Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757365Ab2JWRgJ (ORCPT ); Tue, 23 Oct 2012 13:36:09 -0400 Received: from usmamail.tilera.com ([12.216.194.151]:25554 "EHLO USMAMAIL.TILERA.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754531Ab2JWRgH (ORCPT ); Tue, 23 Oct 2012 13:36:07 -0400 Message-ID: <201210231736.q9NHa6lP014817@farm-0002.internal.tilera.com> From: Chris Metcalf Date: Tue, 23 Oct 2012 13:30:54 -0400 Subject: [PATCH] arch/tile: eliminate pt_regs trampolines for syscalls To: Al Viro CC: , , Linus Torvalds , Catalin Marinas References: <20121016223508.GR2616@ZenIV.linux.org.uk> <201210192041.q9JKf7jD003998@farm-0010.internal.tilera.com> <20121019213548.GR2616@ZenIV.linux.org.uk> <5082A1F1.3080303@tilera.com> <20121020153401.GT2616@ZenIV.linux.org.uk> <20121020171643.GU2616@ZenIV.linux.org.uk> In-Reply-To: <20121020171643.GU2616@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12564 Lines: 314 Using the new current_pt_regs() model, we can remove some trampolines from assembly code and call directly to the C syscall implementations. rt_sigreturn() and clone() still need some assembly wrapping, but no longer are passed a pt_regs pointer. sigaltstack() and the tilepro-specific cmpxchg_badaddr() syscalls are now just straight C. Signed-off-by: Chris Metcalf --- This is based on Al Viro's signal.git#arch-tile branch, which includes some ARM64 changes and some Tile changes for generic kernel execve. arch/tile/include/asm/compat.h | 9 +++------ arch/tile/include/asm/syscalls.h | 19 +++++++++++++------ arch/tile/kernel/compat.c | 4 ++-- arch/tile/kernel/compat_signal.c | 10 +++++----- arch/tile/kernel/intvec_32.S | 13 +------------ arch/tile/kernel/intvec_64.S | 13 +------------ arch/tile/kernel/process.c | 6 +++--- arch/tile/kernel/signal.c | 9 +++++---- arch/tile/kernel/sys.c | 8 +++----- arch/tile/mm/fault.c | 5 +++-- 10 files changed, 39 insertions(+), 57 deletions(-) diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h index 3bcf1b9..ca61fb4 100644 --- a/arch/tile/include/asm/compat.h +++ b/arch/tile/include/asm/compat.h @@ -280,10 +280,9 @@ long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act, size_t sigsetsize); long compat_sys_rt_sigqueueinfo(int pid, int sig, struct compat_siginfo __user *uinfo); -long compat_sys_rt_sigreturn(struct pt_regs *); +long compat_sys_rt_sigreturn(void); long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, - struct compat_sigaltstack __user *uoss_ptr, - struct pt_regs *); + struct compat_sigaltstack __user *uoss_ptr); long compat_sys_truncate64(char __user *filename, u32 dummy, u32 low, u32 high); long compat_sys_ftruncate64(unsigned int fd, u32 dummy, u32 low, u32 high); long compat_sys_pread64(unsigned int fd, char __user *ubuf, size_t count, @@ -300,9 +299,7 @@ long compat_sys_fallocate(int fd, int mode, long compat_sys_sched_rr_get_interval(compat_pid_t pid, struct compat_timespec __user *interval); -/* These are the intvec_64.S trampolines. */ -long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, - struct compat_sigaltstack __user *uoss_ptr); +/* Assembly trampoline to avoid clobbering r0. */ long _compat_sys_rt_sigreturn(void); #endif /* _ASM_TILE_COMPAT_H */ diff --git a/arch/tile/include/asm/syscalls.h b/arch/tile/include/asm/syscalls.h index 0d52992..369696d 100644 --- a/arch/tile/include/asm/syscalls.h +++ b/arch/tile/include/asm/syscalls.h @@ -51,8 +51,7 @@ long sys_cacheflush(unsigned long addr, unsigned long len, #ifndef __tilegx__ /* mm/fault.c */ -long sys_cmpxchg_badaddr(unsigned long address, struct pt_regs *); -long _sys_cmpxchg_badaddr(unsigned long address); +long sys_cmpxchg_badaddr(unsigned long address); #endif #ifdef CONFIG_COMPAT @@ -63,15 +62,23 @@ long sys_truncate64(const char __user *path, loff_t length); long sys_ftruncate64(unsigned int fd, loff_t length); #endif -/* These are the intvec*.S trampolines. */ -long _sys_sigaltstack(const stack_t __user *, stack_t __user *); -long _sys_rt_sigreturn(void); -long _sys_clone(unsigned long clone_flags, unsigned long newsp, +/* Provide versions of standard syscalls that use current_pt_regs(). */ +long sys_clone(unsigned long clone_flags, unsigned long newsp, void __user *parent_tid, void __user *child_tid); long sys_execve(const char __user *filename, const char __user *const __user *argv, const char __user *const __user *envp); +long sys_rt_sigreturn(void); +long sys_sigaltstack(const stack_t __user *, stack_t __user *); +#define sys_clone sys_clone #define sys_execve sys_execve +#define sys_rt_sigreturn sys_rt_sigreturn +#define sys_sigaltstack sys_sigaltstack + +/* These are the intvec*.S trampolines. */ +long _sys_rt_sigreturn(void); +long _sys_clone(unsigned long clone_flags, unsigned long newsp, + void __user *parent_tid, void __user *child_tid); #include diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c index a8e5a84..a2e8055 100644 --- a/arch/tile/kernel/compat.c +++ b/arch/tile/kernel/compat.c @@ -102,9 +102,9 @@ long compat_sys_sched_rr_get_interval(compat_pid_t pid, #define compat_sys_fadvise64_64 sys32_fadvise64_64 #define compat_sys_readahead sys32_readahead -/* Call the trampolines to manage pt_regs where necessary. */ -#define compat_sys_sigaltstack _compat_sys_sigaltstack +/* Call the assembly trampolines where necessary. */ #define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn +#undef sys_clone #define sys_clone _sys_clone /* diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c index 08b4fe1..210a9bb 100644 --- a/arch/tile/kernel/compat_signal.c +++ b/arch/tile/kernel/compat_signal.c @@ -197,8 +197,7 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from) } long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, - struct compat_sigaltstack __user *uoss_ptr, - struct pt_regs *regs) + struct compat_sigaltstack __user *uoss_ptr) { stack_t uss, uoss; int ret; @@ -219,7 +218,7 @@ long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, set_fs(KERNEL_DS); ret = do_sigaltstack(uss_ptr ? (stack_t __user __force *)&uss : NULL, (stack_t __user __force *)&uoss, - (unsigned long)compat_ptr(regs->sp)); + (unsigned long)compat_ptr(current_pt_regs()->sp)); set_fs(seg); if (ret >= 0 && uoss_ptr) { if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(*uoss_ptr)) || @@ -232,8 +231,9 @@ long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, } /* The assembly shim for this function arranges to ignore the return value. */ -long compat_sys_rt_sigreturn(struct pt_regs *regs) +long compat_sys_rt_sigreturn(void) { + struct pt_regs *regs = current_pt_regs(); struct compat_rt_sigframe __user *frame = (struct compat_rt_sigframe __user *) compat_ptr(regs->sp); sigset_t set; @@ -248,7 +248,7 @@ long compat_sys_rt_sigreturn(struct pt_regs *regs) if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) goto badframe; - if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0) + if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL) != 0) goto badframe; return 0; diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S index 174b837..f212bf7 100644 --- a/arch/tile/kernel/intvec_32.S +++ b/arch/tile/kernel/intvec_32.S @@ -1452,15 +1452,6 @@ STD_ENTRY_LOCAL(bad_intr) panic "Unhandled interrupt %#x: PC %#lx" STD_ENDPROC(bad_intr) -/* Put address of pt_regs in reg and jump. */ -#define PTREGS_SYSCALL(x, reg) \ - STD_ENTRY(_##x); \ - { \ - PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \ - j x \ - }; \ - STD_ENDPROC(_##x) - /* * Special-case sigreturn to not write r0 to the stack on return. * This is technically more efficient, but it also avoids difficulties @@ -1476,11 +1467,9 @@ STD_ENTRY_LOCAL(bad_intr) }; \ STD_ENDPROC(_##x) -PTREGS_SYSCALL(sys_sigaltstack, r2) PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0) -PTREGS_SYSCALL(sys_cmpxchg_badaddr, r1) -/* Save additional callee-saves to pt_regs, put address in r4 and jump. */ +/* Save additional callee-saves to pt_regs and jump to standard function. */ STD_ENTRY(_sys_clone) push_extra_callee_saves r4 j sys_clone diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 283efed..54bc9a6 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -1181,15 +1181,6 @@ STD_ENTRY_LOCAL(bad_intr) panic "Unhandled interrupt %#x: PC %#lx" STD_ENDPROC(bad_intr) -/* Put address of pt_regs in reg and jump. */ -#define PTREGS_SYSCALL(x, reg) \ - STD_ENTRY(_##x); \ - { \ - PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \ - j x \ - }; \ - STD_ENDPROC(_##x) - /* * Special-case sigreturn to not write r0 to the stack on return. * This is technically more efficient, but it also avoids difficulties @@ -1205,14 +1196,12 @@ STD_ENTRY_LOCAL(bad_intr) }; \ STD_ENDPROC(_##x) -PTREGS_SYSCALL(sys_sigaltstack, r2) PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0) #ifdef CONFIG_COMPAT -PTREGS_SYSCALL(compat_sys_sigaltstack, r2) PTREGS_SYSCALL_SIGRETURN(compat_sys_rt_sigreturn, r0) #endif -/* Save additional callee-saves to pt_regs, put address in r4 and jump. */ +/* Save additional callee-saves to pt_regs and jump to standard function. */ STD_ENTRY(_sys_clone) push_extra_callee_saves r4 j sys_clone diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index 58f8fd1..6e7fb4e 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -584,10 +584,10 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags) } /* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */ -SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, - void __user *, parent_tidptr, void __user *, child_tidptr, - struct pt_regs *, regs) +SYSCALL_DEFINE4(clone, unsigned long, clone_flags, unsigned long, newsp, + void __user *, parent_tidptr, void __user *, child_tidptr) { + struct pt_regs *regs = current_pt_regs(); if (!newsp) newsp = regs->sp; return do_fork(clone_flags, newsp, regs, 0, diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c index 67efb65..657a7ac 100644 --- a/arch/tile/kernel/signal.c +++ b/arch/tile/kernel/signal.c @@ -37,10 +37,10 @@ #define DEBUG_SIG 0 -SYSCALL_DEFINE3(sigaltstack, const stack_t __user *, uss, - stack_t __user *, uoss, struct pt_regs *, regs) +SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss, + stack_t __user *, uoss) { - return do_sigaltstack(uss, uoss, regs->sp); + return do_sigaltstack(uss, uoss, current_pt_regs()->sp); } @@ -83,8 +83,9 @@ void signal_fault(const char *type, struct pt_regs *regs, } /* The assembly shim for this function arranges to ignore the return value. */ -SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs) +SYSCALL_DEFINE0(rt_sigreturn) { + struct pt_regs *regs = current_pt_regs(); struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp); sigset_t set; diff --git a/arch/tile/kernel/sys.c b/arch/tile/kernel/sys.c index 359e76f..02ff5c0 100644 --- a/arch/tile/kernel/sys.c +++ b/arch/tile/kernel/sys.c @@ -106,13 +106,11 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, #define sys_readahead sys32_readahead #endif -/* Call the trampolines to manage pt_regs where necessary. */ -#define sys_sigaltstack _sys_sigaltstack +/* Call the assembly trampolines where necessary. */ +#undef sys_rt_sigreturn #define sys_rt_sigreturn _sys_rt_sigreturn +#undef sys_clone #define sys_clone _sys_clone -#ifndef __tilegx__ -#define sys_cmpxchg_badaddr _sys_cmpxchg_badaddr -#endif /* * Note that we can't include here since the header diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index fe811fa..3d2b81c 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -70,9 +70,10 @@ static noinline void force_sig_info_fault(const char *type, int si_signo, * Synthesize the fault a PL0 process would get by doing a word-load of * an unaligned address or a high kernel address. */ -SYSCALL_DEFINE2(cmpxchg_badaddr, unsigned long, address, - struct pt_regs *, regs) +SYSCALL_DEFINE1(cmpxchg_badaddr, unsigned long, address) { + struct pt_regs *regs = current_pt_regs(); + if (address >= PAGE_OFFSET) force_sig_info_fault("atomic segfault", SIGSEGV, SEGV_MAPERR, address, INT_DTLB_MISS, current, regs); -- 1.7.10.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/