diff options
Diffstat (limited to '')
| -rw-r--r-- | sctrace.c | 134 |
1 files changed, 55 insertions, 79 deletions
@@ -5,6 +5,7 @@ #include <sys/ptrace.h> #include <sys/syscall.h> +#include <sys/uio.h> #include <sys/user.h> #include <sys/wait.h> #include <ctype.h> @@ -57,93 +58,70 @@ usage(void) static char * -get_string_or_memory(pid_t pid, unsigned long int addr, size_t m, int string, const char **errorp) +get_string(pid_t pid, unsigned long int addr, size_t *lenp, const char **errorp) { - /* TODO use process_vm_readv if supported */ - - size_t orig_addr = (size_t)addr; - size_t off; - char *ret = NULL; - size_t size = 0; - size_t len = 0; - size_t i; - union { - long int value; - char bytes[sizeof(long int)]; - } u; - + struct iovec inv, outv; + size_t off = 0, size = 0, page_off, read_size; + char *out = NULL, *in = (char *)addr, *p; + page_off = (size_t)addr - ((size_t)addr & -sizeof(PAGE_SIZE)); + read_size = PAGE_SIZE - page_off; *errorp = NULL; - - if (!addr) - return NULL; - - addr &= -sizeof(long int); - off = orig_addr - (size_t)addr; - - for (;;) { - errno = 0; - u.value = ptrace(PTRACE_PEEKDATA, pid, addr, 0); - switch (errno) { - case 0: - break; - case EFAULT: - *errorp = "<invalid address>"; - return NULL; - default: - *errorp = "<an error occured during reading of string>"; - return NULL; + for (;; read_size = PAGE_SIZE) { + out = realloc(out, size + PAGE_SIZE); + if (!out) { + fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno)); + exit(1); } - - addr += sizeof(long int); - if (size - len < sizeof(long int)) { - ret = realloc(ret, size += sizeof(long int) * 32); - if (!ret) { - fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno)); - exit(1); - } + inv.iov_base = &in[off]; + inv.iov_len = read_size; + outv.iov_base = &out[off]; + outv.iov_len = read_size; + if (process_vm_readv(pid, &outv, 1, &inv, 1, 0) != (ssize_t)read_size) { + *errorp = errno == EFAULT ? "<invalid address>" : "<an error occured during reading of string>"; + *lenp = 0; + return 0; } - if (string) { - for (i = off; i < sizeof(u.bytes); i++, len++) { - ret[len] = u.bytes[i]; - if (!ret[len]) - return ret; - } - } else { - for (i = off; i < sizeof(u.bytes) && len < m; i++, len++) - ret[len] = u.bytes[i]; - if (len == m) - return ret; + p = memchr(&out[off], 0, read_size); + if (p) { + *lenp = (size_t)(p - out); + return out; } - off = 0; + off += read_size; } } -static char * -get_memory(pid_t pid, unsigned long int addr, size_t m, const char **errorp) +static int +get_struct(pid_t pid, unsigned long int addr, void *out, size_t size, const char **errorp) { - return get_string_or_memory(pid, addr, m, 0, errorp); + struct iovec inv, outv; + *errorp = NULL; + inv.iov_base = (void *)addr; + inv.iov_len = size; + outv.iov_base = out; + outv.iov_len = size; + if (process_vm_readv(pid, &outv, 1, &inv, 1, 0) == size) + return 0; + *errorp = errno == EFAULT ? "<invalid address>" : "<an error occured during reading of string>"; + return -1; } - static char * -get_string(pid_t pid, unsigned long int addr, const char **errorp) +get_memory(pid_t pid, unsigned long int addr, size_t n, const char **errorp) { - return get_string_or_memory(pid, addr, 0, 1, errorp); + char *out = malloc(n + (size_t)!n); + if (!out) { + fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(errno)); + exit(1); + } + if (get_struct(pid, addr, out, n, errorp)) { + free(out); + return NULL; + } + return out; } -static int -get_struct(pid_t pid, unsigned long int addr, void *out, size_t size, const char **errorp) -{ - char *data = get_string_or_memory(pid, addr, size, 0, errorp); - if (!data) - return -1; - memcpy(out, data, size); - free(data); - return 0; -} - static void add_char(char **strp, size_t *sizep, size_t *lenp, char c) @@ -272,13 +250,6 @@ escape_memory(char *str, size_t m) } -static char * -escape_string(char *str) -{ - return escape_memory(str, str ? strlen(str) : 0); -} - - static void fprint_clockid(FILE *fp, pid_t pid, unsigned long int args[6], size_t arg_index) /* TODO */ { @@ -305,7 +276,7 @@ fprint_systemcall(FILE *fp, pid_t pid, const char *scall, const char *fmt, unsig { typedef char *(*Function)(FILE *fp, pid_t pid, unsigned long int args[6], size_t arg_index); Function funcs[6]; - size_t i, nfuncs = 0, func; + size_t i, nfuncs = 0, func, len; int ells = 0; char *str; const char *err; @@ -341,7 +312,8 @@ fprint_systemcall(FILE *fp, pid_t pid, const char *scall, const char *fmt, unsig funcs[nfuncs++] = va_arg(ap, Function); funcs[func - 1](fp, pid, args, i); } else if (*fmt == 's') { - str = escape_string(get_string(pid, args[i], &err)); + str = get_string(pid, args[i], &len, &err); + str = escape_memory(str, len); fprintf(fp, "%s", str ? str : err); free(str); } else if (*fmt == 'm') { @@ -426,6 +398,7 @@ print_systemcall(FILE *fp, pid_t pid, unsigned long long int scall, unsigned lon *ret_type = Unknown; + /* TODO replace GENERIC_HANDLER with specific handlers */ switch (scall) { GENERIC_HANDLER(_sysctl); SIMPLE(accept, "ipp", Int); /* TODO output */ @@ -808,6 +781,9 @@ main(int argc, char **argv) FILE *outfp = stderr; const char *num = NULL; + /* TODO add option to trace children */ + /* TODO add option to trace threads */ + /* TODO add option to specify argv[0] */ ARGBEGIN { case 'f': if (outfile) |