Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / arch / arm / mm / fault.c
index e25b4fd..4a884ba 100644 (file)
@@ -233,14 +233,24 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
        if (in_interrupt() || !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;
 
        /*
@@ -261,7 +271,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
                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.
@@ -372,49 +382,50 @@ 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 +446,19 @@ 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