diff options
Diffstat (limited to 'arch/um/os-Linux/skas/process.c')
| -rw-r--r-- | arch/um/os-Linux/skas/process.c | 190 |
1 files changed, 119 insertions, 71 deletions
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 0564422c155f..5c088a55396c 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -18,7 +18,6 @@ #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" @@ -34,6 +33,8 @@ #include "uml-config.h" #include "process.h" #include "longjmp.h" +#include "kern_constants.h" +#include "as-layout.h" int is_skas_winch(int pid, int fd, void *data) { @@ -44,45 +45,58 @@ int is_skas_winch(int pid, int fd, void *data) return(1); } -void wait_stub_done(int pid, int sig, char * fname) +static int ptrace_dump_regs(int pid) { - int n, status, err; + unsigned long regs[MAX_REG_NR]; + int i; + + if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) + return -errno; + else { + printk("Stub registers -\n"); + for(i = 0; i < ARRAY_SIZE(regs); i++) + printk("\t%d - %lx\n", i, regs[i]); + } + + return 0; +} - do { - if ( sig != -1 ) { - err = ptrace(PTRACE_CONT, pid, 0, sig); - if(err) - panic("%s : continue failed, errno = %d\n", - fname, errno); - } - sig = 0; +/* + * Signals that are OK to receive in the stub - we'll just continue it. + * SIGWINCH will happen when UML is inside a detached screen. + */ +#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH)) + +/* Signals that the stub will finish with - anything else is an error */ +#define STUB_DONE_MASK ((1 << SIGUSR1) | (1 << SIGTRAP)) + +void wait_stub_done(int pid) +{ + int n, status, err; + while(1){ 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[MAX_REG_NR]; - - 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 < ARRAY_SIZE(regs); 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); + if((n < 0) || !WIFSTOPPED(status)) + goto bad_wait; + + if(((1 << WSTOPSIG(status)) & STUB_SIG_MASK) == 0) + break; + + err = ptrace(PTRACE_CONT, pid, 0, 0); + if(err) + panic("wait_stub_done : continue failed, errno = %d\n", + errno); } + + if(((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0) + return; + +bad_wait: + err = ptrace_dump_regs(pid); + if(err) + printk("Failed to get registers from stub, errno = %d\n", -err); + panic("wait_stub_done : failed to wait for SIGUSR1/SIGTRAP, pid = %d, " + "n = %d, errno = %d, status = 0x%x\n", pid, n, errno, status); } extern unsigned long current_stub_stack(void); @@ -104,7 +118,11 @@ void get_skas_faultinfo(int pid, struct faultinfo * fi) sizeof(struct ptrace_faultinfo)); } else { - wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo"); + err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV); + if(err) + panic("Failed to continue stub, pid = %d, errno = %d\n", + pid, errno); + wait_stub_done(pid); /* faultinfo is prepared by the stub-segv-handler at start of * the stub stack page. We just have to copy it. @@ -142,9 +160,14 @@ static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED)); if((err < 0) || !WIFSTOPPED(status) || - (WSTOPSIG(status) != SIGTRAP + 0x80)) + (WSTOPSIG(status) != SIGTRAP + 0x80)){ + err = ptrace_dump_regs(pid); + if(err) + printk("Failed to get registers from process, " + "errno = %d\n", -err); panic("handle_trap - failed to wait at end of syscall, " "errno = %d, status = %d\n", errno, status); + } } handle_syscall(regs); @@ -172,7 +195,7 @@ static int userspace_tramp(void *stack) int fd; __u64 offset; fd = phys_mapping(to_phys(&__syscall_stub_start), &offset); - addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(), + addr = mmap64((void *) UML_CONFIG_STUB_CODE, UM_KERN_PAGE_SIZE, PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset); if(addr == MAP_FAILED){ printk("mapping mmap stub failed, errno = %d\n", @@ -182,8 +205,8 @@ static int userspace_tramp(void *stack) if(stack != NULL){ fd = phys_mapping(to_phys(stack), &offset); - addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(), - PROT_READ | PROT_WRITE, + addr = mmap((void *) UML_CONFIG_STUB_DATA, + UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, fd, offset); if(addr == MAP_FAILED){ printk("mapping segfault stack failed, " @@ -199,7 +222,7 @@ static int userspace_tramp(void *stack) (unsigned long) stub_segv_handler - (unsigned long) &__syscall_stub_start; - set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size()); + set_sigstack((void *) UML_CONFIG_STUB_DATA, UM_KERN_PAGE_SIZE); sigemptyset(&sa.sa_mask); sigaddset(&sa.sa_mask, SIGIO); sigaddset(&sa.sa_mask, SIGWINCH); @@ -291,10 +314,13 @@ void userspace(union uml_pt_regs *regs) UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */ if(WIFSTOPPED(status)){ - switch(WSTOPSIG(status)){ + int sig = WSTOPSIG(status); + switch(sig){ case SIGSEGV: - if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo) - user_signal(SIGSEGV, regs, pid); + if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo){ + get_skas_faultinfo(pid, ®s->skas.faultinfo); + (*sig_info[SIGSEGV])(SIGSEGV, regs); + } else handle_segv(pid, regs); break; case SIGTRAP + 0x80: @@ -309,11 +335,13 @@ void userspace(union uml_pt_regs *regs) case SIGBUS: case SIGFPE: case SIGWINCH: - user_signal(WSTOPSIG(status), regs, pid); + block_signals(); + (*sig_info[sig])(sig, regs); + unblock_signals(); break; default: printk("userspace - child stopped with signal " - "%d\n", WSTOPSIG(status)); + "%d\n", sig); } pid = userspace_pid[0]; interrupt_end(); @@ -325,11 +353,29 @@ void userspace(union uml_pt_regs *regs) } } +static unsigned long thread_regs[MAX_REG_NR]; +static unsigned long thread_fp_regs[HOST_FP_SIZE]; + +static int __init init_thread_regs(void) +{ + get_safe_registers(thread_regs, thread_fp_regs); + /* Set parent's instruction pointer to start of clone-stub */ + thread_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE + + (unsigned long) stub_clone_handler - + (unsigned long) &__syscall_stub_start; + thread_regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE - + sizeof(void *); +#ifdef __SIGNAL_FRAMESIZE + thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE; +#endif + return 0; +} + +__initcall(init_thread_regs); + int copy_context_skas0(unsigned long new_stack, int pid) { int err; - unsigned long regs[MAX_REG_NR]; - unsigned long fp_regs[HOST_FP_SIZE]; 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; @@ -344,23 +390,12 @@ int copy_context_skas0(unsigned long new_stack, int pid) .timer = ((struct itimerval) { { 0, 1000000 / hz() }, { 0, 1000000 / hz() }})}); - get_safe_registers(regs, fp_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); + err = ptrace_setregs(pid, thread_regs); if(err < 0) panic("copy_context_skas0 : PTRACE_SETREGS failed, " "pid = %d, errno = %d\n", pid, -err); - err = ptrace_setfpregs(pid, fp_regs); + err = ptrace_setfpregs(pid, thread_fp_regs); if(err < 0) panic("copy_context_skas0 : PTRACE_SETFPREGS failed, " "pid = %d, errno = %d\n", pid, -err); @@ -371,7 +406,11 @@ int copy_context_skas0(unsigned long new_stack, int pid) /* 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"); + err = ptrace(PTRACE_CONT, pid, 0, 0); + if(err) + panic("Failed to continue new process, pid = %d, " + "errno = %d\n", pid, errno); + wait_stub_done(pid); pid = data->err; if(pid < 0) @@ -381,7 +420,7 @@ int copy_context_skas0(unsigned long new_stack, int 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"); + wait_stub_done(pid); if (child_data->err != UML_CONFIG_STUB_DATA) panic("copy_context_skas0 - stub-child reports error %ld\n", child_data->err); @@ -396,7 +435,7 @@ int copy_context_skas0(unsigned long new_stack, int 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 + * available. 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, @@ -418,12 +457,13 @@ void map_stub_pages(int fd, unsigned long code, .fd = code_fd, .offset = code_offset } } }); - n = os_write_file(fd, &mmop, sizeof(mmop)); + CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); if(n != sizeof(mmop)){ + n = errno; printk("mmap args - addr = 0x%lx, fd = %d, offset = %llx\n", code, code_fd, (unsigned long long) code_offset); panic("map_stub_pages : /proc/mm map for code failed, " - "err = %d\n", -n); + "err = %d\n", n); } if ( stack ) { @@ -440,10 +480,10 @@ void map_stub_pages(int fd, unsigned long code, .fd = map_fd, .offset = map_offset } } }); - n = os_write_file(fd, &mmop, sizeof(mmop)); + CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); if(n != sizeof(mmop)) panic("map_stub_pages : /proc/mm map for data failed, " - "err = %d\n", -n); + "err = %d\n", errno); } } @@ -480,7 +520,15 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf) SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM, SIGVTALRM, -1); - n = UML_SETJMP(&initial_jmpbuf); + /* + * Can't use UML_SETJMP or UML_LONGJMP here because they save + * and restore signals, with the possible side-effect of + * trying to handle any signals which came when they were + * blocked, which can't be done on this stack. + * Signals must be blocked when jumping back here and restored + * after returning to the jumper. + */ + n = setjmp(initial_jmpbuf); switch(n){ case INIT_JMP_NEW_THREAD: (*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler; @@ -490,7 +538,7 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf) break; case INIT_JMP_CALLBACK: (*cb_proc)(cb_arg); - UML_LONGJMP(cb_back, 1); + longjmp(*cb_back, 1); break; case INIT_JMP_HALT: kmalloc_ok = 0; @@ -501,7 +549,7 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf) default: panic("Bad sigsetjmp return in start_idle_thread - %d\n", n); } - UML_LONGJMP(switch_buf, 1); + longjmp(*switch_buf, 1); } void initial_thread_cb_skas(void (*proc)(void *), void *arg) |