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authorJohn David Anglin <dave.anglin@nrc-cnrc.gc.ca>2009-08-02 06:34:08 -0400
committerHelge Deller <deller@gmx.de>2009-08-02 06:34:08 -0400
commitb4f2e2ad5348063ef94aa623f6f09b52ecaf0990 (patch)
treec725f839326292875f26fe2bd08cebac0e24b2ee /arch/parisc
parented680c4ad478d0fee9740f7d029087f181346564 (diff)
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>
Diffstat (limited to 'arch/parisc')
-rw-r--r--arch/parisc/kernel/module.c50
1 files changed, 45 insertions, 5 deletions
diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index ef5caf2e6ed0..61ee0eec4e69 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -86,8 +86,12 @@
86 * the bottom of the table, which has a maximum signed displacement of 86 * the bottom of the table, which has a maximum signed displacement of
87 * 0x3fff; however, since we're only going forward, this becomes 87 * 0x3fff; however, since we're only going forward, this becomes
88 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have 88 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
89 * at most 1023 entries */ 89 * at most 1023 entries.
90#define MAX_GOTS 1023 90 * To overcome this 14bit displacement with some kernel modules, we'll
91 * use instead the unusal 16bit displacement method (see reassemble_16a)
92 * which gives us a maximum positive displacement of 0x7fff, and as such
93 * allows us to allocate up to 4095 GOT entries. */
94#define MAX_GOTS 4095
91 95
92/* three functions to determine where in the module core 96/* three functions to determine where in the module core
93 * or init pieces the location is */ 97 * or init pieces the location is */
@@ -145,12 +149,40 @@ struct stub_entry {
145/* The reassemble_* functions prepare an immediate value for 149/* The reassemble_* functions prepare an immediate value for
146 insertion into an opcode. pa-risc uses all sorts of weird bitfields 150 insertion into an opcode. pa-risc uses all sorts of weird bitfields
147 in the instruction to hold the value. */ 151 in the instruction to hold the value. */
152static inline int sign_unext(int x, int len)
153{
154 int len_ones;
155
156 len_ones = (1 << len) - 1;
157 return x & len_ones;
158}
159
160static inline int low_sign_unext(int x, int len)
161{
162 int sign, temp;
163
164 sign = (x >> (len-1)) & 1;
165 temp = sign_unext(x, len-1);
166 return (temp << 1) | sign;
167}
168
148static inline int reassemble_14(int as14) 169static inline int reassemble_14(int as14)
149{ 170{
150 return (((as14 & 0x1fff) << 1) | 171 return (((as14 & 0x1fff) << 1) |
151 ((as14 & 0x2000) >> 13)); 172 ((as14 & 0x2000) >> 13));
152} 173}
153 174
175static inline int reassemble_16a(int as16)
176{
177 int s, t;
178
179 /* Unusual 16-bit encoding, for wide mode only. */
180 t = (as16 << 1) & 0xffff;
181 s = (as16 & 0x8000);
182 return (t ^ s ^ (s >> 1)) | (s >> 15);
183}
184
185
154static inline int reassemble_17(int as17) 186static inline int reassemble_17(int as17)
155{ 187{
156 return (((as17 & 0x10000) >> 16) | 188 return (((as17 & 0x10000) >> 16) |
@@ -407,6 +439,7 @@ static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
407 enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) 439 enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
408{ 440{
409 struct stub_entry *stub; 441 struct stub_entry *stub;
442 int __maybe_unused d;
410 443
411 /* initialize stub_offset to point in front of the section */ 444 /* initialize stub_offset to point in front of the section */
412 if (!me->arch.section[targetsec].stub_offset) { 445 if (!me->arch.section[targetsec].stub_offset) {
@@ -460,12 +493,19 @@ static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
460 */ 493 */
461 switch (stub_type) { 494 switch (stub_type) {
462 case ELF_STUB_GOT: 495 case ELF_STUB_GOT:
463 stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ 496 d = get_got(me, value, addend);
497 if (d <= 15) {
498 /* Format 5 */
499 stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */
500 stub->insns[0] |= low_sign_unext(d, 5) << 16;
501 } else {
502 /* Format 3 */
503 stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */
504 stub->insns[0] |= reassemble_16a(d);
505 }
464 stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ 506 stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */
465 stub->insns[2] = 0xe820d000; /* bve (%r1) */ 507 stub->insns[2] = 0xe820d000; /* bve (%r1) */
466 stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ 508 stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */
467
468 stub->insns[0] |= reassemble_14(get_got(me, value, addend) & 0x3fff);
469 break; 509 break;
470 case ELF_STUB_MILLI: 510 case ELF_STUB_MILLI:
471 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 511 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */