From f8781c4a226319fe60e652118b90cf094ccfe747 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Thu, 5 Apr 2018 11:53:05 +0200 Subject: [PATCH] syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64 Removing CONFIG_SYSCALL_PTREGS from arch/x86/Kconfig and simply selecting ARCH_HAS_SYSCALL_WRAPPER unconditionally on x86-64 allows us to simplify several codepaths. Signed-off-by: Dominik Brodowski Acked-by: Linus Torvalds Cc: Al Viro Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180405095307.3730-7-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 6 +----- arch/x86/entry/common.c | 10 ++-------- arch/x86/entry/syscall_32.c | 6 +++--- arch/x86/entry/syscall_64.c | 5 ----- arch/x86/entry/vsyscall/vsyscall_64.c | 18 ------------------ arch/x86/include/asm/syscall.h | 4 ++-- arch/x86/include/asm/syscalls.h | 20 ++++---------------- 7 files changed, 12 insertions(+), 57 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7bbd6a174722..bcdd3e0e2ef5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -29,6 +29,7 @@ config X86_64 select HAVE_ARCH_SOFT_DIRTY select MODULES_USE_ELF_RELA select X86_DEV_DMA_OPS + select ARCH_HAS_SYSCALL_WRAPPER # # Arch settings @@ -2954,8 +2955,3 @@ source "crypto/Kconfig" source "arch/x86/kvm/Kconfig" source "lib/Kconfig" - -config SYSCALL_PTREGS - def_bool y - depends on X86_64 - select ARCH_HAS_SYSCALL_WRAPPER diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 425f798b39e3..fbf6a6c3fd2d 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -284,13 +284,7 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs) nr &= __SYSCALL_MASK; if (likely(nr < NR_syscalls)) { nr = array_index_nospec(nr, NR_syscalls); -#ifdef CONFIG_SYSCALL_PTREGS regs->ax = sys_call_table[nr](regs); -#else - regs->ax = sys_call_table[nr]( - regs->di, regs->si, regs->dx, - regs->r10, regs->r8, regs->r9); -#endif } syscall_return_slowpath(regs); @@ -325,7 +319,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) if (likely(nr < IA32_NR_syscalls)) { nr = array_index_nospec(nr, IA32_NR_syscalls); -#ifdef CONFIG_SYSCALL_PTREGS +#ifdef CONFIG_IA32_EMULATION regs->ax = ia32_sys_call_table[nr](regs); #else /* @@ -338,7 +332,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs) (unsigned int)regs->bx, (unsigned int)regs->cx, (unsigned int)regs->dx, (unsigned int)regs->si, (unsigned int)regs->di, (unsigned int)regs->bp); -#endif /* CONFIG_SYSCALL_PTREGS */ +#endif /* CONFIG_IA32_EMULATION */ } syscall_return_slowpath(regs); diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c index 47060dd8efb1..aa3336a7cb15 100644 --- a/arch/x86/entry/syscall_32.c +++ b/arch/x86/entry/syscall_32.c @@ -7,17 +7,17 @@ #include #include -#ifdef CONFIG_SYSCALL_PTREGS +#ifdef CONFIG_IA32_EMULATION /* On X86_64, we use struct pt_regs * to pass parameters to syscalls */ #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *); /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */ extern asmlinkage long sys_ni_syscall(const struct pt_regs *); -#else /* CONFIG_SYSCALL_PTREGS */ +#else /* CONFIG_IA32_EMULATION */ #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); -#endif /* CONFIG_SYSCALL_PTREGS */ +#endif /* CONFIG_IA32_EMULATION */ #include #undef __SYSCALL_I386 diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c index 6197850adf91..d5252bc1e380 100644 --- a/arch/x86/entry/syscall_64.c +++ b/arch/x86/entry/syscall_64.c @@ -7,14 +7,9 @@ #include #include -#ifdef CONFIG_SYSCALL_PTREGS /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */ extern asmlinkage long sys_ni_syscall(const struct pt_regs *); #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *); -#else /* CONFIG_SYSCALL_PTREGS */ -extern asmlinkage long sys_ni_syscall(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); -#endif /* CONFIG_SYSCALL_PTREGS */ #include #undef __SYSCALL_64 diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c index 05eebbf9b989..20b3d4a88ee4 100644 --- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -127,9 +127,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address) int vsyscall_nr, syscall_nr, tmp; int prev_sig_on_uaccess_err; long ret; -#ifdef CONFIG_SYSCALL_PTREGS unsigned long orig_dx; -#endif /* * No point in checking CS -- the only way to get here is a user mode @@ -230,38 +228,22 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address) ret = -EFAULT; switch (vsyscall_nr) { case 0: -#ifdef CONFIG_SYSCALL_PTREGS /* this decodes regs->di and regs->si on its own */ ret = sys_gettimeofday(regs); -#else - ret = sys_gettimeofday( - (struct timeval __user *)regs->di, - (struct timezone __user *)regs->si); -#endif /* CONFIG_SYSCALL_PTREGS */ break; case 1: -#ifdef CONFIG_SYSCALL_PTREGS /* this decodes regs->di on its own */ ret = sys_time(regs); -#else - ret = sys_time((time_t __user *)regs->di); -#endif /* CONFIG_SYSCALL_PTREGS */ break; case 2: -#ifdef CONFIG_SYSCALL_PTREGS /* while we could clobber regs->dx, we didn't in the past... */ orig_dx = regs->dx; regs->dx = 0; /* this decodes regs->di, regs->si and regs->dx on its own */ ret = sys_getcpu(regs); regs->dx = orig_dx; -#else - ret = sys_getcpu((unsigned __user *)regs->di, - (unsigned __user *)regs->si, - NULL); -#endif /* CONFIG_SYSCALL_PTREGS */ break; } diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index 17c62373a6f9..d653139857af 100644 --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -20,13 +20,13 @@ #include /* for TS_COMPAT */ #include -#ifdef CONFIG_SYSCALL_PTREGS +#ifdef CONFIG_X86_64 typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *); #else typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); -#endif /* CONFIG_SYSCALL_PTREGS */ +#endif /* CONFIG_X86_64 */ extern const sys_call_ptr_t sys_call_table[]; #if defined(CONFIG_X86_32) diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h index e4ad93c05f02..d4d18d94695c 100644 --- a/arch/x86/include/asm/syscalls.h +++ b/arch/x86/include/asm/syscalls.h @@ -19,10 +19,10 @@ /* kernel/ioport.c */ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on); -#ifndef CONFIG_SYSCALL_PTREGS -/* - * If CONFIG_SYSCALL_PTREGS is enabled, a different syscall calling convention - * is used. Do not include these -- invalid -- prototypes then +#ifdef CONFIG_X86_32 +/* + * These definitions are only valid on pure 32-bit systems; x86-64 uses a + * different syscall calling convention */ asmlinkage long sys_ioperm(unsigned long, unsigned long, int); asmlinkage long sys_iopl(unsigned int); @@ -38,7 +38,6 @@ asmlinkage long sys_set_thread_area(struct user_desc __user *); asmlinkage long sys_get_thread_area(struct user_desc __user *); /* X86_32 only */ -#ifdef CONFIG_X86_32 /* kernel/signal.c */ asmlinkage long sys_sigreturn(void); @@ -48,16 +47,5 @@ struct vm86_struct; asmlinkage long sys_vm86old(struct vm86_struct __user *); asmlinkage long sys_vm86(unsigned long, unsigned long); -#else /* CONFIG_X86_32 */ - -/* X86_64 only */ -/* kernel/process_64.c */ -asmlinkage long sys_arch_prctl(int, unsigned long); - -/* kernel/sys_x86_64.c */ -asmlinkage long sys_mmap(unsigned long, unsigned long, unsigned long, - unsigned long, unsigned long, unsigned long); - #endif /* CONFIG_X86_32 */ -#endif /* CONFIG_SYSCALL_PTREGS */ #endif /* _ASM_X86_SYSCALLS_H */