It is not possible to change the syscall return value on MIPS
so we cannot support full intercept mode.
Another complication on MIPS is that if a system call is invoked
via syscall(__NR_###), v0 holds __NR_O32_Linux and the real syscall
is in the first arg (a0) and other args are shifted by one.
Define a new sudo setting, `apparmor_profile`, that can be used to pass
in an AppArmor profile that should be used to confine commands. If
apparmor_profile is specified, sudo will execute the command using the
new `apparmor_execve` function, which confines the command under the
provided profile before exec'ing it.
When ptracing a process, we receive the signal-delivery-stop signal
before the group-stop signal. If sudo is running the command in
the same terminal, we need to wait until the stop signal is actually
delivered to the command before we can suspend sudo itself. If we
suspend sudo before receiving the group-stop, the command will be
restarted with PTRACE_LISTEN too late and will miss the SIGCONT
from sudo.
It should also work on s390 but this has not been tested.
I have not added a compat mode to trace 31-bit binaries on s390x
due to the lack of a test system.
Use PTRACE_SETREGSET with NT_ARM_SYSTEM_CALL instead just like we
would for a 64-bit binary. Newer Linux headers don't define
PTRACE_SET_SYSCALL for aarch64.
Mips is a bit different in that most Linux distros appear to use
the n32 ABI on 64-bit CPUs. We don't currently support tracing a
64-bit binary from a 32-bit sudo. We could suport tracing o32
ABI binaries in compat mode, though.
For compat binaries, use the upper 32-bits as the next word instead
of calling ptrace(2) to get it. This reduces the number of ptrace(2)
calls when reading argv and envp for compat binaries.
We align the start of the string table to a word boundary to help
prevent overlap when writing the pointers. However, the actual
strings themselves don't need to be aligned.
In compat mode, if argc is odd, writing the last pointer of argv will
overlap with the address of argv[0], so leave an extra word in between.
Also remove incorrect comments about PTRACE_PEEKDATA unaligned access.
If we try to use the compat word size we can end up in a situation
where a subsequent PTRACE_POKEDATA overwrites part of what we've
already written since it always writes in sizeof(long) units.
We need to define the ptrace register struct ourselves for the
32-bit system since there is no good way to get it from the system
headers. Currently only implemented for x86_64 and aarch64.
We need to continue the traced process even if there is a fatal
error. Otherwise, sudo will appear to hang as the running process
is left in PTRACE_EVENT stop.
Unlike PTRACE_GETREGSET, PTRACE_GETREGS requires that we manually
map registers from 64-bit to 32-bit layouts when running, e.g. a
32-bit binary from a 64-bit sudo process.
