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-rw-r--r--arch/x86/entry/entry_64.S117
-rw-r--r--arch/x86/entry/syscall_64.c7
2 files changed, 2 insertions, 122 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index a83570495162..c46c755f6e71 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -241,86 +241,11 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
TRACE_IRQS_OFF
- /*
- * If we need to do entry work or if we guess we'll need to do
- * exit work, go straight to the slow path.
- */
- movq PER_CPU_VAR(current_task), %r11
- testl $_TIF_WORK_SYSCALL_ENTRY|_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
- jnz entry_SYSCALL64_slow_path
-
-entry_SYSCALL_64_fastpath:
- /*
- * Easy case: enable interrupts and issue the syscall. If the syscall
- * needs pt_regs, we'll call a stub that disables interrupts again
- * and jumps to the slow path.
- */
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_NONE)
-#if __SYSCALL_MASK == ~0
- cmpq $__NR_syscall_max, %rax
-#else
- andl $__SYSCALL_MASK, %eax
- cmpl $__NR_syscall_max, %eax
-#endif
- ja 1f /* return -ENOSYS (already in pt_regs->ax) */
- movq %r10, %rcx
-
- /*
- * This call instruction is handled specially in stub_ptregs_64.
- * It might end up jumping to the slow path. If it jumps, RAX
- * and all argument registers are clobbered.
- */
-#ifdef CONFIG_RETPOLINE
- movq sys_call_table(, %rax, 8), %rax
- call __x86_indirect_thunk_rax
-#else
- call *sys_call_table(, %rax, 8)
-#endif
-.Lentry_SYSCALL_64_after_fastpath_call:
-
- movq %rax, RAX(%rsp)
-1:
-
- /*
- * If we get here, then we know that pt_regs is clean for SYSRET64.
- * If we see that no exit work is required (which we are required
- * to check with IRQs off), then we can go straight to SYSRET64.
- */
- DISABLE_INTERRUPTS(CLBR_ANY)
- TRACE_IRQS_OFF
- movq PER_CPU_VAR(current_task), %r11
- testl $_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
- jnz 1f
-
- LOCKDEP_SYS_EXIT
- TRACE_IRQS_ON /* user mode is traced as IRQs on */
- movq RIP(%rsp), %rcx
- movq EFLAGS(%rsp), %r11
- addq $6*8, %rsp /* skip extra regs -- they were preserved */
- UNWIND_HINT_EMPTY
- jmp .Lpop_c_regs_except_rcx_r11_and_sysret
-
-1:
- /*
- * The fast path looked good when we started, but something changed
- * along the way and we need to switch to the slow path. Calling
- * raise(3) will trigger this, for example. IRQs are off.
- */
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_ANY)
- SAVE_EXTRA_REGS
- movq %rsp, %rdi
- call syscall_return_slowpath /* returns with IRQs disabled */
- jmp return_from_SYSCALL_64
-
-entry_SYSCALL64_slow_path:
/* IRQs are off. */
SAVE_EXTRA_REGS
movq %rsp, %rdi
call do_syscall_64 /* returns with IRQs disabled */
-return_from_SYSCALL_64:
TRACE_IRQS_IRETQ /* we're about to change IF */
/*
@@ -393,7 +318,6 @@ syscall_return_via_sysret:
/* rcx and r11 are already restored (see code above) */
UNWIND_HINT_EMPTY
POP_EXTRA_REGS
-.Lpop_c_regs_except_rcx_r11_and_sysret:
popq %rsi /* skip r11 */
popq %r10
popq %r9
@@ -424,47 +348,6 @@ syscall_return_via_sysret:
USERGS_SYSRET64
END(entry_SYSCALL_64)
-ENTRY(stub_ptregs_64)
- /*
- * Syscalls marked as needing ptregs land here.
- * If we are on the fast path, we need to save the extra regs,
- * which we achieve by trying again on the slow path. If we are on
- * the slow path, the extra regs are already saved.
- *
- * RAX stores a pointer to the C function implementing the syscall.
- * IRQs are on.
- */
- cmpq $.Lentry_SYSCALL_64_after_fastpath_call, (%rsp)
- jne 1f
-
- /*
- * Called from fast path -- disable IRQs again, pop return address
- * and jump to slow path
- */
- DISABLE_INTERRUPTS(CLBR_ANY)
- TRACE_IRQS_OFF
- popq %rax
- UNWIND_HINT_REGS extra=0
- jmp entry_SYSCALL64_slow_path
-
-1:
- JMP_NOSPEC %rax /* Called from C */
-END(stub_ptregs_64)
-
-.macro ptregs_stub func
-ENTRY(ptregs_\func)
- UNWIND_HINT_FUNC
- leaq \func(%rip), %rax
- jmp stub_ptregs_64
-END(ptregs_\func)
-.endm
-
-/* Instantiate ptregs_stub for each ptregs-using syscall */
-#define __SYSCALL_64_QUAL_(sym)
-#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_stub sym
-#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym)
-#include <asm/syscalls_64.h>
-
/*
* %rdi: prev task
* %rsi: next task
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 9c09775e589d..c176d2fab1da 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,11 @@
#include <asm/asm-offsets.h>
#include <asm/syscall.h>
-#define __SYSCALL_64_QUAL_(sym) sym
-#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_##sym
-
-#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long __SYSCALL_64_QUAL_##qual(sym)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
#include <asm/syscalls_64.h>
#undef __SYSCALL_64
-#define __SYSCALL_64(nr, sym, qual) [nr] = __SYSCALL_64_QUAL_##qual(sym),
+#define __SYSCALL_64(nr, sym, qual) [nr] = sym,
extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);