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| author | Peter Zijlstra <peterz@infradead.org> | 2021-05-06 21:33:58 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-05-12 14:54:55 +0200 |
| commit | fa5e5dc39669b4427830c546ede8709323b8276c (patch) | |
| tree | 9277ff40e9c2908a6a78b8e887c0740cc5a86251 | |
| parent | f9510fa9caaf8229381d5f86ba0774bf1a6ca39b (diff) | |
| download | linux-fa5e5dc39669b4427830c546ede8709323b8276c.tar.gz linux-fa5e5dc39669b4427830c546ede8709323b8276c.tar.bz2 linux-fa5e5dc39669b4427830c546ede8709323b8276c.zip | |
jump_label, x86: Introduce jump_entry_size()
This allows architectures to have variable sized jumps.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210506194157.786777050@infradead.org
| -rw-r--r-- | arch/x86/include/asm/jump_label.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/jump_label.c | 7 | ||||
| -rw-r--r-- | include/linux/jump_label.h | 9 | ||||
| -rw-r--r-- | kernel/jump_label.c | 2 |
4 files changed, 19 insertions, 3 deletions
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index dfdc2b1c17dd..d85802a00629 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -4,8 +4,6 @@ #define HAVE_JUMP_LABEL_BATCH -#define JUMP_LABEL_NOP_SIZE 5 - #include <asm/asm.h> #include <asm/nops.h> @@ -47,6 +45,8 @@ l_yes: return true; } +extern int arch_jump_entry_size(struct jump_entry *entry); + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index 638d3b9be0ad..a29eecc14c94 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -16,6 +16,13 @@ #include <asm/alternative.h> #include <asm/text-patching.h> +#define JUMP_LABEL_NOP_SIZE JMP32_INSN_SIZE + +int arch_jump_entry_size(struct jump_entry *entry) +{ + return JMP32_INSN_SIZE; +} + static const void * __jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type) { diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 05f5554d860f..8c45f58292ac 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -176,6 +176,15 @@ static inline void jump_entry_set_init(struct jump_entry *entry) entry->key |= 2; } +static inline int jump_entry_size(struct jump_entry *entry) +{ +#ifdef JUMP_LABEL_NOP_SIZE + return JUMP_LABEL_NOP_SIZE; +#else + return arch_jump_entry_size(entry); +#endif +} + #endif #endif diff --git a/kernel/jump_label.c b/kernel/jump_label.c index ba39fbb1f8e7..521cafcfcb69 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -309,7 +309,7 @@ EXPORT_SYMBOL_GPL(jump_label_rate_limit); static int addr_conflict(struct jump_entry *entry, void *start, void *end) { if (jump_entry_code(entry) <= (unsigned long)end && - jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE > (unsigned long)start) + jump_entry_code(entry) + jump_entry_size(entry) > (unsigned long)start) return 1; return 0; |