parisc: Fix GOT overflow during module load on 64bit kernel

[pandora-kernel.git] / arch / parisc / kernel / module.c

diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index ef5caf2..61ee0ee 100644 (file)
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -86,8 +86,12 @@
  * the bottom of the table, which has a maximum signed displacement of
  * 0x3fff; however, since we're only going forward, this becomes
  * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
  * the bottom of the table, which has a maximum signed displacement of
  * 0x3fff; however, since we're only going forward, this becomes
  * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have

- * at most 1023 entries */
-#define MAX_GOTS       1023
+ * at most 1023 entries.
+ * To overcome this 14bit displacement with some kernel modules, we'll
+ * use instead the unusal 16bit displacement method (see reassemble_16a)
+ * which gives us a maximum positive displacement of 0x7fff, and as such
+ * allows us to allocate up to 4095 GOT entries. */
+#define MAX_GOTS       4095

 
 /* three functions to determine where in the module core
  * or init pieces the location is */
 
 /* three functions to determine where in the module core
  * or init pieces the location is */


@@ -145,12 +149,40 @@ struct stub_entry {
 /* The reassemble_* functions prepare an immediate value for
    insertion into an opcode. pa-risc uses all sorts of weird bitfields
    in the instruction to hold the value.  */
 /* The reassemble_* functions prepare an immediate value for
    insertion into an opcode. pa-risc uses all sorts of weird bitfields
    in the instruction to hold the value.  */

+static inline int sign_unext(int x, int len)
+{
+       int len_ones;
+
+       len_ones = (1 << len) - 1;
+       return x & len_ones;
+}
+
+static inline int low_sign_unext(int x, int len)
+{
+       int sign, temp;
+
+       sign = (x >> (len-1)) & 1;
+       temp = sign_unext(x, len-1);
+       return (temp << 1) | sign;
+}
+

 static inline int reassemble_14(int as14)
 {
        return (((as14 & 0x1fff) << 1) |
                ((as14 & 0x2000) >> 13));
 }
 
 static inline int reassemble_14(int as14)
 {
        return (((as14 & 0x1fff) << 1) |
                ((as14 & 0x2000) >> 13));
 }
 

+static inline int reassemble_16a(int as16)
+{
+       int s, t;
+
+       /* Unusual 16-bit encoding, for wide mode only.  */
+       t = (as16 << 1) & 0xffff;
+       s = (as16 & 0x8000);
+       return (t ^ s ^ (s >> 1)) | (s >> 15);
+}
+
+

 static inline int reassemble_17(int as17)
 {
        return (((as17 & 0x10000) >> 16) |
 static inline int reassemble_17(int as17)
 {
        return (((as17 & 0x10000) >> 16) |


@@ -407,6 +439,7 @@ static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
        enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
 {
        struct stub_entry *stub;
        enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
 {
        struct stub_entry *stub;

+       int __maybe_unused d;

 
        /* initialize stub_offset to point in front of the section */
        if (!me->arch.section[targetsec].stub_offset) {
 
        /* initialize stub_offset to point in front of the section */
        if (!me->arch.section[targetsec].stub_offset) {


@@ -460,12 +493,19 @@ static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
  */
        switch (stub_type) {
        case ELF_STUB_GOT:
  */
        switch (stub_type) {
        case ELF_STUB_GOT:

-               stub->insns[0] = 0x537b0000;    /* ldd 0(%dp),%dp       */
+               d = get_got(me, value, addend);
+               if (d <= 15) {
+                       /* Format 5 */
+                       stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp  */
+                       stub->insns[0] |= low_sign_unext(d, 5) << 16;
+               } else {
+                       /* Format 3 */
+                       stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp  */
+                       stub->insns[0] |= reassemble_16a(d);
+               }

                stub->insns[1] = 0x53610020;    /* ldd 10(%dp),%r1      */
                stub->insns[2] = 0xe820d000;    /* bve (%r1)            */
                stub->insns[3] = 0x537b0030;    /* ldd 18(%dp),%dp      */
                stub->insns[1] = 0x53610020;    /* ldd 10(%dp),%r1      */
                stub->insns[2] = 0xe820d000;    /* bve (%r1)            */
                stub->insns[3] = 0x537b0030;    /* ldd 18(%dp),%dp      */

-
-               stub->insns[0] |= reassemble_14(get_got(me, value, addend) & 0x3fff);

                break;
        case ELF_STUB_MILLI:
                stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
                break;
        case ELF_STUB_MILLI:
                stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */