2005-09-01 22:53:55

by Jeff Dike

[permalink] [raw]
Subject: [PATCH 7/12] UML - Move libc-dependent startup and signal code

From: Gennady Sharapov <[email protected]>

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 <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>

Index: test/arch/um/include/os.h
===================================================================
--- test.orig/arch/um/include/os.h 2005-06-17 15:48:29.000000000 -0400
+++ test/arch/um/include/os.h 2005-09-01 16:09:41.000000000 -0400
@@ -153,6 +153,11 @@
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_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 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

/*
Index: test/arch/um/include/user_util.h
===================================================================
--- test.orig/arch/um/include/user_util.h 2005-06-17 15:48:29.000000000 -0400
+++ test/arch/um/include/user_util.h 2005-09-01 16:09:41.000000000 -0400
@@ -54,8 +54,6 @@
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 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 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);
Index: test/arch/um/kernel/Makefile
===================================================================
--- test.orig/arch/um/kernel/Makefile 2005-09-01 16:04:19.000000000 -0400
+++ test/arch/um/kernel/Makefile 2005-09-01 16:09:41.000000000 -0400
@@ -8,11 +8,10 @@

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 @@

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

Index: test/arch/um/kernel/process.c
===================================================================
--- test.orig/arch/um/kernel/process.c 2005-09-01 16:02:46.000000000 -0400
+++ test/arch/um/kernel/process.c 2005-09-01 07:45:10.520901648 -0400
@@ -1,439 +0,0 @@
-/*
- * Copyright (C) 2000, 2001, 2002 Jeff Dike ([email protected])
- * Licensed under the GPL
- */
-
-#include <stdio.h>
-#include <unistd.h>
-#include <signal.h>
-#include <sched.h>
-#include <errno.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <setjmp.h>
-#include <sys/time.h>
-#include <sys/wait.h>
-#include <sys/mman.h>
-#include <asm/unistd.h>
-#include <asm/page.h>
-#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
Index: test/arch/um/kernel/um_arch.c
===================================================================
--- test.orig/arch/um/kernel/um_arch.c 2005-09-01 16:03:16.000000000 -0400
+++ test/arch/um/kernel/um_arch.c 2005-09-01 16:09:41.000000000 -0400
@@ -333,6 +333,7 @@
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 check_bugs(void)
{
arch_check_bugs();
- check_ptrace();
check_sigio();
check_devanon();
}
Index: test/arch/um/os-Linux/Makefile
===================================================================
--- test.orig/arch/um/os-Linux/Makefile 2005-09-01 16:04:47.000000000 -0400
+++ test/arch/um/os-Linux/Makefile 2005-09-01 16:09:41.000000000 -0400
@@ -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)

Index: test/arch/um/os-Linux/process.c
===================================================================
--- test.orig/arch/um/os-Linux/process.c 2005-06-17 15:48:29.000000000 -0400
+++ test/arch/um/os-Linux/process.c 2005-09-01 16:09:41.000000000 -0400
@@ -3,10 +3,10 @@
* Licensed under the GPL
*/

-#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <signal.h>
+#include <setjmp.h>
#include <linux/unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>
@@ -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 @@
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 @@
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
Index: test/arch/um/os-Linux/start_up.c
===================================================================
--- test.orig/arch/um/os-Linux/start_up.c 2005-09-01 07:45:10.520901648 -0400
+++ test/arch/um/os-Linux/start_up.c 2005-09-01 16:32:52.000000000 -0400
@@ -0,0 +1,329 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike ([email protected])
+ * Licensed under the GPL
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sched.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <setjmp.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <asm/unistd.h>
+#include <asm/page.h>
+#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
Index: test/arch/um/os-Linux/tt.c
===================================================================
--- test.orig/arch/um/os-Linux/tt.c 2005-09-01 07:45:10.520901648 -0400
+++ test/arch/um/os-Linux/tt.c 2005-09-01 16:09:41.000000000 -0400
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike ([email protected])
+ * Licensed under the GPL
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sched.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <setjmp.h>
+#include <sys/time.h>
+#include <sys/ptrace.h>
+#include <linux/ptrace.h>
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <asm/ptrace.h>
+#include <asm/unistd.h>
+#include <asm/page.h>
+#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);
+}
+