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-rw-r--r--arch/x86/include/asm/static_call.h15
-rw-r--r--arch/x86/include/asm/sync_core.h6
-rw-r--r--arch/x86/kernel/static_call.c9
-rw-r--r--include/linux/compiler.h37
-rw-r--r--include/linux/static_call.h1
-rw-r--r--kernel/static_call_inline.c2
6 files changed, 55 insertions, 15 deletions
diff --git a/arch/x86/include/asm/static_call.h b/arch/x86/include/asm/static_call.h
index 125c407e2abe..41502bd2afd6 100644
--- a/arch/x86/include/asm/static_call.h
+++ b/arch/x86/include/asm/static_call.h
@@ -65,4 +65,19 @@
extern bool __static_call_fixup(void *tramp, u8 op, void *dest);
+extern void __static_call_update_early(void *tramp, void *func);
+
+#define static_call_update_early(name, _func) \
+({ \
+ typeof(&STATIC_CALL_TRAMP(name)) __F = (_func); \
+ if (static_call_initialized) { \
+ __static_call_update(&STATIC_CALL_KEY(name), \
+ STATIC_CALL_TRAMP_ADDR(name), __F);\
+ } else { \
+ WRITE_ONCE(STATIC_CALL_KEY(name).func, _func); \
+ __static_call_update_early(STATIC_CALL_TRAMP_ADDR(name),\
+ __F); \
+ } \
+})
+
#endif /* _ASM_STATIC_CALL_H */
diff --git a/arch/x86/include/asm/sync_core.h b/arch/x86/include/asm/sync_core.h
index ab7382f92aff..96bda43538ee 100644
--- a/arch/x86/include/asm/sync_core.h
+++ b/arch/x86/include/asm/sync_core.h
@@ -8,7 +8,7 @@
#include <asm/special_insns.h>
#ifdef CONFIG_X86_32
-static inline void iret_to_self(void)
+static __always_inline void iret_to_self(void)
{
asm volatile (
"pushfl\n\t"
@@ -19,7 +19,7 @@ static inline void iret_to_self(void)
: ASM_CALL_CONSTRAINT : : "memory");
}
#else
-static inline void iret_to_self(void)
+static __always_inline void iret_to_self(void)
{
unsigned int tmp;
@@ -55,7 +55,7 @@ static inline void iret_to_self(void)
* Like all of Linux's memory ordering operations, this is a
* compiler barrier as well.
*/
-static inline void sync_core(void)
+static __always_inline void sync_core(void)
{
/*
* The SERIALIZE instruction is the most straightforward way to
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
index 4eefaac64c6c..9eed0c144dad 100644
--- a/arch/x86/kernel/static_call.c
+++ b/arch/x86/kernel/static_call.c
@@ -172,6 +172,15 @@ void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
}
EXPORT_SYMBOL_GPL(arch_static_call_transform);
+noinstr void __static_call_update_early(void *tramp, void *func)
+{
+ BUG_ON(system_state != SYSTEM_BOOTING);
+ BUG_ON(!early_boot_irqs_disabled);
+ BUG_ON(static_call_initialized);
+ __text_gen_insn(tramp, JMP32_INSN_OPCODE, tramp, func, JMP32_INSN_SIZE);
+ sync_core();
+}
+
#ifdef CONFIG_MITIGATION_RETHUNK
/*
* This is called by apply_returns() to fix up static call trampolines,
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 4d4e23b6e3e7..2d962dade9fa 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -216,28 +216,43 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
#endif /* __KERNEL__ */
+/**
+ * offset_to_ptr - convert a relative memory offset to an absolute pointer
+ * @off: the address of the 32-bit offset value
+ */
+static inline void *offset_to_ptr(const int *off)
+{
+ return (void *)((unsigned long)off + *off);
+}
+
+#endif /* __ASSEMBLY__ */
+
+#ifdef CONFIG_64BIT
+#define ARCH_SEL(a,b) a
+#else
+#define ARCH_SEL(a,b) b
+#endif
+
/*
* Force the compiler to emit 'sym' as a symbol, so that we can reference
* it from inline assembler. Necessary in case 'sym' could be inlined
* otherwise, or eliminated entirely due to lack of references that are
* visible to the compiler.
*/
-#define ___ADDRESSABLE(sym, __attrs) \
- static void * __used __attrs \
+#define ___ADDRESSABLE(sym, __attrs) \
+ static void * __used __attrs \
__UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)(uintptr_t)&sym;
+
#define __ADDRESSABLE(sym) \
___ADDRESSABLE(sym, __section(".discard.addressable"))
-/**
- * offset_to_ptr - convert a relative memory offset to an absolute pointer
- * @off: the address of the 32-bit offset value
- */
-static inline void *offset_to_ptr(const int *off)
-{
- return (void *)((unsigned long)off + *off);
-}
+#define __ADDRESSABLE_ASM(sym) \
+ .pushsection .discard.addressable,"aw"; \
+ .align ARCH_SEL(8,4); \
+ ARCH_SEL(.quad, .long) __stringify(sym); \
+ .popsection;
-#endif /* __ASSEMBLY__ */
+#define __ADDRESSABLE_ASM_STR(sym) __stringify(__ADDRESSABLE_ASM(sym))
/* &a[0] degrades to a pointer: a different type from an array */
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
diff --git a/include/linux/static_call.h b/include/linux/static_call.h
index 141e6b176a1b..785980af8972 100644
--- a/include/linux/static_call.h
+++ b/include/linux/static_call.h
@@ -138,6 +138,7 @@
#ifdef CONFIG_HAVE_STATIC_CALL
#include <asm/static_call.h>
+extern int static_call_initialized;
/*
* Either @site or @tramp can be NULL.
*/
diff --git a/kernel/static_call_inline.c b/kernel/static_call_inline.c
index 5259cda486d0..bb7d066a7c39 100644
--- a/kernel/static_call_inline.c
+++ b/kernel/static_call_inline.c
@@ -15,7 +15,7 @@ extern struct static_call_site __start_static_call_sites[],
extern struct static_call_tramp_key __start_static_call_tramp_key[],
__stop_static_call_tramp_key[];
-static int static_call_initialized;
+int static_call_initialized;
/*
* Must be called before early_initcall() to be effective.