linux-stable.git/arch/powerpc/kernel/trace, branch v5.16.2

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

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

2020-06-17T17:57:41+00:00

Better describe what these functions do.

Suggested-by: Linus Torvalds 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Linus Torvalds

powerpc: Add a probe_kernel_read_inst() function

2020-05-18T14:10:37+00:00

Introduce a probe_kernel_read_inst() function to use in cases where
probe_kernel_read() is used for getting an instruction. This will be
more useful for prefixed instructions.

Signed-off-by: Jordan Niethe 
Reviewed-by: Alistair Popple 
[mpe: Don't write to *inst on error]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200506034050.24806-15-jniethe5@gmail.com

powerpc: Use a function for reading instructions

2020-05-18T14:10:37+00:00

Prefixed instructions will mean there are instructions of different
length. As a result dereferencing a pointer to an instruction will not
necessarily give the desired result. Introduce a function for reading
instructions from memory into the instruction data type.

Signed-off-by: Jordan Niethe 
Signed-off-by: Michael Ellerman 
Reviewed-by: Alistair Popple 
Link: https://lore.kernel.org/r/20200506034050.24806-13-jniethe5@gmail.com

powerpc: Use a datatype for instructions

2020-05-18T14:10:37+00:00

Currently unsigned ints are used to represent instructions on powerpc.
This has worked well as instructions have always been 4 byte words.

However, ISA v3.1 introduces some changes to instructions that mean
this scheme will no longer work as well. This change is Prefixed
Instructions. A prefixed instruction is made up of a word prefix
followed by a word suffix to make an 8 byte double word instruction.
No matter the endianness of the system the prefix always comes first.
Prefixed instructions are only planned for powerpc64.

Introduce a ppc_inst type to represent both prefixed and word
instructions on powerpc64 while keeping it possible to exclusively
have word instructions on powerpc32.

Signed-off-by: Jordan Niethe 
[mpe: Fix compile error in emulate_spe()]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com

powerpc: Introduce functions for instruction equality

2020-05-18T14:10:37+00:00

In preparation for an instruction data type that can not be directly
used with the '==' operator use functions for checking equality.

Signed-off-by: Jordan Niethe 
Signed-off-by: Michael Ellerman 
Reviewed-by: Balamuruhan S 
Link: https://lore.kernel.org/r/20200506034050.24806-11-jniethe5@gmail.com