1*cf84ac9aSAndroid Build Coastguard Worker /* Return codes: 1 - ok, 0 - ignore, other - error. */
2*cf84ac9aSAndroid Build Coastguard Worker static int
arch_get_scno(struct tcb * tcp)3*cf84ac9aSAndroid Build Coastguard Worker arch_get_scno(struct tcb *tcp)
4*cf84ac9aSAndroid Build Coastguard Worker {
5*cf84ac9aSAndroid Build Coastguard Worker kernel_ulong_t scno = 0;
6*cf84ac9aSAndroid Build Coastguard Worker
7*cf84ac9aSAndroid Build Coastguard Worker /*
8*cf84ac9aSAndroid Build Coastguard Worker * In the new syscall ABI, the system call number is in R3.
9*cf84ac9aSAndroid Build Coastguard Worker */
10*cf84ac9aSAndroid Build Coastguard Worker if (upeek(tcp, 4*(REG_REG0+3), &scno) < 0)
11*cf84ac9aSAndroid Build Coastguard Worker return -1;
12*cf84ac9aSAndroid Build Coastguard Worker
13*cf84ac9aSAndroid Build Coastguard Worker if ((long) scno < 0) {
14*cf84ac9aSAndroid Build Coastguard Worker /* Odd as it may seem, a glibc bug has been known to cause
15*cf84ac9aSAndroid Build Coastguard Worker glibc to issue bogus negative syscall numbers. So for
16*cf84ac9aSAndroid Build Coastguard Worker our purposes, make strace print what it *should* have been */
17*cf84ac9aSAndroid Build Coastguard Worker kernel_ulong_t correct_scno = (scno & 0xff);
18*cf84ac9aSAndroid Build Coastguard Worker if (debug_flag)
19*cf84ac9aSAndroid Build Coastguard Worker error_msg("Detected glibc bug: bogus system call"
20*cf84ac9aSAndroid Build Coastguard Worker " number = %ld, correcting to %ld",
21*cf84ac9aSAndroid Build Coastguard Worker scno, correct_scno);
22*cf84ac9aSAndroid Build Coastguard Worker scno = correct_scno;
23*cf84ac9aSAndroid Build Coastguard Worker }
24*cf84ac9aSAndroid Build Coastguard Worker
25*cf84ac9aSAndroid Build Coastguard Worker tcp->scno = scno;
26*cf84ac9aSAndroid Build Coastguard Worker return 1;
27*cf84ac9aSAndroid Build Coastguard Worker }
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