linux-toradex.git/arch/powerpc/kernel/trace, branch v5.17

powerpc/inst: Define ppc_inst_t

2021-12-09T11:41:21+00:00

In order to stop using 'struct ppc_inst' on PPC32,
define a ppc_inst_t typedef.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/fe5baa2c66fea9db05a8b300b3e8d2880a42596c.1638208156.git.christophe.leroy@csgroup.eu

powerpc: flexible GPR range save/restore macros

2021-11-29T12:15:20+00:00

Introduce macros that operate on a (start, end) range of GPRs, which
reduces lines of code and need to do mental arithmetic while reading the
code.

Signed-off-by: Nicholas Piggin 
Reviewed-by: Segher Boessenkool 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211022061322.2671178-1-npiggin@gmail.com

powerpc/ftrace: Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32

2021-11-29T11:49:29+00:00

Unlike PPC64, PPC32 doesn't require any special compiler option
to get _mcount() call not clobbering registers.

Provide ftrace_regs_caller() and ftrace_regs_call() and activate
HAVE_DYNAMIC_FTRACE_WITH_REGS.

That's heavily copied from ftrace_64_mprofile.S

For the time being leave livepatching aside, it will come with
following patch.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/1862dc7719855cc2a4eec80920d94c955877557e.1635423081.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Add module_trampoline_target() for PPC32

2021-11-29T11:49:29+00:00

module_trampoline_target() is used by __ftrace_modify_call().

Implement it for PPC32 so that CONFIG_DYNAMIC_FTRACE_WITH_REGS
can be activated on PPC32 as well.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/42345f464fb465f0fc76f3090e250be8fc1729f0.1635423081.git.christophe.leroy@csgroup.eu

powerpc/ftrace: No need to read LR from stack in _mcount()

2021-11-29T11:49:29+00:00

All functions calling _mcount do it exactly the same way, with the
following sequence of instructions:

	c07de788:       7c 08 02 a6     mflr    r0
	c07de78c:       90 01 00 04     stw     r0,4(r1)
	c07de790:       4b 84 13 65     bl      c001faf4 <_mcount>

Allthough LR is pushed on stack, it is still in r0 while entering
_mcount().

Function arguments are in r3-r10, so r11 and r12 are still available
at that point.

Do like PPC64 and use r12 to move LR into CTR, so that r0 is preserved
and doesn't need to be restored from the stack.

While at it, bring back the EXPORT_SYMBOL at the end of _mcount.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/24a3ba7db388537c44a038026f926d885372e6d3.1635423081.git.christophe.leroy@csgroup.eu

powerpc: Don't use 'struct ppc_inst' to reference instruction location

2021-06-16T14:09:00+00:00

'struct ppc_inst' is an internal representation of an instruction, but
in-memory instructions are and will remain a table of 'u32' forever.

Replace all 'struct ppc_inst *' used for locating an instruction in
memory by 'u32 *'. This removes a lot of undue casts to 'struct
ppc_inst *'.

It also helps locating ab-use of 'struct ppc_inst' dereference.

Signed-off-by: Christophe Leroy 
[mpe: Fix ppc_inst_next(), use u32 instead of unsigned int]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Use PPC_RAW_MFLR() and PPC_RAW_NOP()

2021-06-15T14:16:48+00:00

Use PPC_RAW_MFLR() instead of open coding with PPC_INST_MFLR.

Same for PPC_INST_NOP.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/98fd4d717810b7c4032a1edf62dd6fe638e64329.1621506159.git.christophe.leroy@csgroup.eu

powerpc/lib/code-patching: Use PPC_RAW_() macros

2021-06-15T14:16:47+00:00

Instead of open coding with PPC_INST_ defines, use
PPC_RAW_() macros. It improves readability.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/8c92f1d9e825ee47c6f88fe43ad42d2a8cc2ab4a.1621506159.git.christophe.leroy@csgroup.eu

powerpc: Rename probe_kernel_read_inst()

2021-04-21T12:52:33+00:00

When probe_kernel_read_inst() was created, it was to mimic
probe_kernel_read() function.

Since then, probe_kernel_read() has been renamed
copy_from_kernel_nofault().

Rename probe_kernel_read_inst() into copy_inst_from_kernel_nofault().

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/b783d1f7cdb8914992384a669a2af57051b6bdcf.1618405715.git.christophe.leroy@csgroup.eu

powerpc: Add a ppc_inst_as_str() helper

2020-07-23T07:41:36+00:00

There are quite a few places where instructions are printed, this is
done using a '%x' format specifier. With the introduction of prefixed
instructions, this does not work well. Currently in these places,
ppc_inst_val() is used for the value for %x so only the first word of
prefixed instructions are printed.

When the instructions are word instructions, only a single word should
be printed. For prefixed instructions both the prefix and suffix should
be printed. To accommodate both of these situations, instead of a '%x'
specifier use '%s' and introduce a helper, __ppc_inst_as_str() which
returns a char *. The char * __ppc_inst_as_str() returns is buffer that
is passed to it by the caller.

It is cumbersome to require every caller of __ppc_inst_as_str() to now
declare a buffer. To make it more convenient to use __ppc_inst_as_str(),
wrap it in a macro that uses a compound statement to allocate a buffer
on the caller's stack before calling it.

Signed-off-by: Jordan Niethe 
Reviewed-by: Joel Stanley 
Acked-by: Segher Boessenkool 
[mpe: Drop 0x prefix to match most existings uses, especially xmon]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200602052728.18227-1-jniethe5@gmail.com