fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / arch / arm / mm / fault.c
index e25b4fd..0e78479 100644 (file)
@@ -8,7 +8,6 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/signal.h>
 #include <linux/ptrace.h>
@@ -132,10 +131,11 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr,
        force_sig_info(sig, &si, tsk);
 }
 
-void
-do_bad_area(struct task_struct *tsk, struct mm_struct *mm, unsigned long addr,
-           unsigned int fsr, struct pt_regs *regs)
+void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
+       struct task_struct *tsk = current;
+       struct mm_struct *mm = tsk->active_mm;
+
        /*
         * If we are in kernel mode at this point, we
         * have no context to handle this fault with.
@@ -171,7 +171,7 @@ good_area:
        if (fsr & (1 << 11)) /* write? */
                mask = VM_WRITE;
        else
-               mask = VM_READ|VM_EXEC;
+               mask = VM_READ|VM_EXEC|VM_WRITE;
 
        fault = VM_FAULT_BADACCESS;
        if (!(vma->vm_flags & mask))
@@ -198,7 +198,7 @@ survive:
                return fault;
        }
 
-       if (tsk->pid != 1)
+       if (!is_init(tsk))
                goto out;
 
        /*
@@ -230,17 +230,27 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
         * If we're in an interrupt or have no user
         * context, we must not take the fault..
         */
-       if (in_interrupt() || !mm)
+       if (in_atomic() || !mm)
                goto no_context;
 
-       down_read(&mm->mmap_sem);
+       /*
+        * As per x86, we may deadlock here.  However, since the kernel only
+        * validly references user space from well defined areas of the code,
+        * we can bug out early if this is from code which shouldn't.
+        */
+       if (!down_read_trylock(&mm->mmap_sem)) {
+               if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc))
+                       goto no_context;
+               down_read(&mm->mmap_sem);
+       }
+
        fault = __do_page_fault(mm, addr, fsr, tsk);
        up_read(&mm->mmap_sem);
 
        /*
-        * Handle the "normal" case first
+        * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
         */
-       if (fault > 0)
+       if (fault >= VM_FAULT_MINOR)
                return 0;
 
        /*
@@ -257,11 +267,12 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
                 * happened to us that made us unable to handle
                 * the page fault gracefully.
                 */
-               printk("VM: killing process %s\n", tsk->comm);
+               printk("VM: killing process %s(%d:#%u)\n",
+                       tsk->comm, tsk->pid, tsk->xid);
                do_exit(SIGKILL);
                return 0;
 
-       case 0:
+       case VM_FAULT_SIGBUS:
                /*
                 * We had some memory, but were unable to
                 * successfully fix up this page fault.
@@ -310,7 +321,6 @@ static int
 do_translation_fault(unsigned long addr, unsigned int fsr,
                     struct pt_regs *regs)
 {
-       struct task_struct *tsk;
        unsigned int index;
        pgd_t *pgd, *pgd_k;
        pmd_t *pmd, *pmd_k;
@@ -342,9 +352,7 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
        return 0;
 
 bad_area:
-       tsk = current;
-
-       do_bad_area(tsk, tsk->active_mm, addr, fsr, regs);
+       do_bad_area(addr, fsr, regs);
        return 0;
 }
 
@@ -355,8 +363,7 @@ bad_area:
 static int
 do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
-       struct task_struct *tsk = current;
-       do_bad_area(tsk, tsk->active_mm, addr, fsr, regs);
+       do_bad_area(addr, fsr, regs);
        return 0;
 }
 
@@ -372,49 +379,50 @@ do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 static struct fsr_info {
        int     (*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs);
        int     sig;
+       int     code;
        const char *name;
 } fsr_info[] = {
        /*
         * The following are the standard ARMv3 and ARMv4 aborts.  ARMv5
         * defines these to be "precise" aborts.
         */
-       { do_bad,               SIGSEGV, "vector exception"                },
-       { do_bad,               SIGILL,  "alignment exception"             },
-       { do_bad,               SIGKILL, "terminal exception"              },
-       { do_bad,               SIGILL,  "alignment exception"             },
-       { do_bad,               SIGBUS,  "external abort on linefetch"     },
-       { do_translation_fault, SIGSEGV, "section translation fault"       },
-       { do_bad,               SIGBUS,  "external abort on linefetch"     },
-       { do_page_fault,        SIGSEGV, "page translation fault"          },
-       { do_bad,               SIGBUS,  "external abort on non-linefetch" },
-       { do_bad,               SIGSEGV, "section domain fault"            },
-       { do_bad,               SIGBUS,  "external abort on non-linefetch" },
-       { do_bad,               SIGSEGV, "page domain fault"               },
-       { do_bad,               SIGBUS,  "external abort on translation"   },
-       { do_sect_fault,        SIGSEGV, "section permission fault"        },
-       { do_bad,               SIGBUS,  "external abort on translation"   },
-       { do_page_fault,        SIGSEGV, "page permission fault"           },
+       { do_bad,               SIGSEGV, 0,             "vector exception"                 },
+       { do_bad,               SIGILL,  BUS_ADRALN,    "alignment exception"              },
+       { do_bad,               SIGKILL, 0,             "terminal exception"               },
+       { do_bad,               SIGILL,  BUS_ADRALN,    "alignment exception"              },
+       { do_bad,               SIGBUS,  0,             "external abort on linefetch"      },
+       { do_translation_fault, SIGSEGV, SEGV_MAPERR,   "section translation fault"        },
+       { do_bad,               SIGBUS,  0,             "external abort on linefetch"      },
+       { do_page_fault,        SIGSEGV, SEGV_MAPERR,   "page translation fault"           },
+       { do_bad,               SIGBUS,  0,             "external abort on non-linefetch"  },
+       { do_bad,               SIGSEGV, SEGV_ACCERR,   "section domain fault"             },
+       { do_bad,               SIGBUS,  0,             "external abort on non-linefetch"  },
+       { do_bad,               SIGSEGV, SEGV_ACCERR,   "page domain fault"                },
+       { do_bad,               SIGBUS,  0,             "external abort on translation"    },
+       { do_sect_fault,        SIGSEGV, SEGV_ACCERR,   "section permission fault"         },
+       { do_bad,               SIGBUS,  0,             "external abort on translation"    },
+       { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "page permission fault"            },
        /*
         * The following are "imprecise" aborts, which are signalled by bit
         * 10 of the FSR, and may not be recoverable.  These are only
         * supported if the CPU abort handler supports bit 10.
         */
-       { do_bad,               SIGBUS,  "unknown 16"                      },
-       { do_bad,               SIGBUS,  "unknown 17"                      },
-       { do_bad,               SIGBUS,  "unknown 18"                      },
-       { do_bad,               SIGBUS,  "unknown 19"                      },
-       { do_bad,               SIGBUS,  "lock abort"                      }, /* xscale */
-       { do_bad,               SIGBUS,  "unknown 21"                      },
-       { do_bad,               SIGBUS,  "imprecise external abort"        }, /* xscale */
-       { do_bad,               SIGBUS,  "unknown 23"                      },
-       { do_bad,               SIGBUS,  "dcache parity error"             }, /* xscale */
-       { do_bad,               SIGBUS,  "unknown 25"                      },
-       { do_bad,               SIGBUS,  "unknown 26"                      },
-       { do_bad,               SIGBUS,  "unknown 27"                      },
-       { do_bad,               SIGBUS,  "unknown 28"                      },
-       { do_bad,               SIGBUS,  "unknown 29"                      },
-       { do_bad,               SIGBUS,  "unknown 30"                      },
-       { do_bad,               SIGBUS,  "unknown 31"                      }
+       { do_bad,               SIGBUS,  0,             "unknown 16"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 17"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 18"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 19"                       },
+       { do_bad,               SIGBUS,  0,             "lock abort"                       }, /* xscale */
+       { do_bad,               SIGBUS,  0,             "unknown 21"                       },
+       { do_bad,               SIGBUS,  BUS_OBJERR,    "imprecise external abort"         }, /* xscale */
+       { do_bad,               SIGBUS,  0,             "unknown 23"                       },
+       { do_bad,               SIGBUS,  0,             "dcache parity error"              }, /* xscale */
+       { do_bad,               SIGBUS,  0,             "unknown 25"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 26"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 27"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 28"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 29"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 30"                       },
+       { do_bad,               SIGBUS,  0,             "unknown 31"                       }
 };
 
 void __init
@@ -435,15 +443,19 @@ asmlinkage void
 do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
        const struct fsr_info *inf = fsr_info + (fsr & 15) + ((fsr & (1 << 10)) >> 6);
+       struct siginfo info;
 
        if (!inf->fn(addr, fsr, regs))
                return;
 
        printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n",
                inf->name, fsr, addr);
-       force_sig(inf->sig, current);
-       show_pte(current->mm, addr);
-       die_if_kernel("Oops", regs, 0);
+
+       info.si_signo = inf->sig;
+       info.si_errno = 0;
+       info.si_code  = inf->code;
+       info.si_addr  = (void __user *)addr;
+       notify_die("", regs, &info, fsr, 0);
 }
 
 asmlinkage void