mm: invoke oom-killer from page fault

[pandora-kernel.git] / arch / um / kernel / trap.c

diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index bd06055..7384d8a 100644 (file)
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -13,6 +13,7 @@
 #include "as-layout.h"
 #include "kern_util.h"
 #include "os.h"
+#include "skas.h"
 #include "sysdep/sigcontext.h"
 
 /*
@@ -63,11 +64,10 @@ good_area:
 
        do {
                int fault;
-survive:
+
                fault = handle_mm_fault(mm, vma, address, is_write);
                if (unlikely(fault & VM_FAULT_ERROR)) {
                        if (fault & VM_FAULT_OOM) {
-                               err = -ENOMEM;
                                goto out_of_memory;
                        } else if (fault & VM_FAULT_SIGBUS) {
                                err = -EACCES;
@@ -103,18 +103,14 @@ out:
 out_nosemaphore:
        return err;
 
-/*
- * We ran out of memory, or some other thing happened to us that made
- * us unable to handle the page fault gracefully.
- */
 out_of_memory:
-       if (is_init(current)) {
-               up_read(&mm->mmap_sem);
-               yield();
-               down_read(&mm->mmap_sem);
-               goto survive;
-       }
-       goto out;
+       /*
+        * We ran out of memory, call the OOM killer, and return the userspace
+        * (which will retry the fault, or kill us if we got oom-killed).
+        */
+       up_read(&mm->mmap_sem);
+       pagefault_out_of_memory();
+       return 0;
 }
 
 static void bad_segv(struct faultinfo fi, unsigned long ip)
@@ -128,7 +124,19 @@ static void bad_segv(struct faultinfo fi, unsigned long ip)
        force_sig_info(SIGSEGV, &si, current);
 }
 
-static void segv_handler(int sig, struct uml_pt_regs *regs)
+void fatal_sigsegv(void)
+{
+       force_sigsegv(SIGSEGV, current);
+       do_signal();
+       /*
+        * This is to tell gcc that we're not returning - do_signal
+        * can, in general, return, but in this case, it's not, since
+        * we just got a fatal SIGSEGV queued.
+        */
+       os_dump_core();
+}
+
+void segv_handler(int sig, struct uml_pt_regs *regs)
 {
        struct faultinfo * fi = UPT_FAULTINFO(regs);
 
@@ -201,9 +209,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
                si.si_addr = (void __user *)address;
                current->thread.arch.faultinfo = fi;
                force_sig_info(SIGBUS, &si, current);
-       } else if (err == -ENOMEM) {
-               printk(KERN_INFO "VM: killing process %s\n", current->comm);
-               do_exit(SIGKILL);
        } else {
                BUG_ON(err != -EFAULT);
                si.si_signo = SIGSEGV;
@@ -216,9 +221,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 void relay_signal(int sig, struct uml_pt_regs *regs)
 {
-       if (arch_handle_signal(sig, regs))
-               return;
-
        if (!UPT_IS_USER(regs)) {
                if (sig == SIGBUS)
                        printk(KERN_ERR "Bus error - the host /dev/shm or /tmp "
@@ -226,31 +228,24 @@ void relay_signal(int sig, struct uml_pt_regs *regs)
                panic("Kernel mode signal %d", sig);
        }
 
+       arch_examine_signal(sig, regs);
+
        current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
        force_sig(sig, current);
 }
 
-static void bus_handler(int sig, struct uml_pt_regs *regs)
+void bus_handler(int sig, struct uml_pt_regs *regs)
 {
        if (current->thread.fault_catcher != NULL)
                UML_LONGJMP(current->thread.fault_catcher, 1);
        else relay_signal(sig, regs);
 }
 
-static void winch(int sig, struct uml_pt_regs *regs)
+void winch(int sig, struct uml_pt_regs *regs)
 {
        do_IRQ(WINCH_IRQ, regs);
 }
 
-const struct kern_handlers handlinfo_kern = {
-       .relay_signal = relay_signal,
-       .winch = winch,
-       .bus_handler = bus_handler,
-       .page_fault = segv_handler,
-       .sigio_handler = sigio_handler,
-       .timer_handler = timer_handler
-};
-
 void trap_init(void)
 {
 }