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/* IA64 breakpoint support. Much of this clagged from gdb
* -Ian Wienand <ianw@gelato.unsw.edu.au> 10/3/2005
*/
#include <sys/ptrace.h>
#include <string.h>
#include <assert.h>
#include "breakpoint.h"
#include "debug.h"
static long long
extract_bit_field(char *bundle, int from, int len) {
long long result = 0LL;
int to = from + len;
int from_byte = from / 8;
int to_byte = to / 8;
unsigned char *b = (unsigned char *)bundle;
unsigned char c;
int lshift;
int i;
c = b[from_byte];
if (from_byte == to_byte)
c = ((unsigned char)(c << (8 - to % 8))) >> (8 - to % 8);
result = c >> (from % 8);
lshift = 8 - (from % 8);
for (i = from_byte + 1; i < to_byte; i++) {
result |= ((long long)b[i]) << lshift;
lshift += 8;
}
if (from_byte < to_byte && (to % 8 != 0)) {
c = b[to_byte];
c = ((unsigned char)(c << (8 - to % 8))) >> (8 - to % 8);
result |= ((long long)c) << lshift;
}
return result;
}
/* Replace the specified bits in an instruction bundle */
static void
replace_bit_field(char *bundle, long long val, int from, int len) {
int to = from + len;
int from_byte = from / 8;
int to_byte = to / 8;
unsigned char *b = (unsigned char *)bundle;
unsigned char c;
if (from_byte == to_byte) {
unsigned char left, right;
c = b[from_byte];
left = (c >> (to % 8)) << (to % 8);
right =
((unsigned char)(c << (8 - from % 8))) >> (8 - from % 8);
c = (unsigned char)(val & 0xff);
c = (unsigned char)(c << (from % 8 + 8 - to % 8)) >> (8 -
to % 8);
c |= right | left;
b[from_byte] = c;
} else {
int i;
c = b[from_byte];
c = ((unsigned char)(c << (8 - from % 8))) >> (8 - from % 8);
c = c | (val << (from % 8));
b[from_byte] = c;
val >>= 8 - from % 8;
for (i = from_byte + 1; i < to_byte; i++) {
c = val & 0xff;
val >>= 8;
b[i] = c;
}
if (to % 8 != 0) {
unsigned char cv = (unsigned char)val;
c = b[to_byte];
c = c >> (to % 8) << (to % 8);
c |= ((unsigned char)(cv << (8 - to % 8))) >> (8 -
to % 8);
b[to_byte] = c;
}
}
}
/* Return the contents of slot N (for N = 0, 1, or 2) in
and instruction bundle */
static long long
slotN_contents(char *bundle, int slotnum) {
return extract_bit_field(bundle, 5 + 41 * slotnum, 41);
}
/* Store an instruction in an instruction bundle */
static void
replace_slotN_contents(char *bundle, long long instr, int slotnum) {
replace_bit_field(bundle, instr, 5 + 41 * slotnum, 41);
}
typedef enum instruction_type {
A, /* Integer ALU ; I-unit or M-unit */
I, /* Non-ALU integer; I-unit */
M, /* Memory ; M-unit */
F, /* Floating-point ; F-unit */
B, /* Branch ; B-unit */
L, /* Extended (L+X) ; I-unit */
X, /* Extended (L+X) ; I-unit */
undefined /* undefined or reserved */
} instruction_type;
static enum instruction_type template_encoding_table[32][3] = {
{M, I, I}, /* 00 */
{M, I, I}, /* 01 */
{M, I, I}, /* 02 */
{M, I, I}, /* 03 */
{M, L, X}, /* 04 */
{M, L, X}, /* 05 */
{undefined, undefined, undefined}, /* 06 */
{undefined, undefined, undefined}, /* 07 */
{M, M, I}, /* 08 */
{M, M, I}, /* 09 */
{M, M, I}, /* 0A */
{M, M, I}, /* 0B */
{M, F, I}, /* 0C */
{M, F, I}, /* 0D */
{M, M, F}, /* 0E */
{M, M, F}, /* 0F */
{M, I, B}, /* 10 */
{M, I, B}, /* 11 */
{M, B, B}, /* 12 */
{M, B, B}, /* 13 */
{undefined, undefined, undefined}, /* 14 */
{undefined, undefined, undefined}, /* 15 */
{B, B, B}, /* 16 */
{B, B, B}, /* 17 */
{M, M, B}, /* 18 */
{M, M, B}, /* 19 */
{undefined, undefined, undefined}, /* 1A */
{undefined, undefined, undefined}, /* 1B */
{M, F, B}, /* 1C */
{M, F, B}, /* 1D */
{undefined, undefined, undefined}, /* 1E */
{undefined, undefined, undefined}, /* 1F */
};
union bundle_t {
char cbundle[16];
unsigned long ubundle[2];
};
void
arch_enable_breakpoint(pid_t pid, struct breakpoint *sbp)
{
unsigned long addr = (unsigned long)sbp->addr;
union bundle_t bundle;
int slotnum = (int)(addr & 0x0f) & 0x3;
long long instr;
int template;
debug(1, "Enable Breakpoint at %p)", sbp->addr);
assert(slotnum <= 2);
addr &= ~0x0f;
bundle.ubundle[0] = ptrace(PTRACE_PEEKTEXT, pid, addr, 0);
bundle.ubundle[1] = ptrace(PTRACE_PEEKTEXT, pid, addr + 8, 0);
/* Check for L type instruction in 2nd slot, if present then
bump up the slot number to the 3rd slot */
template = extract_bit_field(bundle.cbundle, 0, 5);
if (slotnum == 1 && template_encoding_table[template][1] == L) {
slotnum = 2;
}
instr = slotN_contents(bundle.cbundle, slotnum);
memcpy(sbp->orig_value, &instr, sizeof(instr));
replace_slotN_contents(bundle.cbundle, 0x00002000040LL, slotnum);
ptrace(PTRACE_POKETEXT, pid, addr, bundle.ubundle[0]);
ptrace(PTRACE_POKETEXT, pid, addr + 8, bundle.ubundle[1]);
}
void
arch_disable_breakpoint(pid_t pid, const struct breakpoint *sbp)
{
unsigned long addr = (unsigned long)sbp->addr;
int slotnum = (int)(addr & 0x0f) & 0x3;
union bundle_t bundle;
unsigned long instr;
debug(1, "Disable Breakpoint at %p", sbp->addr);
addr &= ~0x0f;
bundle.ubundle[0] = ptrace(PTRACE_PEEKTEXT, pid, addr, 0);
bundle.ubundle[1] = ptrace(PTRACE_PEEKTEXT, pid, addr + 8, 0);
memcpy(&instr, sbp->orig_value, sizeof(instr));
replace_slotN_contents(bundle.cbundle, instr, slotnum);
ptrace(PTRACE_POKETEXT, pid, addr, bundle.ubundle[0]);
ptrace(PTRACE_POKETEXT, pid, addr + 8, bundle.ubundle[1]);
}
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