[PATCH] uml: S390 preparation, abstract host page fault data

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

diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
index 47e766e..54e2ec3 100644 (file)
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -133,12 +133,19 @@ static int check_remapped_addr(unsigned long address, int is_write)
        return(0);
 }
 
-unsigned long segv(unsigned long address, unsigned long ip, int is_write, 
-                  int is_user, void *sc)
+/*
+ * We give a *copy* of the faultinfo in the regs to segv.
+ * This must be done, since nesting SEGVs could overwrite
+ * the info in the regs. A pointer to the info then would
+ * give us bad data!
+ */
+unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
 {
        struct siginfo si;
        void *catcher;
        int err;
+        int is_write = FAULT_WRITE(fi);
+        unsigned long address = FAULT_ADDRESS(fi);
 
         if(!is_user && (address >= start_vm) && (address < end_vm)){
                 flush_tlb_kernel_vm();
@@ -159,7 +166,7 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
        } 
        else if(current->thread.fault_addr != NULL)
                panic("fault_addr set but no fault catcher");
-       else if(arch_fixup(ip, sc))
+        else if(!is_user && arch_fixup(ip, sc))
                return(0);
 
        if(!is_user) 
@@ -171,6 +178,7 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
                si.si_errno = 0;
                si.si_code = BUS_ADRERR;
                si.si_addr = (void *)address;
+                current->thread.arch.faultinfo = fi;
                force_sig_info(SIGBUS, &si, current);
        }
        else if(err == -ENOMEM){
@@ -180,22 +188,20 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
        else {
                si.si_signo = SIGSEGV;
                si.si_addr = (void *) address;
-               current->thread.cr2 = address;
-               current->thread.err = is_write;
+                current->thread.arch.faultinfo = fi;
                force_sig_info(SIGSEGV, &si, current);
        }
        return(0);
 }
 
-void bad_segv(unsigned long address, unsigned long ip, int is_write)
+void bad_segv(struct faultinfo fi, unsigned long ip)
 {
        struct siginfo si;
 
        si.si_signo = SIGSEGV;
        si.si_code = SEGV_ACCERR;
-       si.si_addr = (void *) address;
-       current->thread.cr2 = address;
-       current->thread.err = is_write;
+        si.si_addr = (void *) FAULT_ADDRESS(fi);
+        current->thread.arch.faultinfo = fi;
        force_sig_info(SIGSEGV, &si, current);
 }
 
@@ -204,6 +210,7 @@ void relay_signal(int sig, union uml_pt_regs *regs)
        if(arch_handle_signal(sig, regs)) return;
        if(!UPT_IS_USER(regs))
                panic("Kernel mode signal %d", sig);
+        current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
        force_sig(sig, current);
 }