#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:
- case EPERM:
- /* 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;
- }
- }
-
nread = 0;
if (addr & (sizeof(long) - 1)) {
/* addr not a multiple of sizeof(long) */
}
/*
- * 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),
- * else 0 if len bytes were read but no NUL byte seen.
- *
- * Note: there is no guarantee we won't overwrite some bytes
- * in laddr[] _after_ terminating NUL (but, of course,
- * we never write past laddr[len-1]).
+ * Copy `len' bytes of data from process `pid'
+ * at address `addr' to our space at `our_addr'.
*/
int
-umovestr(struct tcb *const tcp, kernel_ulong_t addr, unsigned int len, char *laddr)
+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)
{
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:
- case EPERM:
- /* 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;
- case ESRCH:
- /* the process is gone */
- 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:
-
if (addr & (sizeof(long) - 1)) {
/* addr not a multiple of sizeof(long) */
n = addr & (sizeof(long) - 1); /* residue */
nread += m;
len -= m;
}
+
+ return 0;
+}
+
+/*
+ * 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),
+ * else 0 if len bytes were read but no NUL byte seen.
+ *
+ * Note: there is no guarantee we won't overwrite some bytes
+ * in laddr[] _after_ terminating NUL (but, of course,
+ * we never write past laddr[len-1]).
+ */
+int
+umovestr(struct tcb *const tcp, kernel_ulong_t addr, unsigned int len,
+ char *laddr)
+{
+ if (tracee_addr_is_invalid(addr))
+ return -1;
+
+ const int pid = tcp->pid;
+
+ 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) {
+ /*
+ * 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) {
+ if (memchr(laddr, '\0', r))
+ return 1;
+ addr += r;
+ laddr += r;
+ nread += r;
+ len -= r;
+ continue;
+ }
+ switch (errno) {
+ case ENOSYS:
+ case EPERM:
+ /* try PTRACE_PEEKDATA */
+ if (!nread)
+ return umovestr_peekdata(pid, addr,
+ len, laddr);
+ /* 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;
+ case ESRCH:
+ /* the process is gone */
+ 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;
}
projects / strace / commitdiff