* Copyright (c) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Linux for s390 port by D.J. Barrow
* <barrow_dj@mail.yahoo.com,djbarrow@de.ibm.com>
- * Copyright (c) 1999-2017 The strace developers.
+ * Copyright (c) 1999-2018 The strace developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
.iov_len = len
};
- return process_vm_readv(pid, &local, 1, &remote, 1, 0);
+ const ssize_t rc = process_vm_readv(pid, &local, 1, &remote, 1, 0);
+ if (rc < 0 && errno == ENOSYS)
+ process_vm_readv_not_supported = true;
+
+ return rc;
}
static bool
#endif
}
-/*
- * Copy `len' bytes of data from process `pid'
- * at address `addr' to our space at `our_addr'.
- */
-int
-umoven(struct tcb *const tcp, kernel_ulong_t addr, unsigned int len,
- void *const our_addr)
+/* legacy method of copying from tracee */
+static int
+umoven_peekdata(const int pid, kernel_ulong_t addr, unsigned int len,
+ void *laddr)
{
- char *laddr = our_addr;
- int pid = tcp->pid;
- unsigned int n, m, nread;
- union {
- long val;
- char x[sizeof(long)];
- } u;
-
- if (tracee_addr_is_invalid(addr))
- return -1;
-
- if (!process_vm_readv_not_supported) {
- int r = vm_read_mem(pid, laddr, addr, len);
- if ((unsigned int) r == len)
- return 0;
- if (r >= 0) {
- error_msg("umoven: short read (%u < %u) @0x%" PRI_klx,
- (unsigned int) r, len, addr);
- return -1;
- }
- switch (errno) {
- case ENOSYS:
- /* never try it again */
- process_vm_readv_not_supported = 1;
- break;
- case EPERM:
- /* operation not permitted, try PTRACE_PEEKDATA */
- break;
- case ESRCH:
- /* the process is gone */
- return -1;
- case EFAULT: case EIO:
- /* address space is inaccessible */
- return -1;
- default:
- /* all the rest is strange and should be reported */
- perror_msg("process_vm_readv: pid:%d @0x%" PRI_klx,
- pid, addr);
- return -1;
- }
- }
+ 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 */
+ 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;
return -1;
case EFAULT: case EIO: case EPERM:
/* address space is inaccessible */
+ if (nread) {
+ perror_msg("umoven: short read (%u < %u) @0x%" PRI_klx,
+ nread, nread + len, addr - nread);
+ }
return -1;
default:
/* all the rest is strange and should be reported */
pid, addr);
return -1;
}
- m = MIN(sizeof(long) - n, len);
- memcpy(laddr, &u.x[n], m);
+
+ unsigned int m = MIN(sizeof(long) - residue, len);
+ memcpy(laddr, &u.x[residue], m);
+ residue = 0;
addr += sizeof(long);
laddr += m;
nread += m;
len -= m;
}
+
+ return 0;
+}
+
+/*
+ * Copy `len' bytes of data from process `pid'
+ * at address `addr' to our space at `our_addr'.
+ */
+int
+umoven(struct tcb *const tcp, kernel_ulong_t addr, unsigned int len,
+ void *const our_addr)
+{
+ if (tracee_addr_is_invalid(addr))
+ return -1;
+
+ const int pid = tcp->pid;
+
+ if (process_vm_readv_not_supported)
+ return umoven_peekdata(pid, addr, len, our_addr);
+
+ int r = vm_read_mem(pid, our_addr, addr, len);
+ if ((unsigned int) r == len)
+ return 0;
+ if (r >= 0) {
+ error_msg("umoven: short read (%u < %u) @0x%" PRI_klx,
+ (unsigned int) r, len, addr);
+ return -1;
+ }
+ switch (errno) {
+ case ENOSYS:
+ case EPERM:
+ /* try PTRACE_PEEKDATA */
+ return umoven_peekdata(pid, addr, len, our_addr);
+ case ESRCH:
+ /* the process is gone */
+ return -1;
+ case EFAULT: case EIO:
+ /* address space is inaccessible */
+ return -1;
+ default:
+ /* all the rest is strange and should be reported */
+ perror_msg("process_vm_readv: pid:%d @0x%" PRI_klx,
+ pid, addr);
+ return -1;
+ }
+}
+
+/*
+ * Like umoven_peekdata but make the additional effort of looking
+ * for a terminating zero byte.
+ */
+static int
+umovestr_peekdata(const int pid, kernel_ulong_t addr, unsigned int len,
+ void *laddr)
+{
+ unsigned int nread = 0;
+ unsigned int residue = addr & (sizeof(long) - 1);
+ void *const orig_addr = laddr;
+
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;
case EFAULT: case EIO: case EPERM:
/* address space is inaccessible */
if (nread) {
- perror_msg("umoven: short read (%u < %u) @0x%" PRI_klx,
+ perror_msg("umovestr: short read (%d < %d) @0x%" PRI_klx,
nread, nread + len, addr - nread);
}
return -1;
default:
/* all the rest is strange and should be reported */
- perror_msg("umoven: PTRACE_PEEKDATA pid:%d @0x%" PRI_klx,
- pid, addr);
+ perror_msg("umovestr: PTRACE_PEEKDATA pid:%d @0x%" PRI_klx,
+ 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);
+ while (residue < sizeof(long))
+ if (u.x[residue++] == '\0')
+ return (laddr - orig_addr) + residue;
+ residue = 0;
addr += sizeof(long);
laddr += m;
nread += m;
* Like `umove' but make the additional effort of looking
* for a terminating zero byte.
*
- * Returns < 0 on error, > 0 if NUL was seen,
- * (TODO if useful: return count of bytes including NUL),
+ * Returns < 0 on error, strlen + 1 if NUL was seen,
* else 0 if len bytes were read but no NUL byte seen.
*
* Note: there is no guarantee we won't overwrite some bytes
* we never write past laddr[len-1]).
*/
int
-umovestr(struct tcb *const tcp, kernel_ulong_t addr, unsigned int len, char *laddr)
+umovestr(struct tcb *const tcp, kernel_ulong_t addr, unsigned int len,
+ char *laddr)
{
- const unsigned long x01010101 = (unsigned long) 0x0101010101010101ULL;
- const unsigned long x80808080 = (unsigned long) 0x8080808080808080ULL;
-
- int pid = tcp->pid;
- unsigned int n, m, nread;
- union {
- unsigned long val;
- char x[sizeof(long)];
- } u;
-
if (tracee_addr_is_invalid(addr))
return -1;
- nread = 0;
- if (!process_vm_readv_not_supported) {
- const size_t page_size = get_pagesize();
- const size_t page_mask = page_size - 1;
-
- while (len > 0) {
- unsigned int chunk_len;
- unsigned int end_in_page;
-
- /*
- * Don't cross pages, otherwise we can get EFAULT
- * and fail to notice that terminating NUL lies
- * in the existing (first) page.
- */
- chunk_len = len > page_size ? page_size : len;
- end_in_page = (addr + chunk_len) & page_mask;
- if (chunk_len > end_in_page) /* crosses to the next page */
- chunk_len -= end_in_page;
-
- int r = vm_read_mem(pid, laddr, addr, chunk_len);
- if (r > 0) {
- if (memchr(laddr, '\0', r))
- return 1;
- addr += r;
- laddr += r;
- nread += r;
- len -= r;
- continue;
- }
- switch (errno) {
- case ENOSYS:
- /* never try it again */
- process_vm_readv_not_supported = 1;
- goto vm_readv_didnt_work;
- case ESRCH:
- /* the process is gone */
- return -1;
- case EPERM:
- /* operation not permitted, try PTRACE_PEEKDATA */
- if (!nread)
- goto vm_readv_didnt_work;
- /* fall through */
- case EFAULT: case EIO:
- /* address space is inaccessible */
- if (nread) {
- perror_msg("umovestr: short read (%d < %d) @0x%" PRI_klx,
- nread, nread + len, addr - nread);
- }
- return -1;
- default:
- /* all the rest is strange and should be reported */
- perror_msg("process_vm_readv: pid:%d @0x%" PRI_klx,
- pid, addr);
- return -1;
- }
- }
- return 0;
- }
- vm_readv_didnt_work:
+ const int pid = tcp->pid;
- 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;
- }
+ if (process_vm_readv_not_supported)
+ return umovestr_peekdata(pid, addr, len, laddr);
+
+ const size_t page_size = get_pagesize();
+ const size_t page_mask = page_size - 1;
+ unsigned int nread = 0;
while (len) {
- errno = 0;
- u.val = ptrace(PTRACE_PEEKDATA, pid, addr, 0);
+ /*
+ * Don't cross pages, otherwise we can get EFAULT
+ * and fail to notice that terminating NUL lies
+ * in the existing (first) page.
+ */
+ unsigned int chunk_len = len > page_size ? page_size : len;
+ unsigned int end_in_page = (addr + chunk_len) & page_mask;
+ if (chunk_len > end_in_page) /* crosses to the next page */
+ chunk_len -= end_in_page;
+
+ int r = vm_read_mem(pid, laddr, addr, chunk_len);
+ if (r > 0) {
+ char *nul_addr = memchr(laddr, '\0', r);
+
+ if (nul_addr)
+ return (nul_addr - laddr) + 1;
+ addr += r;
+ laddr += r;
+ nread += r;
+ len -= r;
+ continue;
+ }
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:
+ case ENOSYS:
+ case EPERM:
+ /* try PTRACE_PEEKDATA */
+ if (!nread)
+ return umovestr_peekdata(pid, addr,
+ len, laddr);
+ ATTRIBUTE_FALLTHROUGH;
+ case EFAULT: case EIO:
/* address space is inaccessible */
- if (nread) {
+ if (nread)
perror_msg("umovestr: short read (%d < %d) @0x%" PRI_klx,
nread, nread + len, addr - nread);
- }
+ return -1;
+ case ESRCH:
+ /* the process is gone */
return -1;
default:
/* all the rest is strange and should be reported */
- perror_msg("umovestr: PTRACE_PEEKDATA pid:%d @0x%" PRI_klx,
- pid, addr);
+ perror_msg("process_vm_readv: pid:%d @0x%" PRI_klx,
+ 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;
- addr += sizeof(long);
- laddr += m;
- nread += m;
- len -= m;
}
+
return 0;
}
projects / strace / blobdiff