linux-toradex.git/arch/powerpc/lib/code-patching.c, branch v5.17

powerpc/code-patching: Move code patching selftests in its own file

2021-12-23T11:36:58+00:00

Code patching selftests are half of code-patching.c.
As they are guarded by CONFIG_CODE_PATCHING_SELFTESTS,
they'd be better in their own file.

Also add a missing __init for instr_is_branch_to_addr()

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/c0c30504f04eb546a48ff77127a8bccd12a3d809.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Move instr_is_branch_{i/b}form() in code-patching.h

2021-12-23T11:36:58+00:00

To enable moving selftests in their own C file in following patch,
move instr_is_branch_iform() and instr_is_branch_bform()
to code-patching.h

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/fca0f3b191211b3681020885a611bf73eef20563.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Move patch_exception() outside code-patching.c

2021-12-23T11:36:55+00:00

patch_exception() is dedicated to book3e/64 is nothing more than
a normal use of patch_branch(), so move it into a place dedicated
to book3e/64.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/0968622b98b1fb51838c35b844c42ad6609de62e.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Use test_trampoline for prefixed patch test

2021-12-23T11:35:25+00:00

Use the dedicated test_trampoline function for testing prefixed
patching like other tests and remove the hand coded assembly stuff.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a450ef3f8653f75e1bd9aaf7a3889d379752f33b.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Fix patch_branch() return on out-of-range failure

2021-12-23T11:35:24+00:00

Do not silentely ignore a failure of create_branch() in
patch_branch(). Return -ERANGE.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/8540cb64b1f06710eaf41e3835c7ba3e21fa2b05.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Reorganise do_patch_instruction() to ease error handling

2021-12-23T11:35:24+00:00

Split do_patch_instruction() in two functions, the caller doing the
spin locking and the callee doing everything else.

And remove a few unnecessary initialisations and intermediate
variables.

This allows the callee to return from anywhere in the function.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/dbc85980a0d2a935731b272e8907e8bb1d8fc8c5.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Fix unmap_patch_area() error handling

2021-12-23T11:35:24+00:00

pXd_offset() doesn't return NULL. When the base is NULL, it
still adds the offset.

Use pXd_none() to check validity instead. It also improves
performance by folding out none existing levels as pXd_none()
always returns 0 in that case.

Such an error is unexpected, use WARN_ON() so that the caller
doesn't have to worry about it, and drop the returned value.

And now that unmap_patch_area() doesn't return error, we can
take into account the error returned by __patch_instruction().

While at it, remove the 'inline' property which is useless.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/299804b117fae35c786c827536c91f25352e279b.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Fix error handling in do_patch_instruction()

2021-12-23T11:35:24+00:00

Use real errors instead of using -1 as error, so that errors
returned by callees can be used towards callers.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/85259d894069e47f915ea580b169e1adbeec7a61.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Remove init_mem_is_free

2021-12-23T11:35:24+00:00

A new state has been added by commit d2635f2012a4 ("mm: create a new
system state and fix core_kernel_text()"). That state tells when
initmem is about to be released and is redundant with init_mem_is_free.

Remove init_mem_is_free.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/ad8c3ccb39c8edaa89fd3eda1cc7218baea1cde5.1638446239.git.christophe.leroy@csgroup.eu

powerpc/code-patching: Remove pr_debug()/pr_devel() messages and fix check()

2021-12-23T11:35:24+00:00

code-patching has been working for years now, time has come to
remove debugging messages.

Change useful message to KERN_INFO and remove other ones.

Also add KERN_ERR to check() macro and change it into a do/while
to make checkpatch happy.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/3ff9823c0a812a8a145d979a9600a6d4591b80ee.1638446239.git.christophe.leroy@csgroup.eu