linux.git/arch/parisc/kernel/patch.c, branch v6.0 Linux kernel source tree parisc: Fix patch code locking and flushing 2022-05-17T19:52:59+00:00 John David Anglin dave.anglin@bell.net 2022-05-16T15:32:00+00:00 798082be69fea995a475ca1db8f9873589e207d9 This change fixes the following: 1) The flags variable is not initialized. Always use raw_spin_lock_irqsave and raw_spin_unlock_irqrestore to serialize patching. 2) flush_kernel_vmap_range is primarily intended for DMA flushes. The whole cache flush in flush_kernel_vmap_range is only possible when interrupts are enabled on SMP machines. Since __patch_text_multiple calls flush_kernel_vmap_range with interrupts disabled, it is better to directly call flush_kernel_dcache_range_asm and flush_kernel_icache_range_asm. 3) The final call to flush_icache_range is unnecessary. Tested with `[PATCH, V3] parisc: Rewrite cache flush code for PA8800/PA8900' change on rp3440, c8000 and c3750 (32 and 64-bit). Note by Helge: This patch had been temporarily reverted shortly before v5.18-rc6 in order to fix boot issues. Now it can be re-applied. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> 
This change fixes the following:

1) The flags variable is not initialized. Always use raw_spin_lock_irqsave
and raw_spin_unlock_irqrestore to serialize patching.

2) flush_kernel_vmap_range is primarily intended for DMA flushes.
The whole cache flush in flush_kernel_vmap_range is only possible
when interrupts are enabled on SMP machines. Since __patch_text_multiple
calls flush_kernel_vmap_range with interrupts disabled, it is better
to directly call flush_kernel_dcache_range_asm and
flush_kernel_icache_range_asm.

3) The final call to flush_icache_range is unnecessary.

Tested with `[PATCH, V3] parisc: Rewrite cache flush code for
PA8800/PA8900' change on rp3440, c8000 and c3750 (32 and 64-bit).

Note by Helge:
This patch had been temporarily reverted shortly before v5.18-rc6 in order
to fix boot issues. Now it can be re-applied.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Revert "parisc: Fix patch code locking and flushing" 2022-05-08T18:01:11+00:00 Helge Deller deller@gmx.de 2022-05-08T08:18:40+00:00 6c800d7f55fcd78e17deae5ae4374d8e73482c13 This reverts commit a9fe7fa7d874a536e0540469f314772c054a0323. Leads to segfaults on 32bit kernel. Signed-off-by: Helge Deller <deller@gmx.de> 
This reverts commit a9fe7fa7d874a536e0540469f314772c054a0323.

Leads to segfaults on 32bit kernel.

Signed-off-by: Helge Deller <deller@gmx.de>
parisc: Fix patch code locking and flushing 2022-03-29T19:37:13+00:00 John David Anglin dave.anglin@bell.net 2022-03-29T18:54:36+00:00 a9fe7fa7d874a536e0540469f314772c054a0323 This change fixes the following: 1) The flags variable is not initialized. Always use raw_spin_lock_irqsave and raw_spin_unlock_irqrestore to serialize patching. 2) flush_kernel_vmap_range is primarily intended for DMA flushes. Since __patch_text_multiple is often called with interrupts disabled, it is better to directly call flush_kernel_dcache_range_asm and flush_kernel_icache_range_asm. This avoids an extra call. 3) The final call to flush_icache_range is unnecessary. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> 
This change fixes the following:

1) The flags variable is not initialized. Always use raw_spin_lock_irqsave
and raw_spin_unlock_irqrestore to serialize patching.

2) flush_kernel_vmap_range is primarily intended for DMA flushes. Since
__patch_text_multiple is often called with interrupts disabled, it is
better to directly call flush_kernel_dcache_range_asm and
flush_kernel_icache_range_asm. This avoids an extra call.

3) The final call to flush_icache_range is unnecessary.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
parisc: add spinlock to patch function 2019-06-08T10:56:26+00:00 Sven Schnelle svens@stackframe.org 2019-06-05T20:32:18+00:00 7e923369b1ec92af5f048d2146b44f9132abe1ad If multiple CPUs are patching code we need the spinlock to protect against parallel fixmap maps/unmap calls. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> 
If multiple CPUs are patching code we need the spinlock
to protect against parallel fixmap maps/unmap calls.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
parisc: add support for patching multiple words 2019-06-08T10:56:25+00:00 Sven Schnelle svens@stackframe.org 2019-06-05T20:32:17+00:00 4e87ace902cf0d401376cac89bb6a5239e57fe9f add patch_text_multiple() which allows to patch multiple text words in memory. This can be used to copy functions. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> 
add patch_text_multiple() which allows to patch multiple
text words in memory. This can be used to copy functions.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
parisc: remove unused flags parameter in __patch_text() 2019-05-03T21:47:39+00:00 Sven Schnelle svens@stackframe.org 2019-04-09T17:30:30+00:00 ea5a8c620ffb341b2d1a02755f9e87375523c0e5 It's not used by patch_map()/patch_unmap(), so lets remove it. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> 
It's not used by patch_map()/patch_unmap(), so lets remove
it.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
parisc: add parisc code patching 2019-05-03T21:47:38+00:00 Sven Schnelle svens@stackframe.org 2019-04-04T19:14:09+00:00 620a53d522ba007a79fffc444bd75e8d3775f5b8 Instead of re-mapping the whole kernel text with RWX rights add a patch_text() which can be used to replace instructions in the kernel .text section. Based on the ARM implementation. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> 
Instead of re-mapping the whole kernel text with RWX rights
add a patch_text() which can be used to replace instructions
in the kernel .text section. Based on the ARM implementation.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>