Merge branch 'drm-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...
[linux-drm-fsl-dcu.git] / arch / um / os-Linux / skas / process.c
index 1f39f2bf7ce9af0b01a5755ca82fc83d55902512..5c088a55396ce3a0b5fbe97f40499cdd9362c7d6 100644 (file)
@@ -34,6 +34,7 @@
 #include "process.h"
 #include "longjmp.h"
 #include "kern_constants.h"
+#include "as-layout.h"
 
 int is_skas_winch(int pid, int fd, void *data)
 {
@@ -60,37 +61,42 @@ static int ptrace_dump_regs(int pid)
         return 0;
 }
 
-void wait_stub_done(int pid, int sig, char * fname)
+/*
+ * 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;
 
-       do {
-               if ( sig != -1 ) {
-                       err = ptrace(PTRACE_CONT, pid, 0, sig);
-                       if(err)
-                               panic("%s : continue failed, errno = %d\n",
-                                     fname, errno);
-               }
-               sig = 0;
-
+       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)){
-               err = ptrace_dump_regs(pid);
+               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)
-                       printk("Failed to get registers from stub, "
-                              "errno = %d\n", -err);
-               panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
-                     "pid = %d, n = %d, errno = %d, status = 0x%x\n",
-                     fname, pid, n, errno, status);
+                       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);
@@ -112,7 +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.
@@ -304,10 +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, &regs->skas.faultinfo);
+                                       (*sig_info[SIGSEGV])(SIGSEGV, regs);
+                               }
                                else handle_segv(pid, regs);
                                break;
                        case SIGTRAP + 0x80:
@@ -322,11 +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();
@@ -338,11 +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;
@@ -357,23 +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);
@@ -384,7 +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)
@@ -394,7 +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);