From 60d339f6fe0831060600c62418b71a62ad26c281 Mon Sep 17 00:00:00 2001 From: Gennady Sharapov Date: Sat, 3 Sep 2005 15:57:47 -0700 Subject: [PATCH] uml: move libc-dependent startup and signal code The serial UML OS-abstraction layer patch (um/kernel dir). This moves all systemcalls from process.c file under os-Linux dir and join process.c and process_kern.c files. Signed-off-by: Gennady Sharapov Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/include/os.h | 15 ++ arch/um/include/user_util.h | 8 - arch/um/kernel/Makefile | 13 +- arch/um/kernel/process.c | 439 -------------------------------------------- arch/um/kernel/um_arch.c | 2 +- arch/um/os-Linux/Makefile | 7 +- arch/um/os-Linux/process.c | 58 +++++- arch/um/os-Linux/start_up.c | 329 +++++++++++++++++++++++++++++++++ arch/um/os-Linux/tt.c | 113 ++++++++++++ 9 files changed, 523 insertions(+), 461 deletions(-) delete mode 100644 arch/um/kernel/process.c create mode 100644 arch/um/os-Linux/start_up.c create mode 100644 arch/um/os-Linux/tt.c (limited to 'arch/um') diff --git a/arch/um/include/os.h b/arch/um/include/os.h index 881d2988d2d8..4c362458052c 100644 --- a/arch/um/include/os.h +++ b/arch/um/include/os.h @@ -153,6 +153,11 @@ extern int os_file_type(char *file); extern int os_file_mode(char *file, struct openflags *mode_out); extern int os_lock_file(int fd, int excl); +/* start_up.c */ +extern void os_early_checks(void); +extern int can_do_skas(void); + +/* process.c */ extern unsigned long os_process_pc(int pid); extern int os_process_parent(int pid); extern void os_stop_process(int pid); @@ -161,6 +166,9 @@ extern void os_kill_ptraced_process(int pid, int reap_child); extern void os_usr1_process(int pid); extern int os_getpid(void); extern int os_getpgrp(void); +extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)); +extern void init_new_thread_signals(int altstack); +extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr); extern int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len, int r, int w, int x); @@ -170,6 +178,13 @@ extern int os_unmap_memory(void *addr, int len); extern void os_flush_stdout(void); extern unsigned long long os_usecs(void); +/* tt.c + * for tt mode only (will be deleted in future...) + */ +extern void forward_pending_sigio(int target); +extern int start_fork_tramp(void *arg, unsigned long temp_stack, + int clone_flags, int (*tramp)(void *)); + #endif /* diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h index 7b6a24dfd302..bb505e01d994 100644 --- a/arch/um/include/user_util.h +++ b/arch/um/include/user_util.h @@ -54,8 +54,6 @@ extern void stack_protections(unsigned long address); extern void task_protections(unsigned long address); extern int wait_for_stop(int pid, int sig, int cont_type, void *relay); extern void *add_signal_handler(int sig, void (*handler)(int)); -extern int start_fork_tramp(void *arg, unsigned long temp_stack, - int clone_flags, int (*tramp)(void *)); extern int linux_main(int argc, char **argv); extern void set_cmdline(char *cmd); extern void input_cb(void (*proc)(void *), void *arg, int arg_len); @@ -64,8 +62,6 @@ extern void *um_kmalloc(int size); extern int switcheroo(int fd, int prot, void *from, void *to, int size); extern void setup_machinename(char *machine_out); extern void setup_hostinfo(void); -extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)); -extern void init_new_thread_signals(int altstack); extern void do_exec(int old_pid, int new_pid); extern void tracer_panic(char *msg, ...); extern char *get_umid(int only_if_set); @@ -74,16 +70,12 @@ extern int detach(int pid, int sig); extern int attach(int pid); extern void kill_child_dead(int pid); extern int cont(int pid); -extern void check_ptrace(void); extern void check_sigio(void); -extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr); extern void write_sigio_workaround(void); extern void arch_check_bugs(void); extern int cpu_feature(char *what, char *buf, int len); extern int arch_handle_signal(int sig, union uml_pt_regs *regs); extern int arch_fixup(unsigned long address, void *sc_ptr); -extern void forward_pending_sigio(int target); -extern int can_do_skas(void); extern void arch_init_thread(void); extern int setjmp_wrapper(void (*proc)(void *, void *), ...); extern int raw(int fd); diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile index a9cdd00775a3..614b8ebeb0ed 100644 --- a/arch/um/kernel/Makefile +++ b/arch/um/kernel/Makefile @@ -8,11 +8,10 @@ clean-files := obj-y = config.o exec_kern.o exitcode.o \ helper.o init_task.o irq.o irq_user.o ksyms.o main.o mem.o mem_user.o \ - physmem.o process.o process_kern.o ptrace.o reboot.o resource.o \ - sigio_user.o sigio_kern.o signal_kern.o signal_user.o smp.o \ - syscall_kern.o sysrq.o tempfile.o time.o time_kern.o \ - tlb.o trap_kern.o trap_user.o uaccess_user.o um_arch.o umid.o \ - user_util.o + physmem.o process_kern.o ptrace.o reboot.o resource.o sigio_user.o \ + sigio_kern.o signal_kern.o signal_user.o smp.o syscall_kern.o sysrq.o \ + tempfile.o time.o time_kern.o tlb.o trap_kern.o trap_user.o \ + uaccess_user.o um_arch.o umid.o user_util.o obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o obj-$(CONFIG_GPROF) += gprof_syms.o @@ -25,8 +24,8 @@ obj-$(CONFIG_MODE_SKAS) += skas/ user-objs-$(CONFIG_TTY_LOG) += tty_log.o -USER_OBJS := $(user-objs-y) config.o helper.o main.o process.o tempfile.o \ - time.o tty_log.o umid.o user_util.o +USER_OBJS := $(user-objs-y) config.o helper.o main.o tempfile.o time.o \ + tty_log.o umid.o user_util.o include arch/um/scripts/Makefile.rules diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c deleted file mode 100644 index 67acd92c5322..000000000000 --- a/arch/um/kernel/process.c +++ /dev/null @@ -1,439 +0,0 @@ -/* - * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) - * Licensed under the GPL - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "user_util.h" -#include "kern_util.h" -#include "user.h" -#include "process.h" -#include "signal_kern.h" -#include "signal_user.h" -#include "sysdep/ptrace.h" -#include "sysdep/sigcontext.h" -#include "irq_user.h" -#include "ptrace_user.h" -#include "time_user.h" -#include "init.h" -#include "os.h" -#include "uml-config.h" -#include "choose-mode.h" -#include "mode.h" -#include "tempfile.h" -#ifdef UML_CONFIG_MODE_SKAS -#include "skas.h" -#include "skas_ptrace.h" -#include "registers.h" -#endif - -void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)) -{ - int flags = 0, pages; - - if(sig_stack != NULL){ - pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER); - set_sigstack(sig_stack, pages * page_size()); - flags = SA_ONSTACK; - } - if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1); -} - -void init_new_thread_signals(int altstack) -{ - int flags = altstack ? SA_ONSTACK : 0; - - set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags, - SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); - set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags, - SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); - set_handler(SIGFPE, (__sighandler_t) sig_handler, flags, - SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); - set_handler(SIGILL, (__sighandler_t) sig_handler, flags, - SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); - set_handler(SIGBUS, (__sighandler_t) sig_handler, flags, - SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); - set_handler(SIGUSR2, (__sighandler_t) sig_handler, - flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); - signal(SIGHUP, SIG_IGN); - - init_irq_signals(altstack); -} - -struct tramp { - int (*tramp)(void *); - void *tramp_data; - unsigned long temp_stack; - int flags; - int pid; -}; - -/* See above for why sigkill is here */ - -int sigkill = SIGKILL; - -int outer_tramp(void *arg) -{ - struct tramp *t; - int sig = sigkill; - - t = arg; - t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2, - t->flags, t->tramp_data); - if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL); - kill(os_getpid(), sig); - _exit(0); -} - -int start_fork_tramp(void *thread_arg, unsigned long temp_stack, - int clone_flags, int (*tramp)(void *)) -{ - struct tramp arg; - unsigned long sp; - int new_pid, status, err; - - /* The trampoline will run on the temporary stack */ - sp = stack_sp(temp_stack); - - clone_flags |= CLONE_FILES | SIGCHLD; - - arg.tramp = tramp; - arg.tramp_data = thread_arg; - arg.temp_stack = temp_stack; - arg.flags = clone_flags; - - /* Start the process and wait for it to kill itself */ - new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg); - if(new_pid < 0) - return(new_pid); - - CATCH_EINTR(err = waitpid(new_pid, &status, 0)); - if(err < 0) - panic("Waiting for outer trampoline failed - errno = %d", - errno); - - if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL)) - panic("outer trampoline didn't exit with SIGKILL, " - "status = %d", status); - - return(arg.pid); -} - -static int ptrace_child(void *arg) -{ - int ret; - int pid = os_getpid(), ppid = getppid(); - int sc_result; - - if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){ - perror("ptrace"); - os_kill_process(pid, 0); - } - os_stop_process(pid); - - /*This syscall will be intercepted by the parent. Don't call more than - * once, please.*/ - sc_result = os_getpid(); - - if (sc_result == pid) - ret = 1; /*Nothing modified by the parent, we are running - normally.*/ - else if (sc_result == ppid) - ret = 0; /*Expected in check_ptrace and check_sysemu when they - succeed in modifying the stack frame*/ - else - ret = 2; /*Serious trouble! This could be caused by a bug in - host 2.6 SKAS3/2.6 patch before release -V6, together - with a bug in the UML code itself.*/ - _exit(ret); -} - -static int start_ptraced_child(void **stack_out) -{ - void *stack; - unsigned long sp; - int pid, n, status; - - stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - if(stack == MAP_FAILED) - panic("check_ptrace : mmap failed, errno = %d", errno); - sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); - pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL); - if(pid < 0) - panic("check_ptrace : clone failed, errno = %d", errno); - CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); - if(n < 0) - panic("check_ptrace : wait failed, errno = %d", errno); - if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) - panic("check_ptrace : expected SIGSTOP, got status = %d", - status); - - *stack_out = stack; - return(pid); -} - -/* When testing for SYSEMU support, if it is one of the broken versions, we must - * just avoid using sysemu, not panic, but only if SYSEMU features are broken. - * So only for SYSEMU features we test mustpanic, while normal host features - * must work anyway!*/ -static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic) -{ - int status, n, ret = 0; - - if(ptrace(PTRACE_CONT, pid, 0, 0) < 0) - panic("check_ptrace : ptrace failed, errno = %d", errno); - CATCH_EINTR(n = waitpid(pid, &status, 0)); - if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { - int exit_with = WEXITSTATUS(status); - if (exit_with == 2) - printk("check_ptrace : child exited with status 2. " - "Serious trouble happening! Try updating your " - "host skas patch!\nDisabling SYSEMU support."); - printk("check_ptrace : child exited with exitcode %d, while " - "expecting %d; status 0x%x", exit_with, - exitcode, status); - if (mustpanic) - panic("\n"); - else - printk("\n"); - ret = -1; - } - - if(munmap(stack, PAGE_SIZE) < 0) - panic("check_ptrace : munmap failed, errno = %d", errno); - return ret; -} - -static int force_sysemu_disabled = 0; - -int ptrace_faultinfo = 1; -int proc_mm = 1; - -static int __init skas0_cmd_param(char *str, int* add) -{ - ptrace_faultinfo = proc_mm = 0; - return 0; -} - -static int __init nosysemu_cmd_param(char *str, int* add) -{ - force_sysemu_disabled = 1; - return 0; -} - -__uml_setup("skas0", skas0_cmd_param, - "skas0\n" - " Disables SKAS3 usage, so that SKAS0 is used, unless you \n" - " specify mode=tt.\n\n"); - -__uml_setup("nosysemu", nosysemu_cmd_param, - "nosysemu\n" - " Turns off syscall emulation patch for ptrace (SYSEMU) on.\n" - " SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n" - " behaviour of ptrace() and helps reducing host context switch rate.\n" - " To make it working, you need a kernel patch for your host, too.\n" - " See http://perso.wanadoo.fr/laurent.vivier/UML/ for further information.\n\n"); - -static void __init check_sysemu(void) -{ - void *stack; - int pid, syscall, n, status, count=0; - - printk("Checking syscall emulation patch for ptrace..."); - sysemu_supported = 0; - pid = start_ptraced_child(&stack); - - if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) - goto fail; - - CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); - if (n < 0) - panic("check_sysemu : wait failed, errno = %d", errno); - if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) - panic("check_sysemu : expected SIGTRAP, " - "got status = %d", status); - - n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, - os_getpid()); - if(n < 0) - panic("check_sysemu : failed to modify system " - "call return, errno = %d", errno); - - if (stop_ptraced_child(pid, stack, 0, 0) < 0) - goto fail_stopped; - - sysemu_supported = 1; - printk("OK\n"); - set_using_sysemu(!force_sysemu_disabled); - - printk("Checking advanced syscall emulation patch for ptrace..."); - pid = start_ptraced_child(&stack); - while(1){ - count++; - if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) - goto fail; - CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); - if(n < 0) - panic("check_ptrace : wait failed, errno = %d", errno); - if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) - panic("check_ptrace : expected (SIGTRAP|SYSCALL_TRAP), " - "got status = %d", status); - - syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET, - 0); - if(syscall == __NR_getpid){ - if (!count) - panic("check_ptrace : SYSEMU_SINGLESTEP doesn't singlestep"); - n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, - os_getpid()); - if(n < 0) - panic("check_sysemu : failed to modify system " - "call return, errno = %d", errno); - break; - } - } - if (stop_ptraced_child(pid, stack, 0, 0) < 0) - goto fail_stopped; - - sysemu_supported = 2; - printk("OK\n"); - - if ( !force_sysemu_disabled ) - set_using_sysemu(sysemu_supported); - return; - -fail: - stop_ptraced_child(pid, stack, 1, 0); -fail_stopped: - printk("missing\n"); -} - -void __init check_ptrace(void) -{ - void *stack; - int pid, syscall, n, status; - - printk("Checking that ptrace can change system call numbers..."); - pid = start_ptraced_child(&stack); - - if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) - panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno); - - while(1){ - if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) - panic("check_ptrace : ptrace failed, errno = %d", - errno); - CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); - if(n < 0) - panic("check_ptrace : wait failed, errno = %d", errno); - if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP + 0x80)) - panic("check_ptrace : expected SIGTRAP + 0x80, " - "got status = %d", status); - - syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET, - 0); - if(syscall == __NR_getpid){ - n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, - __NR_getppid); - if(n < 0) - panic("check_ptrace : failed to modify system " - "call, errno = %d", errno); - break; - } - } - stop_ptraced_child(pid, stack, 0, 1); - printk("OK\n"); - check_sysemu(); -} - -int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) -{ - sigjmp_buf buf; - int n; - - *jmp_ptr = &buf; - n = sigsetjmp(buf, 1); - if(n != 0) - return(n); - (*fn)(arg); - return(0); -} - -void forward_pending_sigio(int target) -{ - sigset_t sigs; - - if(sigpending(&sigs)) - panic("forward_pending_sigio : sigpending failed"); - if(sigismember(&sigs, SIGIO)) - kill(target, SIGIO); -} - -extern void *__syscall_stub_start, __syscall_stub_end; - -#ifdef UML_CONFIG_MODE_SKAS - -static inline void check_skas3_ptrace_support(void) -{ - struct ptrace_faultinfo fi; - void *stack; - int pid, n; - - printf("Checking for the skas3 patch in the host..."); - pid = start_ptraced_child(&stack); - - n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); - if (n < 0) { - ptrace_faultinfo = 0; - if(errno == EIO) - printf("not found\n"); - else { - perror("not found"); - } - } - else { - if (!ptrace_faultinfo) - printf("found but disabled on command line\n"); - else - printf("found\n"); - } - - init_registers(pid); - stop_ptraced_child(pid, stack, 1, 1); -} - -int can_do_skas(void) -{ - printf("Checking for /proc/mm..."); - if (os_access("/proc/mm", OS_ACC_W_OK) < 0) { - proc_mm = 0; - printf("not found\n"); - } else { - if (!proc_mm) - printf("found but disabled on command line\n"); - else - printf("found\n"); - } - - check_skas3_ptrace_support(); - return 1; -} -#else -int can_do_skas(void) -{ - return(0); -} -#endif diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index b781b6f94283..09f6f7ce4695 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -333,6 +333,7 @@ int linux_main(int argc, char **argv) if(have_root == 0) add_arg(DEFAULT_COMMAND_LINE); + os_early_checks(); mode_tt = force_tt ? 1 : !can_do_skas(); #ifndef CONFIG_MODE_TT if (mode_tt) { @@ -470,7 +471,6 @@ void __init setup_arch(char **cmdline_p) void __init check_bugs(void) { arch_check_bugs(); - check_ptrace(); check_sigio(); check_devanon(); } diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile index 351d96934679..d3c1560e3ed8 100644 --- a/arch/um/os-Linux/Makefile +++ b/arch/um/os-Linux/Makefile @@ -3,10 +3,11 @@ # Licensed under the GPL # -obj-y = aio.o elf_aux.o file.o process.o signal.o time.o tty.o user_syms.o \ - drivers/ sys-$(SUBARCH)/ +obj-y = aio.o elf_aux.o file.o process.o signal.o start_up.o time.o tt.o \ + tty.o user_syms.o drivers/ sys-$(SUBARCH)/ -USER_OBJS := aio.o elf_aux.o file.o process.o signal.o time.o tty.o +USER_OBJS := aio.o elf_aux.o file.o process.o signal.o start_up.o time.o tt.o \ + tty.o CFLAGS_user_syms.o += -DSUBARCH_$(SUBARCH) diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c index 1e126bfd31a7..d32413e4b4ce 100644 --- a/arch/um/os-Linux/process.c +++ b/arch/um/os-Linux/process.c @@ -3,10 +3,10 @@ * Licensed under the GPL */ -#include #include #include #include +#include #include #include #include @@ -14,6 +14,10 @@ #include "os.h" #include "user.h" #include "user_util.h" +#include "signal_user.h" +#include "process.h" +#include "irq_user.h" +#include "kern_util.h" #define ARBITRARY_ADDR -1 #define FAILURE_PID -1 @@ -114,8 +118,10 @@ void os_usr1_process(int pid) kill(pid, SIGUSR1); } -/*Don't use the glibc version, which caches the result in TLS. It misses some - * syscalls, and also breaks with clone(), which does not unshare the TLS.*/ +/* Don't use the glibc version, which caches the result in TLS. It misses some + * syscalls, and also breaks with clone(), which does not unshare the TLS. + */ + inline _syscall0(pid_t, getpid) int os_getpid(void) @@ -164,6 +170,52 @@ int os_unmap_memory(void *addr, int len) return(0); } +void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int)) +{ + int flags = 0, pages; + + if(sig_stack != NULL){ + pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER); + set_sigstack(sig_stack, pages * page_size()); + flags = SA_ONSTACK; + } + if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1); +} + +void init_new_thread_signals(int altstack) +{ + int flags = altstack ? SA_ONSTACK : 0; + + set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + set_handler(SIGFPE, (__sighandler_t) sig_handler, flags, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + set_handler(SIGILL, (__sighandler_t) sig_handler, flags, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + set_handler(SIGBUS, (__sighandler_t) sig_handler, flags, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + set_handler(SIGUSR2, (__sighandler_t) sig_handler, + flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + signal(SIGHUP, SIG_IGN); + + init_irq_signals(altstack); +} + +int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr) +{ + sigjmp_buf buf; + int n; + + *jmp_ptr = &buf; + n = sigsetjmp(buf, 1); + if(n != 0) + return(n); + (*fn)(arg); + return(0); +} + /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c new file mode 100644 index 000000000000..a3eab25f3791 --- /dev/null +++ b/arch/um/os-Linux/start_up.c @@ -0,0 +1,329 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "user_util.h" +#include "kern_util.h" +#include "user.h" +#include "signal_kern.h" +#include "signal_user.h" +#include "sysdep/ptrace.h" +#include "sysdep/sigcontext.h" +#include "irq_user.h" +#include "ptrace_user.h" +#include "time_user.h" +#include "init.h" +#include "os.h" +#include "uml-config.h" +#include "choose-mode.h" +#include "mode.h" +#include "tempfile.h" +#ifdef UML_CONFIG_MODE_SKAS +#include "skas.h" +#include "skas_ptrace.h" +#include "registers.h" +#endif + +static int ptrace_child(void *arg) +{ + int ret; + int pid = os_getpid(), ppid = getppid(); + int sc_result; + + if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){ + perror("ptrace"); + os_kill_process(pid, 0); + } + os_stop_process(pid); + + /*This syscall will be intercepted by the parent. Don't call more than + * once, please.*/ + sc_result = os_getpid(); + + if (sc_result == pid) + ret = 1; /*Nothing modified by the parent, we are running + normally.*/ + else if (sc_result == ppid) + ret = 0; /*Expected in check_ptrace and check_sysemu when they + succeed in modifying the stack frame*/ + else + ret = 2; /*Serious trouble! This could be caused by a bug in + host 2.6 SKAS3/2.6 patch before release -V6, together + with a bug in the UML code itself.*/ + _exit(ret); +} + +static int start_ptraced_child(void **stack_out) +{ + void *stack; + unsigned long sp; + int pid, n, status; + + stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if(stack == MAP_FAILED) + panic("check_ptrace : mmap failed, errno = %d", errno); + sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); + pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL); + if(pid < 0) + panic("start_ptraced_child : clone failed, errno = %d", errno); + CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); + if(n < 0) + panic("check_ptrace : clone failed, errno = %d", errno); + if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) + panic("check_ptrace : expected SIGSTOP, got status = %d", + status); + + *stack_out = stack; + return(pid); +} + +/* When testing for SYSEMU support, if it is one of the broken versions, we + * must just avoid using sysemu, not panic, but only if SYSEMU features are + * broken. + * So only for SYSEMU features we test mustpanic, while normal host features + * must work anyway! + */ +static int stop_ptraced_child(int pid, void *stack, int exitcode, + int mustpanic) +{ + int status, n, ret = 0; + + if(ptrace(PTRACE_CONT, pid, 0, 0) < 0) + panic("check_ptrace : ptrace failed, errno = %d", errno); + CATCH_EINTR(n = waitpid(pid, &status, 0)); + if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { + int exit_with = WEXITSTATUS(status); + if (exit_with == 2) + printk("check_ptrace : child exited with status 2. " + "Serious trouble happening! Try updating your " + "host skas patch!\nDisabling SYSEMU support."); + printk("check_ptrace : child exited with exitcode %d, while " + "expecting %d; status 0x%x", exit_with, + exitcode, status); + if (mustpanic) + panic("\n"); + else + printk("\n"); + ret = -1; + } + + if(munmap(stack, PAGE_SIZE) < 0) + panic("check_ptrace : munmap failed, errno = %d", errno); + return ret; +} + +int ptrace_faultinfo = 1; +int proc_mm = 1; + +static int __init skas0_cmd_param(char *str, int* add) +{ + ptrace_faultinfo = proc_mm = 0; + return 0; +} + +__uml_setup("skas0", skas0_cmd_param, + "skas0\n" + " Disables SKAS3 usage, so that SKAS0 is used, unless \n" + " you specify mode=tt.\n\n"); + +static int force_sysemu_disabled = 0; + +static int __init nosysemu_cmd_param(char *str, int* add) +{ + force_sysemu_disabled = 1; + return 0; +} + +__uml_setup("nosysemu", nosysemu_cmd_param, +"nosysemu\n" +" Turns off syscall emulation patch for ptrace (SYSEMU) on.\n" +" SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n" +" behaviour of ptrace() and helps reducing host context switch rate.\n" +" To make it working, you need a kernel patch for your host, too.\n" +" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n" +" information.\n\n"); + +static void __init check_sysemu(void) +{ + void *stack; + int pid, syscall, n, status, count=0; + + printk("Checking syscall emulation patch for ptrace..."); + sysemu_supported = 0; + pid = start_ptraced_child(&stack); + + if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) + goto fail; + + CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); + if (n < 0) + panic("check_sysemu : wait failed, errno = %d", errno); + if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) + panic("check_sysemu : expected SIGTRAP, " + "got status = %d", status); + + n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, + os_getpid()); + if(n < 0) + panic("check_sysemu : failed to modify system " + "call return, errno = %d", errno); + + if (stop_ptraced_child(pid, stack, 0, 0) < 0) + goto fail_stopped; + + sysemu_supported = 1; + printk("OK\n"); + set_using_sysemu(!force_sysemu_disabled); + + printk("Checking advanced syscall emulation patch for ptrace..."); + pid = start_ptraced_child(&stack); + while(1){ + count++; + if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) + goto fail; + CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); + if(n < 0) + panic("check_ptrace : wait failed, errno = %d", errno); + if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) + panic("check_ptrace : expected (SIGTRAP|SYSCALL_TRAP), " + "got status = %d", status); + + syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET, + 0); + if(syscall == __NR_getpid){ + if (!count) + panic("check_ptrace : SYSEMU_SINGLESTEP doesn't singlestep"); + n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, + os_getpid()); + if(n < 0) + panic("check_sysemu : failed to modify system " + "call return, errno = %d", errno); + break; + } + } + if (stop_ptraced_child(pid, stack, 0, 0) < 0) + goto fail_stopped; + + sysemu_supported = 2; + printk("OK\n"); + + if ( !force_sysemu_disabled ) + set_using_sysemu(sysemu_supported); + return; + +fail: + stop_ptraced_child(pid, stack, 1, 0); +fail_stopped: + printk("missing\n"); +} + +static void __init check_ptrace(void) +{ + void *stack; + int pid, syscall, n, status; + + printk("Checking that ptrace can change system call numbers..."); + pid = start_ptraced_child(&stack); + + if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) + panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno); + + while(1){ + if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) + panic("check_ptrace : ptrace failed, errno = %d", + errno); + CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); + if(n < 0) + panic("check_ptrace : wait failed, errno = %d", errno); + if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP + 0x80)) + panic("check_ptrace : expected SIGTRAP + 0x80, " + "got status = %d", status); + + syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET, + 0); + if(syscall == __NR_getpid){ + n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, + __NR_getppid); + if(n < 0) + panic("check_ptrace : failed to modify system " + "call, errno = %d", errno); + break; + } + } + stop_ptraced_child(pid, stack, 0, 1); + printk("OK\n"); + check_sysemu(); +} + +void os_early_checks(void) +{ + check_ptrace(); +} + +#ifdef UML_CONFIG_MODE_SKAS +static inline void check_skas3_ptrace_support(void) +{ + struct ptrace_faultinfo fi; + void *stack; + int pid, n; + + printf("Checking for the skas3 patch in the host..."); + pid = start_ptraced_child(&stack); + + n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); + if (n < 0) { + ptrace_faultinfo = 0; + if(errno == EIO) + printf("not found\n"); + else + perror("not found"); + } + else { + if (!ptrace_faultinfo) + printf("found but disabled on command line\n"); + else + printf("found\n"); + } + + init_registers(pid); + stop_ptraced_child(pid, stack, 1, 1); +} + +int can_do_skas(void) +{ + printf("Checking for /proc/mm..."); + if (os_access("/proc/mm", OS_ACC_W_OK) < 0) { + proc_mm = 0; + printf("not found\n"); + } + else { + if (!proc_mm) + printf("found but disabled on command line\n"); + else + printf("found\n"); + } + + check_skas3_ptrace_support(); + return 1; +} +#else +int can_do_skas(void) +{ + return(0); +} +#endif diff --git a/arch/um/os-Linux/tt.c b/arch/um/os-Linux/tt.c new file mode 100644 index 000000000000..5b047ab8416a --- /dev/null +++ b/arch/um/os-Linux/tt.c @@ -0,0 +1,113 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "user_util.h" +#include "kern_util.h" +#include "user.h" +#include "signal_kern.h" +#include "signal_user.h" +#include "sysdep/ptrace.h" +#include "sysdep/sigcontext.h" +#include "irq_user.h" +#include "ptrace_user.h" +#include "time_user.h" +#include "init.h" +#include "os.h" +#include "uml-config.h" +#include "choose-mode.h" +#include "mode.h" +#include "tempfile.h" + +/* + *------------------------- + * only for tt mode (will be deleted in future...) + *------------------------- + */ + +struct tramp { + int (*tramp)(void *); + void *tramp_data; + unsigned long temp_stack; + int flags; + int pid; +}; + +/* See above for why sigkill is here */ + +int sigkill = SIGKILL; + +int outer_tramp(void *arg) +{ + struct tramp *t; + int sig = sigkill; + + t = arg; + t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2, + t->flags, t->tramp_data); + if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL); + kill(os_getpid(), sig); + _exit(0); +} + +int start_fork_tramp(void *thread_arg, unsigned long temp_stack, + int clone_flags, int (*tramp)(void *)) +{ + struct tramp arg; + unsigned long sp; + int new_pid, status, err; + + /* The trampoline will run on the temporary stack */ + sp = stack_sp(temp_stack); + + clone_flags |= CLONE_FILES | SIGCHLD; + + arg.tramp = tramp; + arg.tramp_data = thread_arg; + arg.temp_stack = temp_stack; + arg.flags = clone_flags; + + /* Start the process and wait for it to kill itself */ + new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg); + if(new_pid < 0) + return(new_pid); + + CATCH_EINTR(err = waitpid(new_pid, &status, 0)); + if(err < 0) + panic("Waiting for outer trampoline failed - errno = %d", + errno); + + if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL)) + panic("outer trampoline didn't exit with SIGKILL, " + "status = %d", status); + + return(arg.pid); +} + +void forward_pending_sigio(int target) +{ + sigset_t sigs; + + if(sigpending(&sigs)) + panic("forward_pending_sigio : sigpending failed"); + if(sigismember(&sigs, SIGIO)) + kill(target, SIGIO); +} + -- cgit v1.2.1