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ucopy: cleanup umoven_peekdata and umovestr_peekdata

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* ucopy.c (umoven_peekdata, umovestr_peekdata): Merge aligned
and unaligned tracee address cases.
This commit is contained in:
Дмитрий Левин 2017-07-31 18:25:00 +00:00
parent 9688f6a30d
commit ce822389af
1 changed files with 29 additions and 84 deletions
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113
ucopy.c
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@ -106,44 +106,18 @@ static int
umoven_peekdata(const int pid, kernel_ulong_t addr, unsigned int len,
void *laddr)
{
unsigned int n, m, nread;
union {
long val;
char x[sizeof(long)];
} u;
unsigned int nread = 0;
unsigned int residue = addr & (sizeof(long) - 1);
nread = 0;
if (addr & (sizeof(long) - 1)) {
/* addr not a multiple of sizeof(long) */
n = addr & (sizeof(long) - 1); /* residue */
addr &= -sizeof(long); /* aligned address */
errno = 0;
u.val = ptrace(PTRACE_PEEKDATA, pid, addr, 0);
switch (errno) {
case 0:
break;
case ESRCH: case EINVAL:
/* these could be seen if the process is gone */
return -1;
case EFAULT: case EIO: case EPERM:
/* address space is inaccessible */
return -1;
default:
/* all the rest is strange and should be reported */
perror_msg("umoven: PTRACE_PEEKDATA pid:%d @0x%" PRI_klx,
pid, addr);
return -1;
}
m = MIN(sizeof(long) - n, len);
memcpy(laddr, &u.x[n], m);
addr += sizeof(long);
laddr += m;
nread += m;
len -= m;
}
while (len) {
addr &= -sizeof(long); /* aligned address */
errno = 0;
u.val = ptrace(PTRACE_PEEKDATA, pid, addr, 0);
union {
long val;
char x[sizeof(long)];
} u = { .val = ptrace(PTRACE_PEEKDATA, pid, addr, 0) };
switch (errno) {
case 0:
break;
@ -163,8 +137,10 @@ umoven_peekdata(const int pid, kernel_ulong_t addr, unsigned int len,
pid, addr);
return -1;
}
m = MIN(sizeof(long), len);
memcpy(laddr, u.x, m);
unsigned int m = MIN(sizeof(long) - residue, len);
memcpy(laddr, &u.x[residue], m);
residue = 0;
addr += sizeof(long);
laddr += m;
nread += m;
@ -225,51 +201,18 @@ static int
umovestr_peekdata(const int pid, kernel_ulong_t addr, unsigned int len,
void *laddr)
{
const unsigned long x01010101 = (unsigned long) 0x0101010101010101ULL;
const unsigned long x80808080 = (unsigned long) 0x8080808080808080ULL;
unsigned int n, m, nread;
union {
unsigned long val;
char x[sizeof(long)];
} u;
nread = 0;
if (addr & (sizeof(long) - 1)) {
/* addr not a multiple of sizeof(long) */
n = addr & (sizeof(long) - 1); /* residue */
addr &= -sizeof(long); /* aligned address */
errno = 0;
u.val = ptrace(PTRACE_PEEKDATA, pid, addr, 0);
switch (errno) {
case 0:
break;
case ESRCH: case EINVAL:
/* these could be seen if the process is gone */
return -1;
case EFAULT: case EIO: case EPERM:
/* address space is inaccessible */
return -1;
default:
/* all the rest is strange and should be reported */
perror_msg("umovestr: PTRACE_PEEKDATA pid:%d @0x%" PRI_klx,
pid, addr);
return -1;
}
m = MIN(sizeof(long) - n, len);
memcpy(laddr, &u.x[n], m);
while (n & (sizeof(long) - 1))
if (u.x[n++] == '\0')
return 1;
addr += sizeof(long);
laddr += m;
nread += m;
len -= m;
}
unsigned int nread = 0;
unsigned int residue = addr & (sizeof(long) - 1);
while (len) {
addr &= -sizeof(long); /* aligned address */
errno = 0;
u.val = ptrace(PTRACE_PEEKDATA, pid, addr, 0);
union {
unsigned long val;
char x[sizeof(long)];
} u = { .val = ptrace(PTRACE_PEEKDATA, pid, addr, 0) };
switch (errno) {
case 0:
break;
@ -289,11 +232,13 @@ umovestr_peekdata(const int pid, kernel_ulong_t addr, unsigned int len,
pid, addr);
return -1;
}
m = MIN(sizeof(long), len);
memcpy(laddr, u.x, m);
/* "If a NUL char exists in this word" */
if ((u.val - x01010101) & ~u.val & x80808080)
return 1;
unsigned int m = MIN(sizeof(long) - residue, len);
memcpy(laddr, &u.x[residue], m);
while (residue < sizeof(long))
if (u.x[residue++] == '\0')
return 1;
residue = 0;
addr += sizeof(long);
laddr += m;
nread += m;