Most architectures have ftrace related stuff in arch/*/kernel/ftrace.c
but powerpc has it spread in multiple files located in
arch/powerpc/kernel/trace/
In several architectures, there are also additional files containing
'ftrace' as part of the name but with some prefix or suffix.
Use wildcards t
Murilo Opsfelder Araújo writes:
> On 3/23/22 08:51, Naveen N. Rao wrote:
...
>> +case 31:
>> +switch ((inst >> 1) & 0x3ff) {
>> +case 4: /* tw */
>> +return false;
>> +case 68:/* td */
>> +return false;
On Thu, 24 Mar 2022 11:01:45 +0100
Christophe Leroy wrote:
> @@ -1006,7 +1006,20 @@ unsigned long ftrace_graph_ret_addr(struct task_struct
> *task, int *idx,
> extern int register_ftrace_graph(struct fgraph_ops *ops);
> extern void unregister_ftrace_graph(struct fgraph_ops *ops);
>
> -extern
On Thu, 24 Mar 2022 15:38:28 +0100
Christophe Leroy wrote:
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e127c2fb08a7..3b5943f34568 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19592,6 +19592,7 @@ T:git
> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
> F:
On Thu, Mar 10, 2022 at 09:51:13AM +0100, Christophe Leroy wrote:
> Le 13/07/2021 à 02:25, Krzysztof Wilczyński a écrit :
> > The pcie_reset_state_t type has been introduced in the commit
> > f7bdd12d234d ("pci: New PCI-E reset API") along with the enum
> > pcie_reset_state, but it has never been u
Most architectures have ftrace related stuff in arch/*/kernel/ftrace.c
but powerpc has spread in multiple files located in
arch/powerpc/kernel/trace/
Signed-off-by: Christophe Leroy
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index e127c2fb08a7..
Since commit d5937db114e4 ("powerpc/code-patching: Fix patch_branch()
return on out-of-range failure") patch_branch() fails with -ERANGE
when trying to branch out of range.
No need to perform the test twice. Remove redundant create_branch()
calls.
Signed-off-by: Christophe Leroy
---
arch/powerp
Instead of returning -EPERM when patch_instruction() fails,
just return what patch_instruction returns.
That simplifies ftrace_modify_code():
0: 94 21 ff c0 stwur1,-64(r1)
4: 93 e1 00 3c stw r31,60(r1)
8: 7c 7f 1b 79 mr. r31,r3
Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target()
for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the
one for PPC64.
Same for __ftrace_make_call().
Make them common.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 108 +++
Convert last users of PPC_INST_BRANCH to PPC_RAW_BRANCH()
And remove PPC_INST_BRANCH.
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/ppc-opcode.h | 3 +--
arch/powerpc/lib/feature-fixups.c | 2 +-
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/incl
This series provides optimisation and cleanup of ftrace on powerpc.
With this series ftrace activation is about 20% faster on an 8xx.
At the end of the series come additional cleanups around ppc-opcode,
that would likely conflict with this series if posted separately.
Christophe Leroy (22):
po
Use PPC_INST_BRANCH_MASK instead of opencoding.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/module_32.c | 13 ++---
arch/powerpc/kernel/module_64.c | 4 ++--
2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/
Avoid ifdefs around expected_nop_sequence().
While at it make it a bool.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 22 ++
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/t
create_branch() is a good candidate for inlining because:
- Flags can be folded in.
- Range tests are likely to be already done.
Hence reducing the create_branch() to only a set of instructions.
So inline it.
It improves ftrace activation by 10%.
Signed-off-by: Christophe Leroy
---
arch/power
Use is_offset_in_branch_range() instead of create_branch()
to check if a target is within branch range.
This patch together with the previous one improves
ftrace activation time by 7%
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 8 ++--
1 file changed, 2 insertio
The following PPC_INST_XXX macros are not used anymore
outside ppc-opcode.h:
- PPC_INST_LD
- PPC_INST_STD
- PPC_INST_ADDIS
- PPC_INST_ADD
- PPC_INST_DIVD
Remove them.
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/ppc-opcode.h | 13 -
On the same model as get_user() versus __get_user(),
introduce __copy_inst_from_kernel_nofault() which doesn't
check address.
To be used by callers that have already checked that the adress
is a kernel address.
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/inst.h | 13 +--
To make it explicit, use BRANCH_SET_LINK instead of value 1
when calling create_branch().
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/trace/ftr
Inlining ftrace_modify_code(), it increases a bit the
size of ftrace code but brings 5% improvment on ftrace
activation.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c
When we have CONFIG_DYNAMIC_FTRACE_WITH_ARGS,
prepare_ftrace_return() is called by ftrace_graph_func()
otherwise prepare_ftrace_return() is called from assembly.
Refactor prepare_ftrace_return() into a static
__prepare_ftrace_return() that will be called by both
prepare_ftrace_return() and ftrace_
Convert last users of PPC_INST_BL to PPC_RAW_BL()
And remove PPC_INST_BL.
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/ppc-opcode.h | 1 -
arch/powerpc/net/bpf_jit.h| 2 +-
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc-opc
PPC_RAW_xxx() macros are self explanatory and less error prone
than open coding.
Use them in ftrace.c
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/ppc-opcode.h | 3 +++
arch/powerpc/kernel/trace/ftrace.c| 32 +--
2 files changed, 14 insertions(+), 21
A lot of #ifdefs can be replaced by IS_ENABLED()
Do so.
This requires to have kernel_toc_addr() defined at all time
and PPC_INST_LD_TOC as well.
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/code-patching.h | 2 -
arch/powerpc/include/asm/module.h| 2 -
arch/powerpc/
Since commit 7bea7ac0ca01 ("powerpc/syscalls: Fix syscall tracing")
ftrace.o is not needed anymore for CONFIG_FTRACE_SYSCALLS.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/Makefile | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/kernel/trace/Makefile
b/arch/powe
Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not
static"), CONFIG_DYNAMIC_FTRACE is always selected when
CONFIG_FUNCTION_TRACER is selected.
To avoid confusion and have the reader wonder what's happen when
CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not,
use
Test in is_offset_in_branch_range() and is_offset_in_cond_branch_range()
are simple tests that are worth inlining.
Signed-off-by: Christophe Leroy
---
arch/powerpc/include/asm/code-patching.h | 29 ++--
arch/powerpc/lib/code-patching.c | 27 --
2 f
ftrace_plt_tramps table is never filled so it is useless.
Remove it.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 8
1 file changed, 8 deletions(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/trace/ftrace.c
index 188f59f4ee4a..b6c
module_trampoline_target() is quite a hot path used when
activating/deactivating function tracer.
Avoid the heavy copy_from_kernel_nofault() by doing four calls
to copy_inst_from_kernel_nofault().
Use __copy_inst_from_kernel_nofault() for the 3 last calls. First call
is done to copy_from_kernel_n
0x8000 is SZ_2G. Use it.
Signed-off-by: Christophe Leroy
---
arch/powerpc/kernel/trace/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c
b/arch/powerpc/kernel/trace/ftrace.c
index afb1d12838c9..15e0746806f8 100644
--- a/arch/powe
Hi, Naveen.
Some comments below.
On 3/23/22 08:51, Naveen N. Rao wrote:
Per the ISA, a Trace interrupt is not generated for:
- [h|u]rfi[d]
- rfscv
- sc, scv, and Trap instructions that trap
- Power-Saving Mode instructions
- other instructions that cause interrupts (other than Trace interrupts)
ftrace_graph_is_dead() is used on hot paths, it just reads a variable
in memory and is not worth suffering function call constraints.
For instance, at entry of prepare_ftrace_return(), inlining it avoids
saving prepare_ftrace_return() parameters to stack and restoring them
after calling ftrace_gra
I am seeing random crashes(at least to me) with powerpc/selftests on P10 LPAR
running powerpc/merge branch code. mitigation-patching.sh test was running
in both the instances.
In the latest instance it seems like a possible stack corruption ??
[ 711.005150] count-cache-flush: hardware flush ena
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