linux-toradex.git/arch/powerpc/kernel/trace, branch v5.18

powerpc: Move C prototypes out of asm-prototypes.h

2022-03-08T11:06:25+00:00

We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc:
Introduce asm-prototypes.h"). It's purpose was for prototypes of C
functions that are only called from asm, in order to fix sparse
warnings about missing prototypes.

A few months later Nick added a different use case in
commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm")
for C prototypes for exported asm functions. This is basically the
inverse of our original usage.

Since then we've added various prototypes to asm-prototypes.h for both
reasons, meaning we now need to unstitch it all.

Dispatch prototypes of C functions into relevant headers and keep
only the prototypes for functions defined in assembly.

For the time being, leave prom_init() there because moving it
into asm/prom.h or asm/setup.h conflicts with
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o
This will be fixed later by untaggling asm/pci.h and asm/prom.h
or by renaming the function in shadowrom.c

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Use STK_GOT in ftrace_mprofile.S

2022-03-07T13:05:01+00:00

Instead of open coding offset value 24, use STK_GOT when
accessing got register in stack.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/9042bb30fa972056715fe5b6598a7c8049681293.1645099283.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Regroup PPC64 specific operations in ftrace_mprofile.S

2022-03-07T13:05:01+00:00

CONFIG_MPROFILE_KERNEL is only for PPC64 and ftrace_mprofile.o
is build on PPC64 only when CONFIG_MPROFILE_KERNEL is defined.

Move saving of r0 inside #ifdef PPC64

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/619dfb672bf4f1b777a4b3f8b4f14e637fea2716.1645099283.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Refactor ftrace_{regs_}caller

2022-03-07T13:05:00+00:00

ftrace_caller() and frace_regs_caller() have now a lot in common.

Refactor them using GAS macros.

Signed-off-by: Christophe Leroy 
Reviewed-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/9d7df9e4fc98a86051489f61d3c9bc67f92f7e27.1645099283.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Don't use lmw/stmw in ftrace_regs_caller()

2022-03-07T13:05:00+00:00

For the same reason as commit a85c728cb5e1 ("powerpc/32: Don't use
lmw/stmw for saving/restoring non volatile regs"), don't use
lmw/stmw in ftrace_regs_caller().

Use the same macros for PPC32 and PPC64.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/ec286d2cc6989668a96f14543275437d2f3f0e3a.1645099283.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Style cleanup in ftrace_mprofile.S

2022-02-16T12:09:47+00:00

Add some line breaks to better match the file's style, add
some space after comma and fix a couple of misplaced blanks.

Suggested-by: Naveen N. Rao 
Signed-off-by: Christophe Leroy 
Reviewed-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/973506292d0c7b05c06530c8e11803ce38e5eda2.1644949750.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Have arch_ftrace_get_regs() return NULL unless FL_SAVE_REGS is set

2022-02-16T12:09:47+00:00

When FL_SAVE_REGS is not set we get here via ftrace_caller()
which doesn't save all registers.

ftrace_caller() explicitely clears regs.msr, so we can rely
on it to know where we come from. We don't expect MSR register
to be 0 at all when involving ftrace.

Fixes: 40b035efe288 ("powerpc/ftrace: Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS")
Reported-by: Naveen N. Rao 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/2f9a7e898c93cc7438ef5ccd47cb9c3a9c5b53ef.1644949750.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Add recursion protection in prepare_ftrace_return()

2022-02-16T12:09:47+00:00

The function_graph_enter() does not provide any recursion protection.

Add a protection in prepare_ftrace_return() in case
function_graph_enter() calls something that gets
function graph traced.

Fixes: 830213786c49 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller")
Reported-by: Naveen N. Rao 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/74edf2ff0a60e66b0d9225a137100a86a0557032.1644949750.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Also save r1 in ftrace_caller()

2022-02-16T12:09:47+00:00

Also save r1 in ftrace_caller()

r1 is needed during unwinding when the function_graph tracer
is active.

Fixes: 830213786c49 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller")
Reported-by: Naveen N. Rao 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/ff535e86d3a69376a6d89168511d4e403835f18b.1644949750.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Remove ftrace_32.S

2022-02-12T11:47:28+00:00

Functions in ftrace_32.S are common with PPC64.

Reuse the ones defined for PPC64 with slight modification
when required.

Signed-off-by: Christophe Leroy 
[mpe: Squash in fixup diff from Christophe]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/5e837fc190504c4ef834272e70d60ae33f175d49.1640017960.git.christophe.leroy@csgroup.eu