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 0564422c155f2601d8329eabe3175bc1c4166e52..5c088a55396ce3a0b5fbe97f40499cdd9362c7d6 100644 (file)
@@ -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, &regs->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)