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authorLinus Torvalds <torvalds@linux-foundation.org>2022-04-10 06:56:46 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-10 06:56:46 -1000
commit50c94de67cfcf858d32a868dcc4e40d8581137c1 (patch)
tree26f0f5e187a11359c2d0d0c379913e4ff632b281 /arch
parent7136849ea95280685dc6a00a893501e61983b6b9 (diff)
parent273ba85b5e8b971ed28eb5c17e1638543be9237d (diff)
Merge tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Borislav Petkov: - Allow the compiler to optimize away unused percpu accesses and change the local_lock_* macros back to inline functions - A couple of fixes to static call insn patching * tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "mm/page_alloc: mark pagesets as __maybe_unused" Revert "locking/local_lock: Make the empty local_lock_*() function a macro." x86/percpu: Remove volatile from arch_raw_cpu_ptr(). static_call: Remove __DEFINE_STATIC_CALL macro static_call: Properly initialise DEFINE_STATIC_CALL_RET0() static_call: Don't make __static_call_return0 static x86,static_call: Fix __static_call_return0 for i386
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/static_call.h1
-rw-r--r--arch/x86/include/asm/percpu.h6
-rw-r--r--arch/x86/include/asm/static_call.h2
-rw-r--r--arch/x86/kernel/static_call.c5
4 files changed, 8 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/static_call.h b/arch/powerpc/include/asm/static_call.h
index 0a0bc79bd1fa..de1018cc522b 100644
--- a/arch/powerpc/include/asm/static_call.h
+++ b/arch/powerpc/include/asm/static_call.h
@@ -24,5 +24,6 @@
#define ARCH_DEFINE_STATIC_CALL_TRAMP(name, func) __PPC_SCT(name, "b " #func)
#define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) __PPC_SCT(name, "blr")
+#define ARCH_DEFINE_STATIC_CALL_RET0_TRAMP(name) __PPC_SCT(name, "b .+20")
#endif /* _ASM_POWERPC_STATIC_CALL_H */
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index a3c33b79fb86..13c0d63ed55e 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -38,9 +38,9 @@
#define arch_raw_cpu_ptr(ptr) \
({ \
unsigned long tcp_ptr__; \
- asm volatile("add " __percpu_arg(1) ", %0" \
- : "=r" (tcp_ptr__) \
- : "m" (this_cpu_off), "0" (ptr)); \
+ asm ("add " __percpu_arg(1) ", %0" \
+ : "=r" (tcp_ptr__) \
+ : "m" (this_cpu_off), "0" (ptr)); \
(typeof(*(ptr)) __kernel __force *)tcp_ptr__; \
})
#else
diff --git a/arch/x86/include/asm/static_call.h b/arch/x86/include/asm/static_call.h
index ed4f8bb6c2d9..2455d721503e 100644
--- a/arch/x86/include/asm/static_call.h
+++ b/arch/x86/include/asm/static_call.h
@@ -38,6 +38,8 @@
#define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) \
__ARCH_DEFINE_STATIC_CALL_TRAMP(name, "ret; int3; nop; nop; nop")
+#define ARCH_DEFINE_STATIC_CALL_RET0_TRAMP(name) \
+ ARCH_DEFINE_STATIC_CALL_TRAMP(name, __static_call_return0)
#define ARCH_ADD_TRAMP_KEY(name) \
asm(".pushsection .static_call_tramp_key, \"a\" \n" \
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
index 531fb4cbb63f..aa72cefdd5be 100644
--- a/arch/x86/kernel/static_call.c
+++ b/arch/x86/kernel/static_call.c
@@ -12,10 +12,9 @@ enum insn_type {
};
/*
- * data16 data16 xorq %rax, %rax - a single 5 byte instruction that clears %rax
- * The REX.W cancels the effect of any data16.
+ * cs cs cs xorl %eax, %eax - a single 5 byte instruction that clears %[er]ax
*/
-static const u8 xor5rax[] = { 0x66, 0x66, 0x48, 0x31, 0xc0 };
+static const u8 xor5rax[] = { 0x2e, 0x2e, 0x2e, 0x31, 0xc0 };
static const u8 retinsn[] = { RET_INSN_OPCODE, 0xcc, 0xcc, 0xcc, 0xcc };