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More select decoding fixes

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* desc.c (decode_select): Actually print arg[0] as int on entering
syscall.  When arg[0] is negative, do not attempt to fetch and decode
descriptor sets on entering syscall, kernel will reject it anyway.
On exiting syscall, stop checking descriptor sets as soon as all
returned descriptors are found.
This commit is contained in:
Дмитрий Левин 2013-11-05 22:46:43 +00:00
parent 1f65c3cd2a
commit f3696b3c8b
1 changed files with 26 additions and 20 deletions
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46
desc.c
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@ -486,31 +486,39 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
const char *sep;
long arg;
/* Kernel truncates arg[0] to int, we do the same */
fdsize = (int)args[0];
/* Kernel truncates arg[0] to int, we do the same. */
nfds = (int) args[0];
/* Kernel rejects negative nfds, so we don't parse it either. */
if (nfds < 0) {
nfds = 0;
fds = NULL;
}
/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
if (fdsize > 1024*1024)
fdsize = 1024*1024;
if (fdsize < 0)
fdsize = 0;
nfds = fdsize;
fdsize = (((fdsize + 7) / 8) + sizeof(long)-1) & -sizeof(long);
/* We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
if (nfds > 1024*1024)
nfds = 1024*1024;
/*
* We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
* Instead of args[0], use nfds for fd count, fdsize for array lengths.
*/
fdsize = (((nfds + 7) / 8) + sizeof(long)-1) & -sizeof(long);
if (entering(tcp)) {
fds = malloc(fdsize);
if (!fds)
die_out_of_memory();
tprintf("%ld", args[0]);
tprintf("%d", (int) args[0]);
if (fdsize > 0) {
fds = malloc(fdsize);
if (!fds)
die_out_of_memory();
}
for (i = 0; i < 3; i++) {
arg = args[i+1];
if (arg == 0) {
tprints(", NULL");
continue;
}
if (!verbose(tcp)) {
if (!verbose(tcp) || !fds) {
tprintf(", %#lx", arg);
continue;
}
@ -536,8 +544,7 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
static char outstr[1024];
char *outptr;
#define end_outstr (outstr + sizeof(outstr))
const char *sep;
long ready_fds;
int ready_fds;
if (syserror(tcp))
return 0;
@ -554,7 +561,7 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
outptr = outstr;
sep = "";
for (i = 0; i < 3; i++) {
for (i = 0; i < 3 && ready_fds > 0; i++) {
int first = 1;
arg = args[i+1];
@ -577,13 +584,12 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
outptr += sprintf(outptr, " %u", j);
}
}
ready_fds--;
if (--ready_fds == 0)
break;
}
}
if (outptr != outstr)
*outptr++ = ']';
if (ready_fds == 0)
break;
}
free(fds);
/* This contains no useful information on SunOS. */