Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756479Ab2JTRQt (ORCPT ); Sat, 20 Oct 2012 13:16:49 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:39023 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756325Ab2JTRQq (ORCPT ); Sat, 20 Oct 2012 13:16:46 -0400 Date: Sat, 20 Oct 2012 18:16:43 +0100 From: Al Viro To: Chris Metcalf Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Linus Torvalds , Catalin Marinas Subject: Re: [PATCH] tile: support GENERIC_KERNEL_THREAD and GENERIC_KERNEL_EXECVE Message-ID: <20121020171643.GU2616@ZenIV.linux.org.uk> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121020153401.GT2616@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7619 Lines: 161 On Sat, Oct 20, 2012 at 04:34:01PM +0100, Al Viro wrote: > On Sat, Oct 20, 2012 at 09:06:57AM -0400, Chris Metcalf wrote: > > First, the compat_sys_execve() declaration provided in > > arch/tile/include/asm/compat.h isn't right, so I deleted that (you had only > > deleted the PTREGS_SYSCALL trampoline declaration, _compat_sys_execve). > > > > However, then arch/tile/kernel/compat.c failed to build, because > > is included before , and > > provides __ARCH_WANT_SYS_EXECVE, and so we end up with no declaration at > > all for compat_sys_execve. For most platforms this is no big deal, but on > > tile we use the __SYSCALL #define to provide the actual syscall table, and > > for that to work we need a declaration in scope for each syscall at the > > time we create the table. > > > > The best solution seems likely to be to copy the other place in > > where we need to do something configurable (that is, > > CONFIG_ARCH_WANT_OLD_COMPAT_IPC), and just convert __ARCH_WANT_SYS_EXECVE > > to be a Kconfig option. > > Frankly, I hope to get rid of the damn thing completely. By now we have > at least some variant of execve conversions for just about everything; > I certainly hope that by the beginning of the next cycle we'll have it > defined on everything. And put unconditional declarations in syscalls.h > and compat.h > > Actually, we can make the declaration in linux/compat.h unconditional > right now. The only obstacle is the situation on arm64; there the mainline > has C variant of that sucker (with struct pt_regs * in arguments) in > arch/arm64/kernel/sys_compat.c. So we could ask Linus to pull > git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64 execve > and then do the following in one patch: > introduce current_pt_regs() on tile (from your commit) > get rid of pt_regs * argument in tile compat_sys_execve(), making it > use current_pt_regs(); kill its wrapper > kill the declarations of compat_sys_execve()/_compat_sys_execve() > in tile asm/compat.h > make declaration in linux/compat.h unconditional > Note that this does *not* depend on kernel_thread/kernel_execve patch - > kernel_execve() is never going to hit compat_sys_execve(), since it's > only called from kernel threads and those are not going to be 32bit. > After that we can do kernel_thread/kernel_execve commit and > sys_execve() conversion with nothing outside of arch/tile touched. Another possible variant is for you to merge that branch from arm64 tree (only 3 commits it it) and then do as described above. I.e. on top of that apply the thing below, followed by your kernel_thread()/kernel_execve() patch (sans current_pt_regs() part), followed by obviously massaged parts of generic sys_execve for tile patch I've sent. FWIW, I've put the whole series (based at the end of arm64 branch) in signal.git#arch-tile. Comments? Drop struct pt_regs * argument in compat_sys_execve() Signed-off-by: Al Viro --- diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h index 3063e6f..3bcf1b9 100644 --- a/arch/tile/include/asm/compat.h +++ b/arch/tile/include/asm/compat.h @@ -275,9 +275,6 @@ extern int compat_setup_rt_frame(int sig, struct k_sigaction *ka, struct compat_sigaction; struct compat_siginfo; struct compat_sigaltstack; -long compat_sys_execve(const char __user *path, - compat_uptr_t __user *argv, - compat_uptr_t __user *envp, struct pt_regs *); long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act, struct compat_sigaction __user *oact, size_t sigsetsize); @@ -304,9 +301,6 @@ 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_execve(const char __user *path, - const compat_uptr_t __user *argv, - const compat_uptr_t __user *envp); long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, struct compat_sigaltstack __user *uoss_ptr); long _compat_sys_rt_sigreturn(void); diff --git a/arch/tile/include/asm/processor.h b/arch/tile/include/asm/processor.h index 8c4dd9f..9a83e53 100644 --- a/arch/tile/include/asm/processor.h +++ b/arch/tile/include/asm/processor.h @@ -239,6 +239,9 @@ unsigned long get_wchan(struct task_struct *p); #define KSTK_TOP(task) (task_ksp0(task) - STACK_TOP_DELTA) #define task_pt_regs(task) \ ((struct pt_regs *)(task_ksp0(task) - KSTK_PTREGS_GAP) - 1) +#define current_pt_regs() \ + ((struct pt_regs *)((stack_pointer | (THREAD_SIZE - 1)) - \ + (KSTK_PTREGS_GAP - 1)) - 1) #define task_sp(task) (task_pt_regs(task)->sp) #define task_pc(task) (task_pt_regs(task)->pc) /* Aliases for pc and sp (used in fs/proc/array.c) */ diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c index d67459b..a8e5a84 100644 --- a/arch/tile/kernel/compat.c +++ b/arch/tile/kernel/compat.c @@ -103,7 +103,6 @@ long compat_sys_sched_rr_get_interval(compat_pid_t pid, #define compat_sys_readahead sys32_readahead /* Call the trampolines to manage pt_regs where necessary. */ -#define compat_sys_execve _compat_sys_execve #define compat_sys_sigaltstack _compat_sys_sigaltstack #define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn #define sys_clone _sys_clone diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 7c06d59..73f6c0a 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -1194,7 +1194,6 @@ PTREGS_SYSCALL(sys_execve, r3) PTREGS_SYSCALL(sys_sigaltstack, r2) PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0) #ifdef CONFIG_COMPAT -PTREGS_SYSCALL(compat_sys_execve, r3) PTREGS_SYSCALL(compat_sys_sigaltstack, r2) PTREGS_SYSCALL_SIGRETURN(compat_sys_rt_sigreturn, r0) #endif diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index 307d010..9dc1391 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -614,8 +614,7 @@ out: #ifdef CONFIG_COMPAT long compat_sys_execve(const char __user *path, compat_uptr_t __user *argv, - compat_uptr_t __user *envp, - struct pt_regs *regs) + compat_uptr_t __user *envp) { long error; struct filename *filename; @@ -624,7 +623,8 @@ long compat_sys_execve(const char __user *path, error = PTR_ERR(filename); if (IS_ERR(filename)) goto out; - error = compat_do_execve(filename->name, argv, envp, regs); + error = compat_do_execve(filename->name, argv, envp, + current_pt_regs()); putname(filename); if (error == 0) single_step_execve(); diff --git a/include/linux/compat.h b/include/linux/compat.h index d0ced10..d2db710 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -286,10 +286,8 @@ asmlinkage ssize_t compat_sys_pwritev(unsigned long fd, int compat_do_execve(const char *filename, const compat_uptr_t __user *argv, const compat_uptr_t __user *envp, struct pt_regs *regs); -#ifdef __ARCH_WANT_SYS_EXECVE asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr_t __user *argv, const compat_uptr_t __user *envp); -#endif asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp, compat_ulong_t __user *exp, -- 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/