

tracing: Add ftrace_fill_perf_regs() for perf event

Add ftrace_fill_perf_regs() which should be compatible with the
perf_fetch_caller_regs(). In other words, the pt_regs returned from the
ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be
used for stack tracing.

Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Will Deacon <[email protected]>
Acked-by: Heiko Carstens <[email protected]> # s390
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Naveen N Rao <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Link: https://lore.kernel.org/173518997908.391279.15910334347345106424.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs

Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs.
This is for the eBPF which needs this to keep the same p

tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs

Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs.
This is for the eBPF which needs this to keep the same pt_regs interface
to access registers.
Thus when replacing the pt_regs with ftrace_regs in fprobes (which is
used by kprobe_multi eBPF event), this will be used.

If the architecture defines its own ftrace_regs, this copies partial
registers to pt_regs and returns it. If not, ftrace_regs is the same as
pt_regs and ftrace_partial_regs() will return ftrace_regs::regs.

Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Florent Revest <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Link: https://lore.kernel.org/173518996761.391279.4987911298206448122.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

fprobe: Use ftrace_regs in fprobe exit handler

Change the fprobe exit handler to use ftrace_regs structure instead of
pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which
means the ftr

fprobe: Use ftrace_regs in fprobe exit handler

Change the fprobe exit handler to use ftrace_regs structure instead of
pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which
means the ftrace_regs is including the pt_regs so that ftrace_regs
can provide pt_regs without memory allocation.
Fprobe introduces a new dependency with that.

Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Heiko Carstens <[email protected]> # s390
Cc: Huacai Chen <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: bpf <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: KP Singh <[email protected]>
Cc: Matt Bobrowski <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Eduard Zingerman <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: Stanislav Fomichev <[email protected]>
Cc: Hao Luo <[email protected]>
Cc: Andrew Morton <[email protected]>
Link: https://lore.kernel.org/173518995092.391279.6765116450352977627.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

fgraph: Pass ftrace_regs to retfunc

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 (includ

fgraph: Pass ftrace_regs to retfunc

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 <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/173518992972.391279.14055405490327765506.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

fgraph: Replace fgraph_ret_regs with ftrace_regs

Use ftrace_regs instead of fgraph_ret_regs for tracing return value
on function_graph tracer because of simplifying the callback interface.

The CONF

fgraph: Replace fgraph_ret_regs with ftrace_regs

Use ftrace_regs instead of fgraph_ret_regs for tracing return value
on function_graph tracer because of simplifying the callback interface.

The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by
CONFIG_HAVE_FUNCTION_GRAPH_FREGS.

Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Acked-by: Will Deacon <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

fgraph: Pass ftrace_regs to entryfunc

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 (in

fgraph: Pass ftrace_regs to entryfunc

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) <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Naveen N Rao <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Link: https://lore.kernel.org/173518990044.391279.17406984900626078579.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs

Most architectures use pt_regs within ftrace_regs making a lot of the
accessor functions just calls to the pt_regs internal

ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs

Most architectures use pt_regs within ftrace_regs making a lot of the
accessor functions just calls to the pt_regs internally. Instead of
duplication this effort, use a HAVE_ARCH_FTRACE_REGS for architectures
that have their own ftrace_regs that is not based on pt_regs and will
define all the accessor functions, and for the architectures that just use
pt_regs, it will leave it undefined, and the default accessor functions
will be used.

Note, this will also make it easier to add new accessor functions to
ftrace_regs as it will mean having to touch less architectures.

Cc: <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Naveen N Rao <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Link: https://lore.kernel.org/[email protected]
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Heiko Carstens <[email protected]> # s390
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Michael Ellerman <[email protected]> # powerpc
Suggested-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

ftrace: Make ftrace_regs abstract from direct use

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_reg

ftrace: Make ftrace_regs abstract from direct use

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/[email protected]/

Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Naveen N Rao <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Link: https://lore.kernel.org/[email protected]
Acked-by: Catalin Marinas <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Heiko Carstens <[email protected]> # s390
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

fgraph: Simplify return address printing in function graph tracer

Simplify return address printing in the function graph tracer by removing
fgraph_extras. Since this feature is only used by the func

fgraph: Simplify return address printing in function graph tracer

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 <[email protected]>
Link: https://lore.kernel.org/172857234900.270774.15378354017601069781.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

function_graph: Support recording and printing the function return address

When using function_graph tracer to analyze the flow of kernel function
execution, it is often necessary to quickly locate

function_graph: Support recording and printing the function return address

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/[email protected]
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Donglin Peng <[email protected]>
[ Rebased to handle text_delta offsets ]
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

ftrace: Have calltime be saved in the fgraph storage

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 func

ftrace: Have calltime be saved in the fgraph storage

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 <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/[email protected]
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

fgraph: Use fgraph data to store subtime for profiler

Instead of having the "subtime" for the function profiler in the
infrastructure ftrace_ret_stack structure, have it use the fgraph data
reserve

fgraph: Use fgraph data to store subtime for profiler

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 <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/[email protected]
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tracing: Add a comment about ftrace_regs definition

To clarify what will be expected on ftrace_regs, add a comment to the
architecture independent definition of the ftrace_regs.

Signed-off-by: Masa

tracing: Add a comment about ftrace_regs definition

To clarify what will be expected on ftrace_regs, add a comment to the
architecture independent definition of the ftrace_regs.

Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ct

sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
virtual patch

@r1@
identifier ctl, write, buffer, lenp, ppos;
identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos);

@r2@
identifier func, ctl, write, buffer, lenp, ppos;
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos)
{ ... }

@r3@
identifier func;
@@

int func(
- struct ctl_table *
+ const struct ctl_table *
,int , void *, size_t *, loff_t *);

@r4@
identifier func, ctl;
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int , void *, size_t *, loff_t *);

@r5@
identifier func, write, buffer, lenp, ppos;
@@

int func(
- struct ctl_table *
+ const struct ctl_table *
,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
conventions. The xfs_stats_clear_proc_handler,
xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
This is called from a proc_handler itself and is calling back into
another proc_handler, making it necessary to change it as part of the
proc_handler migration.

Co-developed-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>
Co-developed-by: Joel Granados <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

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kallsyms: rework symbol lookup return codes

Building with W=1 in some configurations produces a false positive
warning for kallsyms:

kernel/kallsyms.c: In function '__sprint_symbol.isra':
kernel/ka

kallsyms: rework symbol lookup return codes

Building with W=1 in some configurations produces a false positive
warning for kallsyms:

kernel/kallsyms.c: In function '__sprint_symbol.isra':
kernel/kallsyms.c:503:17: error: 'strcpy' source argument is the same as destination [-Werror=restrict]
503 | strcpy(buffer, name);
| ^~~~~~~~~~~~~~~~~~~~

This originally showed up while building with -O3, but later started
happening in other configurations as well, depending on inlining
decisions. The underlying issue is that the local 'name' variable is
always initialized to the be the same as 'buffer' in the called functions
that fill the buffer, which gcc notices while inlining, though it could
see that the address check always skips the copy.

The calling conventions here are rather unusual, as all of the internal
lookup functions (bpf_address_lookup, ftrace_mod_address_lookup,
ftrace_func_address_lookup, module_address_lookup and
kallsyms_lookup_buildid) already use the provided buffer and either return
the address of that buffer to indicate success, or NULL for failure,
but the callers are written to also expect an arbitrary other buffer
to be returned.

Rework the calling conventions to return the length of the filled buffer
instead of its address, which is simpler and easier to follow as well
as avoiding the warning. Leave only the kallsyms_lookup() calling conventions
unchanged, since that is called from 16 different functions and
adapting this would be a much bigger change.

Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/lkml/[email protected]/
Tested-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Acked-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

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function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it

All architectures that implement function graph also implements
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR. Remove it, as it is no lon

function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it

All architectures that implement function graph also implements
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR. Remove it, as it is no longer a
differentiator.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Masami Hiramatsu <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: "Naveen N. Rao" <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

ftrace: Declare function_trace_op in header to quiet sparse warning

Sparse complains that function_trace_op is not static but is not declared
in a header file. It is used only in assembly code. But

ftrace: Declare function_trace_op in header to quiet sparse warning

Sparse complains that function_trace_op is not static but is not declared
in a header file. It is used only in assembly code. But add it to a header
so that sparse no longer complains:

kernel/trace/ftrace.c:99:19: warning: symbol 'function_trace_op' was not declared. Should it be static?

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()

Added functions that can be called by a fgraph_ops entryfunc and retfunc to
store state between the entry of the function b

function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()

Added functions that can be called by a fgraph_ops entryfunc and retfunc to
store state between the entry of the function being traced to the exit of
the same function. The fgraph_ops entryfunc() may call
fgraph_reserve_data() to store up to 32 words onto the task's shadow
ret_stack and this then can be retrieved by fgraph_retrieve_data() called
by the corresponding retfunc().

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509109089.162236.11372474169781184034.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Guo Ren <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

function_graph: Add "task variables" per task for fgraph_ops

Add a "task variables" array on the tasks shadow ret_stack that is the
size of longs for each possible registered fgraph_ops. That's a to

function_graph: Add "task variables" per task for fgraph_ops

Add a "task variables" array on the tasks shadow ret_stack that is the
size of longs for each possible registered fgraph_ops. That's a total
of 16, taking up 8 * 16 = 128 bytes (out of a page size 4k).

This will allow for fgraph_ops to do specific features on a per task basis
having a way to maintain state for each task.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509104383.162236.12239656156685718550.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Guo Ren <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

function_graph: Add pid tracing back to function graph tracer

Now that the function_graph has a main callback that handles the function
graph subops tracing, it no longer honors the pid filtering of

function_graph: Add pid tracing back to function graph tracer

Now that the function_graph has a main callback that handles the function
graph subops tracing, it no longer honors the pid filtering of ftrace. Add
back this logic in the function_graph code to update the gops callback for
the entry function to test if it should trace the current task or not.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Masami Hiramatsu <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Guo Ren <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

function_graph: Have the instances use their own ftrace_ops for filtering

Allow for instances to have their own ftrace_ops part of the fgraph_ops
that makes the funtion_graph tracer filter on the se

function_graph: Have the instances use their own ftrace_ops for filtering

Allow for instances to have their own ftrace_ops part of the fgraph_ops
that makes the funtion_graph tracer filter on the set_ftrace_filter file
of the instance and not the top instance.

This uses the new ftrace_startup_subops(), by using graph_ops as the
"manager ops" that defines the callback function and adds the functions
defined by the filters of the ops for each trace instance. The callback
defined by the manager ops will call the registered fgraph ops that were
added to the fgraph_array.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509102088.162236.15758883237657317789.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Guo Ren <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

ftrace: Allow subops filtering to be modified

The subops filters use a "manager" ops to enable and disable its filters.
The manager ops can handle more than one subops, and its filter is what
contro

ftrace: Allow subops filtering to be modified

The subops filters use a "manager" ops to enable and disable its filters.
The manager ops can handle more than one subops, and its filter is what
controls what functions get set. Add a ftrace_hash_move_and_update_subops()
function that will update the manager ops when the subops filters change.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Masami Hiramatsu <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: bpf <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Alan Maguire <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Guo Ren <[email protected]>
Reviewed-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...