boundary. It must be on at least an 8 byte boundary so that the length
of the signal code is a multiple of 8 (well aligned). The size is used
in the calculation of the address of the argument and environment vectors
on the user stack; getting it wrong results in the string pointers being
misaligned and causes alignment faults in getenv() among other things.
Allocate a regular stack frame below the signal frame on the user stack
and join up the frame pointer to the previous frame. This fixes longjmp-ing
out of signal handlers. Longjmp traverses the stack upwards in order to
find the right frame to return to, so the frame pointers must join up
seamlessly. I thought this would just work, but obviously the frame
needs to be below the signal frame, not above it like before. Account
for the extra space in the signal code.
Preload pointers to interrupt data structures in interrupt globals.
This avoids the need to load the pointers from memory in the vectored
interrupt trap handler.
Transfer the first 2 out registers into td_retval in setregs. We use
the same registers for system call arguments as return values, so these
registers got clobbered by the system call return values on return from
execve. They now get clobbered by the right values. We must put the values
in both the out registers in the trapframe and in td_retval because init
calls exec but fails to transfer the return value into the out registers.
This fixes a bug where the first exec after init would pass junk to the
c runtime, instead of a pointer to the argument strings. A better solution
would be to return EJUSTRETURN on success from execve.
Adjust for change in pmap_bootstraps prototype.
Map the message buffer after the trap table is setup. We will fault
on it immediately.
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