mips o32: do not bail out in get_syscall_args if umoven fails

If the kernel contains commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3,
both PTRACE_PEEKDATA and process_vm_readv become unavailable when the
process dumpable flag is cleared.  As the first 4 syscall arguments are
still available via registers, do not treat this as get_syscall_args
error.

This condition is triggered and therefore tested by prctl-dumpable test.

* linux/mips/get_syscall_args.c (get_syscall_args) [LINUX_MIPSO32]:
Do not bail out if umoven fails.
This commit is contained in:
Дмитрий Левин 2017-08-18 14:30:08 +00:00
parent dac32d406f
commit 25f91fd854

View File

@ -14,11 +14,16 @@ get_syscall_args(struct tcb *tcp)
tcp->u_arg[1] = mips_REG_A1;
tcp->u_arg[2] = mips_REG_A2;
tcp->u_arg[3] = mips_REG_A3;
if (tcp->s_ent->nargs > 4) {
if (umoven(tcp, mips_REG_SP + 4 * 4,
(tcp->s_ent->nargs - 4) * sizeof(tcp->u_arg[0]),
&tcp->u_arg[4]) < 0)
return -1;
if (tcp->s_ent->nargs > 4
&& umoven(tcp, mips_REG_SP + 4 * sizeof(tcp->u_arg[0]),
(tcp->s_ent->nargs - 4) * sizeof(tcp->u_arg[0]),
&tcp->u_arg[4]) < 0) {
/*
* Let's proceed with the first 4 arguments
* instead of reporting the failure.
*/
memset(&tcp->u_arg[4], 0,
(tcp->s_ent->nargs - 4) * sizeof(tcp->u_arg[0]));
}
#else
# error unsupported mips abi