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

Signed-off-by: John David Anglin <dave.anglin@nrc-cnrc.gc.ca>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
John David Anglin 2009-08-02 12:34:08 +02:00 committed by Helge Deller
parent ed680c4ad4
commit b4f2e2ad53
1 changed files with 45 additions and 5 deletions
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50
arch/parisc/kernel/module.c
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@ -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
* 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 */
@ -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. */
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_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) |
@ -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;
int __maybe_unused d;
/* 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:
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[0] |= reassemble_14(get_got(me, value, addend) & 0x3fff);
break;
case ELF_STUB_MILLI:
stub->insns[0] = 0x20200000; /* ldil 0,%r1 */