From e0e431aa45416982eb3fddf34cedc72f1c3b3ce3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 18 Oct 2012 01:11:58 -0400 Subject: alpha: simplify fork and friends * no need to restore everything from switch_stack when we only need $26 * no need to pass current_pt_regs() manually, we can just as easily calculate it in alpha_clone/alpha_vfork ($8 + constant) * interpretation of zero usp as "use the parent's" is simpler in copy_thread(); let fork and vfork just pass 0. Signed-off-by: Al Viro --- arch/alpha/kernel/entry.S | 17 +++++++---------- arch/alpha/kernel/process.c | 16 +++++++--------- 2 files changed, 14 insertions(+), 19 deletions(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index a760783..cc6d34e 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -617,7 +617,6 @@ ret_from_kernel_thread: .ent sys_fork sys_fork: .prologue 0 - mov $sp, $21 bsr $1, do_switch_stack bis $31, SIGCHLD, $16 mov $31, $17 @@ -625,7 +624,9 @@ sys_fork: mov $31, $19 mov $31, $20 jsr $26, alpha_clone - bsr $1, undo_switch_stack +fork_out: + ldq $26, 56($sp) + lda $sp, SWITCH_STACK_SIZE($sp) ret .end sys_fork @@ -634,12 +635,10 @@ sys_fork: .ent sys_clone sys_clone: .prologue 0 - mov $sp, $21 bsr $1, do_switch_stack /* $16, $17, $18, $19, $20 come from the user. */ - jsr $26, alpha_clone - bsr $1, undo_switch_stack - ret + lda $26, fork_out + jsr $31, alpha_clone .end sys_clone .align 4 @@ -647,11 +646,9 @@ sys_clone: .ent sys_vfork sys_vfork: .prologue 0 - mov $sp, $16 bsr $1, do_switch_stack - jsr $26, alpha_vfork - bsr $1, undo_switch_stack - ret + lda $26, fork_out + jsr $31, alpha_vfork .end sys_vfork .align 4 diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 51987dc..ad86c09 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -246,19 +246,17 @@ release_thread(struct task_struct *dead_task) int alpha_clone(unsigned long clone_flags, unsigned long usp, int __user *parent_tid, int __user *child_tid, - unsigned long tls_value, struct pt_regs *regs) + unsigned long tls_value) { - if (!usp) - usp = rdusp(); - - return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid); + return do_fork(clone_flags, usp, current_pt_regs(), 0, + parent_tid, child_tid); } int -alpha_vfork(struct pt_regs *regs) +alpha_vfork(void) { - return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), - regs, 0, NULL, NULL); + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0, + current_pt_regs(), 0, NULL, NULL); } /* @@ -301,7 +299,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp, stack = ((struct switch_stack *) regs) - 1; *childstack = *stack; childstack->r26 = (unsigned long) ret_from_fork; - childti->pcb.usp = usp; + childti->pcb.usp = usp ?: rdusp(); childti->pcb.ksp = (unsigned long) childstack; childti->pcb.flags = 1; /* set FEN, clear everything else */ -- cgit v1.1 From b960f303448969c6cb76b4df9291e9e6213e2b9f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 18 Oct 2012 01:43:27 -0400 Subject: alpha: don't pass useless arguments to do_{,rt_},sigreturn() Signed-off-by: Al Viro --- arch/alpha/kernel/entry.S | 4 ---- arch/alpha/kernel/signal.c | 16 ++++++++-------- 2 files changed, 8 insertions(+), 12 deletions(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index cc6d34e..c245de6 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -658,8 +658,6 @@ sys_sigreturn: .prologue 0 lda $9, ret_from_straced cmpult $26, $9, $9 - mov $sp, $17 - lda $18, -SWITCH_STACK_SIZE($sp) lda $sp, -SWITCH_STACK_SIZE($sp) jsr $26, do_sigreturn bne $9, 1f @@ -675,8 +673,6 @@ sys_rt_sigreturn: .prologue 0 lda $9, ret_from_straced cmpult $26, $9, $9 - mov $sp, $17 - lda $18, -SWITCH_STACK_SIZE($sp) lda $sp, -SWITCH_STACK_SIZE($sp) jsr $26, do_rt_sigreturn bne $9, 1f diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c index 32575f8..336393c 100644 --- a/arch/alpha/kernel/signal.c +++ b/arch/alpha/kernel/signal.c @@ -160,10 +160,10 @@ extern char compile_time_assert #define INSN_CALLSYS 0x00000083 static long -restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, - struct switch_stack *sw) +restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) { unsigned long usp; + struct switch_stack *sw = (struct switch_stack *)regs - 1; long i, err = __get_user(regs->pc, &sc->sc_pc); current_thread_info()->restart_block.fn = do_no_restart_syscall; @@ -215,9 +215,9 @@ restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, registers and transfer control from userland. */ asmlinkage void -do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs, - struct switch_stack *sw) +do_sigreturn(struct sigcontext __user *sc) { + struct pt_regs *regs = current_pt_regs(); sigset_t set; /* Verify that it's a good sigcontext before using it */ @@ -228,7 +228,7 @@ do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs, set_current_blocked(&set); - if (restore_sigcontext(sc, regs, sw)) + if (restore_sigcontext(sc, regs)) goto give_sigsegv; /* Send SIGTRAP if we're single-stepping: */ @@ -249,9 +249,9 @@ give_sigsegv: } asmlinkage void -do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs, - struct switch_stack *sw) +do_rt_sigreturn(struct rt_sigframe __user *frame) { + struct pt_regs *regs = current_pt_regs(); sigset_t set; /* Verify that it's a good ucontext_t before using it */ @@ -262,7 +262,7 @@ do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs, set_current_blocked(&set); - if (restore_sigcontext(&frame->uc.uc_mcontext, regs, sw)) + if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) goto give_sigsegv; /* Send SIGTRAP if we're single-stepping: */ -- cgit v1.1 From 25906730ec01be664534c9439d7cf5a373e8a4e4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 21 Oct 2012 15:52:04 -0400 Subject: alpha: reorganize copy_process(), prepare to saner fork_idle() Signed-off-by: Al Viro --- arch/alpha/kernel/process.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index ad86c09..a4dc79ba 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -266,18 +266,22 @@ alpha_vfork(void) int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, - struct task_struct * p, struct pt_regs * regs) + struct task_struct *p, struct pt_regs *wontuse) { extern void ret_from_fork(void); extern void ret_from_kernel_thread(void); struct thread_info *childti = task_thread_info(p); struct pt_regs *childregs = task_pt_regs(p); + struct pt_regs *regs = current_pt_regs(); struct switch_stack *childstack, *stack; unsigned long settls; childstack = ((struct switch_stack *) childregs) - 1; - if (unlikely(!regs)) { + childti->pcb.ksp = (unsigned long) childstack; + childti->pcb.flags = 1; /* set FEN, clear everything else */ + + if (unlikely(p->flags & PF_KTHREAD)) { /* kernel thread */ memset(childstack, 0, sizeof(struct switch_stack) + sizeof(struct pt_regs)); @@ -286,12 +290,17 @@ copy_thread(unsigned long clone_flags, unsigned long usp, childstack->r10 = arg; childregs->hae = alpha_mv.hae_cache, childti->pcb.usp = 0; - childti->pcb.ksp = (unsigned long) childstack; - childti->pcb.flags = 1; /* set FEN, clear everything else */ return 0; } + /* Note: if CLONE_SETTLS is not set, then we must inherit the + value from the parent, which will have been set by the block + copy in dup_task_struct. This is non-intuitive, but is + required for proper operation in the case of a threaded + application calling fork. */ + if (clone_flags & CLONE_SETTLS) + childti->pcb.unique = regs->r20; + childti->pcb.usp = usp ?: rdusp(); *childregs = *regs; - settls = regs->r20; childregs->r0 = 0; childregs->r19 = 0; childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */ @@ -299,22 +308,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp, stack = ((struct switch_stack *) regs) - 1; *childstack = *stack; childstack->r26 = (unsigned long) ret_from_fork; - childti->pcb.usp = usp ?: rdusp(); - childti->pcb.ksp = (unsigned long) childstack; - childti->pcb.flags = 1; /* set FEN, clear everything else */ - - /* Set a new TLS for the child thread? Peek back into the - syscall arguments that we saved on syscall entry. Oops, - except we'd have clobbered it with the parent/child set - of r20. Read the saved copy. */ - /* Note: if CLONE_SETTLS is not set, then we must inherit the - value from the parent, which will have been set by the block - copy in dup_task_struct. This is non-intuitive, but is - required for proper operation in the case of a threaded - application calling fork. */ - if (clone_flags & CLONE_SETTLS) - childti->pcb.unique = settls; - return 0; } -- cgit v1.1 From 3c456bfc4ba66e9cda210da7bc4fb0ba9fcc6972 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 20 Oct 2012 21:53:31 -0400 Subject: get rid of pt_regs argument of search_binary_handler() Signed-off-by: Al Viro --- arch/alpha/kernel/binfmt_loader.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/binfmt_loader.c b/arch/alpha/kernel/binfmt_loader.c index d1f474d..54abbef 100644 --- a/arch/alpha/kernel/binfmt_loader.c +++ b/arch/alpha/kernel/binfmt_loader.c @@ -37,7 +37,7 @@ static int load_binary(struct linux_binprm *bprm, struct pt_regs *regs) retval = prepare_binprm(bprm); if (retval < 0) return retval; - return search_binary_handler(bprm,regs); + return search_binary_handler(bprm); } static struct linux_binfmt loader_format = { -- cgit v1.1 From 71613c3b871c5a9f27cc48f124251bcd3aa23be1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 20 Oct 2012 22:00:48 -0400 Subject: get rid of pt_regs argument of ->load_binary() Signed-off-by: Al Viro --- arch/alpha/kernel/binfmt_loader.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/binfmt_loader.c b/arch/alpha/kernel/binfmt_loader.c index 54abbef..9525660 100644 --- a/arch/alpha/kernel/binfmt_loader.c +++ b/arch/alpha/kernel/binfmt_loader.c @@ -5,7 +5,7 @@ #include #include -static int load_binary(struct linux_binprm *bprm, struct pt_regs *regs) +static int load_binary(struct linux_binprm *bprm) { struct exec *eh = (struct exec *)bprm->buf; unsigned long loader; -- cgit v1.1 From dfe09ae0e5fe40679af05b1ba810d469844c97b3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 26 Oct 2012 09:54:47 -0400 Subject: alpha: switch to generic fork/vfork/clone Signed-off-by: Al Viro --- arch/alpha/kernel/entry.S | 42 +++++++++++------------------------------- arch/alpha/kernel/process.c | 25 ------------------------- arch/alpha/kernel/systbls.S | 6 +++--- 3 files changed, 14 insertions(+), 59 deletions(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index c245de6..f62a994 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -612,44 +612,24 @@ ret_from_kernel_thread: * Special system calls. Most of these are special in that they either * have to play switch_stack games or in some way use the pt_regs struct. */ + +.macro fork_like name .align 4 - .globl sys_fork - .ent sys_fork -sys_fork: + .globl alpha_\name + .ent alpha_\name +alpha_\name: .prologue 0 bsr $1, do_switch_stack - bis $31, SIGCHLD, $16 - mov $31, $17 - mov $31, $18 - mov $31, $19 - mov $31, $20 - jsr $26, alpha_clone -fork_out: + jsr $26, sys_\name ldq $26, 56($sp) lda $sp, SWITCH_STACK_SIZE($sp) ret -.end sys_fork - - .align 4 - .globl sys_clone - .ent sys_clone -sys_clone: - .prologue 0 - bsr $1, do_switch_stack - /* $16, $17, $18, $19, $20 come from the user. */ - lda $26, fork_out - jsr $31, alpha_clone -.end sys_clone +.end alpha_\name +.endm - .align 4 - .globl sys_vfork - .ent sys_vfork -sys_vfork: - .prologue 0 - bsr $1, do_switch_stack - lda $26, fork_out - jsr $31, alpha_vfork -.end sys_vfork +fork_like fork +fork_like vfork +fork_like clone .align 4 .globl sys_sigreturn diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index a4dc79ba..e9705bc 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -235,31 +235,6 @@ release_thread(struct task_struct *dead_task) } /* - * "alpha_clone()".. By the time we get here, the - * non-volatile registers have also been saved on the - * stack. We do some ugly pointer stuff here.. (see - * also copy_thread) - * - * Notice that "fork()" is implemented in terms of clone, - * with parameters (SIGCHLD, 0). - */ -int -alpha_clone(unsigned long clone_flags, unsigned long usp, - int __user *parent_tid, int __user *child_tid, - unsigned long tls_value) -{ - return do_fork(clone_flags, usp, current_pt_regs(), 0, - parent_tid, child_tid); -} - -int -alpha_vfork(void) -{ - return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0, - current_pt_regs(), 0, NULL, NULL); -} - -/* * Copy an alpha thread.. */ diff --git a/arch/alpha/kernel/systbls.S b/arch/alpha/kernel/systbls.S index 2ac6b45..4284ec7 100644 --- a/arch/alpha/kernel/systbls.S +++ b/arch/alpha/kernel/systbls.S @@ -12,7 +12,7 @@ sys_call_table: .quad alpha_ni_syscall /* 0 */ .quad sys_exit - .quad sys_fork + .quad alpha_fork .quad sys_read .quad sys_write .quad alpha_ni_syscall /* 5 */ @@ -76,7 +76,7 @@ sys_call_table: .quad sys_getpgrp .quad sys_getpagesize .quad alpha_ni_syscall /* 65 */ - .quad sys_vfork + .quad alpha_vfork .quad sys_newstat .quad sys_newlstat .quad alpha_ni_syscall @@ -330,7 +330,7 @@ sys_call_table: .quad sys_ni_syscall /* 309: old get_kernel_syms */ .quad sys_syslog /* 310 */ .quad sys_reboot - .quad sys_clone + .quad alpha_clone .quad sys_uselib .quad sys_mlock .quad sys_munlock /* 315 */ -- cgit v1.1 From afa86fc426ff7e7f5477f15da9c405d08d5cf790 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 22 Oct 2012 22:51:14 -0400 Subject: flagday: don't pass regs to copy_thread() Signed-off-by: Al Viro --- arch/alpha/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/alpha/kernel') diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index e9705bc..b5d0d09 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -241,7 +241,7 @@ release_thread(struct task_struct *dead_task) int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, - struct task_struct *p, struct pt_regs *wontuse) + struct task_struct *p) { extern void ret_from_fork(void); extern void ret_from_kernel_thread(void); -- cgit v1.1