Messages in this thread | | | From | Ard Biesheuvel <> | Subject | [PATCH 0/3] jump_label: get rid of NOP patching where possible | Date | Wed, 8 Jun 2022 12:45:09 +0200 |
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The only architecture that actually needs to convert compiler generated jump label NOP encodings into something else at runtime is MIPS, because the assembler cannot be trusted to emit a sequence that can be safely patched into a branch instruction.
All other architectures either do nothing with jump label NOPs at load time, or patch a perfectly good NOP into a different one, or into the same one - none of this seems very useful, so let's get rid of it where we can.
Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: linux-mips@vger.kernel.org Cc: linux-s390@vger.kernel.org
Ard Biesheuvel (3): jump_label: s390: avoid pointless initial NOP patching jump_label: mips: move module NOP patching into arch code jump_label: make initial NOP patching the special case
Documentation/staging/static-keys.rst | 3 -- arch/arc/kernel/jump_label.c | 13 ------- arch/arm/kernel/jump_label.c | 6 --- arch/arm64/kernel/jump_label.c | 11 ------ arch/mips/include/asm/jump_label.h | 2 + arch/mips/kernel/jump_label.c | 17 ++++++++ arch/mips/kernel/module.c | 5 ++- arch/parisc/kernel/jump_label.c | 11 ------ arch/riscv/kernel/jump_label.c | 12 ------ arch/s390/include/asm/jump_label.h | 5 +-- arch/s390/kernel/jump_label.c | 28 +++---------- arch/s390/kernel/module.c | 1 - arch/sparc/kernel/module.c | 3 -- arch/x86/kernel/jump_label.c | 13 ------- arch/x86/kernel/module.c | 3 -- include/linux/jump_label.h | 7 +--- kernel/jump_label.c | 41 ++------------------ 17 files changed, 34 insertions(+), 147 deletions(-)
-- 2.30.2
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