diff options
Diffstat (limited to 'arch/um/os-Linux')
| -rw-r--r-- | arch/um/os-Linux/signal.c | 5 | ||||
| -rw-r--r-- | arch/um/os-Linux/skas/Makefile | 4 | ||||
| -rw-r--r-- | arch/um/os-Linux/skas/process.c | 565 |
3 files changed, 572 insertions, 2 deletions
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index 884e4575194..56ca95931b4 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -194,3 +194,8 @@ int set_signals(int enable) return(ret); } + +void os_usr1_signal(int on) +{ + change_sig(SIGUSR1, on); +} diff --git a/arch/um/os-Linux/skas/Makefile b/arch/um/os-Linux/skas/Makefile index 79cc6c72aa9..5fd8d4dad66 100644 --- a/arch/um/os-Linux/skas/Makefile +++ b/arch/um/os-Linux/skas/Makefile @@ -3,8 +3,8 @@ # Licensed under the GPL # -obj-y := mem.o trap.o +obj-y := mem.o process.o trap.o -USER_OBJS := mem.o trap.o +USER_OBJS := mem.o process.o trap.o include arch/um/scripts/Makefile.rules diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c new file mode 100644 index 00000000000..f787854322c --- /dev/null +++ b/arch/um/os-Linux/skas/process.c @@ -0,0 +1,565 @@ +/* + * Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com) + * Licensed under the GPL + */ + +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <signal.h> +#include <setjmp.h> +#include <sched.h> +#include "ptrace_user.h" +#include <sys/wait.h> +#include <sys/mman.h> +#include <sys/user.h> +#include <sys/time.h> +#include <asm/unistd.h> +#include <asm/types.h> +#include "user.h" +#include "sysdep/ptrace.h" +#include "user_util.h" +#include "kern_util.h" +#include "skas.h" +#include "stub-data.h" +#include "mm_id.h" +#include "sysdep/sigcontext.h" +#include "sysdep/stub.h" +#include "os.h" +#include "proc_mm.h" +#include "skas_ptrace.h" +#include "chan_user.h" +#include "registers.h" +#include "mem.h" +#include "uml-config.h" +#include "process.h" + +int is_skas_winch(int pid, int fd, void *data) +{ + if(pid != os_getpgrp()) + return(0); + + register_winch_irq(-1, fd, -1, data); + return(1); +} + +void wait_stub_done(int pid, int sig, char * fname) +{ + int n, status, err; + + do { + if ( sig != -1 ) { + err = ptrace(PTRACE_CONT, pid, 0, sig); + if(err) + panic("%s : continue failed, errno = %d\n", + fname, errno); + } + sig = 0; + + CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); + } while((n >= 0) && WIFSTOPPED(status) && + ((WSTOPSIG(status) == SIGVTALRM) || + /* running UML inside a detached screen can cause + * SIGWINCHes + */ + (WSTOPSIG(status) == SIGWINCH))); + + if((n < 0) || !WIFSTOPPED(status) || + (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){ + unsigned long regs[HOST_FRAME_SIZE]; + + if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) + printk("Failed to get registers from stub, " + "errno = %d\n", errno); + else { + int i; + + printk("Stub registers -\n"); + for(i = 0; i < HOST_FRAME_SIZE; i++) + printk("\t%d - %lx\n", i, regs[i]); + } + panic("%s : failed to wait for SIGUSR1/SIGTRAP, " + "pid = %d, n = %d, errno = %d, status = 0x%x\n", + fname, pid, n, errno, status); + } +} + +extern unsigned long current_stub_stack(void); + +void get_skas_faultinfo(int pid, struct faultinfo * fi) +{ + int err; + + if(ptrace_faultinfo){ + err = ptrace(PTRACE_FAULTINFO, pid, 0, fi); + if(err) + panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, " + "errno = %d\n", errno); + + /* Special handling for i386, which has different structs */ + if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo)) + memset((char *)fi + sizeof(struct ptrace_faultinfo), 0, + sizeof(struct faultinfo) - + sizeof(struct ptrace_faultinfo)); + } + else { + wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo"); + + /* faultinfo is prepared by the stub-segv-handler at start of + * the stub stack page. We just have to copy it. + */ + memcpy(fi, (void *)current_stub_stack(), sizeof(*fi)); + } +} + +static void handle_segv(int pid, union uml_pt_regs * regs) +{ + get_skas_faultinfo(pid, ®s->skas.faultinfo); + segv(regs->skas.faultinfo, 0, 1, NULL); +} + +/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/ +static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu) +{ + int err, status; + + /* Mark this as a syscall */ + UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs); + + if (!local_using_sysemu) + { + err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, + __NR_getpid); + if(err < 0) + panic("handle_trap - nullifying syscall failed errno = %d\n", + errno); + + err = ptrace(PTRACE_SYSCALL, pid, 0, 0); + if(err < 0) + panic("handle_trap - continuing to end of syscall failed, " + "errno = %d\n", errno); + + CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED)); + if((err < 0) || !WIFSTOPPED(status) || + (WSTOPSIG(status) != SIGTRAP + 0x80)) + panic("handle_trap - failed to wait at end of syscall, " + "errno = %d, status = %d\n", errno, status); + } + + handle_syscall(regs); +} + +extern int __syscall_stub_start; +int stub_code_fd = -1; +__u64 stub_code_offset; + +static int userspace_tramp(void *stack) +{ + void *addr; + + ptrace(PTRACE_TRACEME, 0, 0, 0); + + init_new_thread_signals(1); + enable_timer(); + + if(!proc_mm){ + /* This has a pte, but it can't be mapped in with the usual + * tlb_flush mechanism because this is part of that mechanism + */ + addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(), + PROT_EXEC, MAP_FIXED | MAP_PRIVATE, + stub_code_fd, stub_code_offset); + if(addr == MAP_FAILED){ + printk("mapping stub code failed, errno = %d\n", + errno); + exit(1); + } + + if(stack != NULL){ + int fd; + __u64 offset; + fd = phys_mapping(to_phys(stack), &offset); + addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(), + PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_SHARED, fd, offset); + if(addr == MAP_FAILED){ + printk("mapping stub stack failed, " + "errno = %d\n", errno); + exit(1); + } + } + } + if(!ptrace_faultinfo){ + unsigned long v = UML_CONFIG_STUB_CODE + + (unsigned long) stub_segv_handler - + (unsigned long) &__syscall_stub_start; + + set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size()); + set_handler(SIGSEGV, (void *) v, SA_ONSTACK, + SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, + SIGUSR1, -1); + } + + os_stop_process(os_getpid()); + return(0); +} + +/* Each element set once, and only accessed by a single processor anyway */ +#undef NR_CPUS +#define NR_CPUS 1 +int userspace_pid[NR_CPUS]; + +int start_userspace(unsigned long stub_stack) +{ + void *stack; + unsigned long sp; + int pid, status, n, flags; + + if ( stub_code_fd == -1 ) + stub_code_fd = phys_mapping(to_phys(&__syscall_stub_start), + &stub_code_offset); + + stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if(stack == MAP_FAILED) + panic("start_userspace : mmap failed, errno = %d", errno); + sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); + + flags = CLONE_FILES | SIGCHLD; + if(proc_mm) flags |= CLONE_VM; + pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack); + if(pid < 0) + panic("start_userspace : clone failed, errno = %d", errno); + + do { + CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); + if(n < 0) + panic("start_userspace : wait failed, errno = %d", + errno); + } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM)); + + if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) + panic("start_userspace : expected SIGSTOP, got status = %d", + status); + + if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0) + panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n", + errno); + + if(munmap(stack, PAGE_SIZE) < 0) + panic("start_userspace : munmap failed, errno = %d\n", errno); + + return(pid); +} + +void userspace(union uml_pt_regs *regs) +{ + int err, status, op, pid = userspace_pid[0]; + int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/ + + while(1){ + restore_registers(pid, regs); + + /* Now we set local_using_sysemu to be used for one loop */ + local_using_sysemu = get_using_sysemu(); + + op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL)); + + err = ptrace(op, pid, 0, 0); + if(err) + panic("userspace - could not resume userspace process, " + "pid=%d, ptrace operation = %d, errno = %d\n", + op, errno); + + CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED)); + if(err < 0) + panic("userspace - waitpid failed, errno = %d\n", + errno); + + regs->skas.is_user = 1; + save_registers(pid, regs); + UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */ + + if(WIFSTOPPED(status)){ + switch(WSTOPSIG(status)){ + case SIGSEGV: + if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo) + user_signal(SIGSEGV, regs, pid); + else handle_segv(pid, regs); + break; + case SIGTRAP + 0x80: + handle_trap(pid, regs, local_using_sysemu); + break; + case SIGTRAP: + relay_signal(SIGTRAP, regs); + break; + case SIGIO: + case SIGVTALRM: + case SIGILL: + case SIGBUS: + case SIGFPE: + case SIGWINCH: + user_signal(WSTOPSIG(status), regs, pid); + break; + default: + printk("userspace - child stopped with signal " + "%d\n", WSTOPSIG(status)); + } + again: + pid = userspace_pid[0]; + interrupt_end(); + + /* Avoid -ERESTARTSYS handling in host */ + if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET) + PT_SYSCALL_NR(regs->skas.regs) = -1; + } + } +} +#define INIT_JMP_NEW_THREAD 0 +#define INIT_JMP_REMOVE_SIGSTACK 1 +#define INIT_JMP_CALLBACK 2 +#define INIT_JMP_HALT 3 +#define INIT_JMP_REBOOT 4 + +int copy_context_skas0(unsigned long new_stack, int pid) +{ + int err; + unsigned long regs[MAX_REG_NR]; + unsigned long current_stack = current_stub_stack(); + struct stub_data *data = (struct stub_data *) current_stack; + struct stub_data *child_data = (struct stub_data *) new_stack; + __u64 new_offset; + int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset); + + /* prepare offset and fd of child's stack as argument for parent's + * and child's mmap2 calls + */ + *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset), + .fd = new_fd, + .timer = ((struct itimerval) + { { 0, 1000000 / hz() }, + { 0, 1000000 / hz() }})}); + get_safe_registers(regs); + + /* Set parent's instruction pointer to start of clone-stub */ + regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE + + (unsigned long) stub_clone_handler - + (unsigned long) &__syscall_stub_start; + regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE - + sizeof(void *); +#ifdef __SIGNAL_FRAMESIZE + regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE; +#endif + err = ptrace_setregs(pid, regs); + if(err < 0) + panic("copy_context_skas0 : PTRACE_SETREGS failed, " + "pid = %d, errno = %d\n", pid, errno); + + /* set a well known return code for detection of child write failure */ + child_data->err = 12345678; + + /* Wait, until parent has finished its work: read child's pid from + * parent's stack, and check, if bad result. + */ + wait_stub_done(pid, 0, "copy_context_skas0"); + + pid = data->err; + if(pid < 0) + panic("copy_context_skas0 - stub-parent reports error %d\n", + pid); + + /* Wait, until child has finished too: read child's result from + * child's stack and check it. + */ + wait_stub_done(pid, -1, "copy_context_skas0"); + if (child_data->err != UML_CONFIG_STUB_DATA) + panic("copy_context_skas0 - stub-child reports error %d\n", + child_data->err); + + if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, + (void *)PTRACE_O_TRACESYSGOOD) < 0) + panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, " + "errno = %d\n", errno); + + return pid; +} + +/* + * This is used only, if stub pages are needed, while proc_mm is + * availabl. Opening /proc/mm creates a new mm_context, which lacks + * the stub-pages. Thus, we map them using /proc/mm-fd + */ +void map_stub_pages(int fd, unsigned long code, + unsigned long data, unsigned long stack) +{ + struct proc_mm_op mmop; + int n; + + mmop = ((struct proc_mm_op) { .op = MM_MMAP, + .u = + { .mmap = + { .addr = code, + .len = PAGE_SIZE, + .prot = PROT_EXEC, + .flags = MAP_FIXED | MAP_PRIVATE, + .fd = stub_code_fd, + .offset = stub_code_offset + } } }); + n = os_write_file(fd, &mmop, sizeof(mmop)); + if(n != sizeof(mmop)) + panic("map_stub_pages : /proc/mm map for code failed, " + "err = %d\n", -n); + + if ( stack ) { + __u64 map_offset; + int map_fd = phys_mapping(to_phys((void *)stack), &map_offset); + mmop = ((struct proc_mm_op) + { .op = MM_MMAP, + .u = + { .mmap = + { .addr = data, + .len = PAGE_SIZE, + .prot = PROT_READ | PROT_WRITE, + .flags = MAP_FIXED | MAP_SHARED, + .fd = map_fd, + .offset = map_offset + } } }); + n = os_write_file(fd, &mmop, sizeof(mmop)); + if(n != sizeof(mmop)) + panic("map_stub_pages : /proc/mm map for data failed, " + "err = %d\n", -n); + } +} + +void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr, + void (*handler)(int)) +{ + unsigned long flags; + sigjmp_buf switch_buf, fork_buf; + + *switch_buf_ptr = &switch_buf; + *fork_buf_ptr = &fork_buf; + + /* Somewhat subtle - siglongjmp restores the signal mask before doing + * the longjmp. This means that when jumping from one stack to another + * when the target stack has interrupts enabled, an interrupt may occur + * on the source stack. This is bad when starting up a process because + * it's not supposed to get timer ticks until it has been scheduled. + * So, we disable interrupts around the sigsetjmp to ensure that + * they can't happen until we get back here where they are safe. + */ + flags = get_signals(); + block_signals(); + if(sigsetjmp(fork_buf, 1) == 0) + new_thread_proc(stack, handler); + + remove_sigstack(); + + set_signals(flags); +} + +void thread_wait(void *sw, void *fb) +{ + sigjmp_buf buf, **switch_buf = sw, *fork_buf; + + *switch_buf = &buf; + fork_buf = fb; + if(sigsetjmp(buf, 1) == 0) + siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK); +} + +void switch_threads(void *me, void *next) +{ + sigjmp_buf my_buf, **me_ptr = me, *next_buf = next; + + *me_ptr = &my_buf; + if(sigsetjmp(my_buf, 1) == 0) + siglongjmp(*next_buf, 1); +} + +static sigjmp_buf initial_jmpbuf; + +/* XXX Make these percpu */ +static void (*cb_proc)(void *arg); +static void *cb_arg; +static sigjmp_buf *cb_back; + +int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr) +{ + sigjmp_buf **switch_buf = switch_buf_ptr; + int n; + + set_handler(SIGWINCH, (__sighandler_t) sig_handler, + SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM, + SIGVTALRM, -1); + + *fork_buf_ptr = &initial_jmpbuf; + n = sigsetjmp(initial_jmpbuf, 1); + switch(n){ + case INIT_JMP_NEW_THREAD: + new_thread_proc((void *) stack, new_thread_handler); + break; + case INIT_JMP_REMOVE_SIGSTACK: + remove_sigstack(); + break; + case INIT_JMP_CALLBACK: + (*cb_proc)(cb_arg); + siglongjmp(*cb_back, 1); + break; + case INIT_JMP_HALT: + kmalloc_ok = 0; + return(0); + case INIT_JMP_REBOOT: + kmalloc_ok = 0; + return(1); + default: + panic("Bad sigsetjmp return in start_idle_thread - %d\n", n); + } + siglongjmp(**switch_buf, 1); +} + +void initial_thread_cb_skas(void (*proc)(void *), void *arg) +{ + sigjmp_buf here; + + cb_proc = proc; + cb_arg = arg; + cb_back = &here; + + block_signals(); + if(sigsetjmp(here, 1) == 0) + siglongjmp(initial_jmpbuf, INIT_JMP_CALLBACK); + unblock_signals(); + + cb_proc = NULL; + cb_arg = NULL; + cb_back = NULL; +} + +void halt_skas(void) +{ + block_signals(); + siglongjmp(initial_jmpbuf, INIT_JMP_HALT); +} + +void reboot_skas(void) +{ + block_signals(); + siglongjmp(initial_jmpbuf, INIT_JMP_REBOOT); +} + +void switch_mm_skas(struct mm_id *mm_idp) +{ + int err; + +#warning need cpu pid in switch_mm_skas + if(proc_mm){ + err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, + mm_idp->u.mm_fd); + if(err) + panic("switch_mm_skas - PTRACE_SWITCH_MM failed, " + "errno = %d\n", errno); + } + else userspace_pid[0] = mm_idp->u.pid; +} |