ack/plat/osxppc/libsys/sigaction.s
George Koehler 02fb480217 Commit a preview of osx386 and osxppc as new platforms.
These produce Mach-o executables for Mac OS X on Intel or PowerPC
processors.  Our code generator for PowerPC (mach/powerpc) still has
bugs.  Some examples seem to run, but startrek crashes.  Our code
generator for Intel (mach/i386) is better.

There is a problem with job control.  If you run paranoia or startrek,
then suspend the job (^Z) and resume it ('fg' in bash), then read(2)
might fail with EINTR.

The larger files in this commit are
 - plat/osx/cvmach/cvmach.c
 - plat/osx/libsys/brk.c
 - plat/osx386/libsys/sigaction.s
 - plat/osxppc/libsys/sigaction.s
2016-10-02 14:58:05 -04:00

60 lines
1.3 KiB
ArmAsm

#define IFTRUE 12
#define ALWAYS 20
#define EQ 2
! OS X, unlike FreeBSD, requires us to provide our own signal
! trampoline. We must change the new action from a struct sigaction
! to a bigger struct that includes the trampoline.
.sect .text
.define _sigaction
_sigaction:
addi r0, r0, 46 ! sigaction
lwz r3, 0(sp) ! sig
lwz r4, 4(sp) ! ptr to new action
lwz r5, 8(sp) ! ptr to old action
or. r6, r4, r4
bc IFTRUE, EQ, 1f ! skip if new action is NULL
! We may use the "red zone" from -224(sp) to 0(sp).
addi r4, sp, -16 ! r4 = bigger struct
lwz r7, 0(r6)
stw r7, 0(r4) ! sa_handler
li32 r7, trampoline
stw r7, 4(r4) ! sa_tramp
lwz r7, 4(r6)
stw r7, 8(r4) ! sa_mask
lwz r7, 8(r6)
stw r7, 12(r4) ! sa_flags
1:
sc 0
b .set_errno
bclr 20, 0, 0
trampoline:
! r3 = handler
! r4 = info style
! r5 = sig
! r6 = info
! r7 = context
or r31, r4, r4 ! ack preserves r30, r31
or r30, r7, r7
! Call handler(sig, info, context).
mtspr ctr, r3
stwu r7, -4(sp) ! ack expects arguments on stack
stwu r6, -4(sp)
stwu r5, -4(sp)
bcctrl ALWAYS, 0, 0
! Return from trampoline.
addi r0, r0, 184 ! sigreturn
or r3, r30, r30 ! context
or r4, r31, r31 ! info style
sc 0
ori r0, r0, 0 ! nop
! Only if sigreturn() fails:
addi r0, r0, 1 ! exit
sc 0