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vm: suppress signal-handler stack frame generation 

This is a hack; see #295
db4
Joe Groff 2011-10-25 19:52:47 -07:00
parent 7bd7d0234d
commit d6eae2f42d
2 changed files with 32 additions and 21 deletions
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47
basis/cpu/x86/64/bootstrap.factor
View File

@ -39,9 +39,9 @@ IN: bootstrap.x86
! alignment
RSP stack-frame-size bootstrap-cell - SUB
! store entry point
RSP stack-frame-size bootstrap-cell 3 * - [+] RAX MOV
RSP stack-frame-size 3 bootstrap-cells - [+] RAX MOV
! store stack frame size
RSP stack-frame-size bootstrap-cell 2 * - [+] stack-frame-size MOV
RSP stack-frame-size 2 bootstrap-cells - [+] stack-frame-size MOV
] jit-prolog jit-define
[
@ -93,46 +93,53 @@ IN: bootstrap.x86
USE: locals
:: jit-save-volatile-regs ( -- save-size )
:: jit-save-volatile-regs ( -- frame-size )
! do we also need to save XMM?
volatile-regs length bootstrap-cell * 16 align :> save-size
RSP 2 bootstrap-cells [+] save-size ADD ! bump up stack frame size
RSP save-size SUB
volatile-regs length bootstrap-cells 16 align stack-frame-size + :> frame-size
RSP frame-size bootstrap-cell - SUB ! minus a cell for return address
volatile-regs
[| r i | RSP i bootstrap-cell * [+] r MOV ] each-index
save-size ;
[| r i | RSP i bootstrap-cells [+] r MOV ] each-index
! Now that the registers are saved, we can make the stack frame
RAX 0 MOV rc-absolute-cell rel-this
RSP frame-size 3 bootstrap-cells - [+] RAX MOV
RSP frame-size 2 bootstrap-cells - [+] frame-size MOV
frame-size ;
:: jit-restore-volatile-regs ( save-size -- )
:: jit-restore-volatile-regs ( frame-size -- )
volatile-regs
[| r i | r RSP i bootstrap-cell * [+] MOV ] each-index
RSP save-size ADD ;
[| r i | r RSP i bootstrap-cells [+] MOV ] each-index
RSP frame-size bootstrap-cell - ADD ;
! The signal-handler and leaf-signal-handler subprimitives are special-cased
! in vm/quotations.cpp not to trigger generation of a stack frame, so they can
! peform their own prolog/epilog preserving registers.
[| |
jit-save-volatile-regs :> save-size
jit-save-volatile-regs :> frame-size
jit-save-context
RAX vm-reg vm-signal-handler-addr-offset [+] MOV
RAX CALL
save-size jit-restore-volatile-regs
frame-size jit-restore-volatile-regs
] \ signal-handler define-sub-primitive
[| |
jit-save-volatile-regs :> save-size
jit-save-volatile-regs :> frame-size
jit-save-context
RAX vm-reg vm-signal-handler-addr-offset [+] MOV
RAX CALL
! Stack at this point has a fake stack frame set up to represent the
! leaf procedure we interrupted. We must tear down that frame in
! addition to our own before resuming.
! Grab our resume address and place it just underneath the leaf proc's
! Grab our frame's return address and place it just underneath the leaf proc's
! return address, since we can't touch any registers once they've been
! restored. If we got this far there should be no faults here and we
! can get away with corrupting the stack frame.
RAX RSP save-size 3 bootstrap-cells + [+] MOV
RSP save-size 6 bootstrap-cells + [+] RAX MOV
RAX RSP frame-size bootstrap-cell - [+] MOV
RSP frame-size 2 bootstrap-cells + [+] RAX MOV
! Popping 3 extra cells here plus the 3 cells the epilogue pops leaves
! the resume address at the top of the stack for when the epilogue RETs.
save-size 3 bootstrap-cells + jit-restore-volatile-regs
! Popping 3 extra cells here leaves the resume address at the top of the stack
! when we RET.
frame-size 3 bootstrap-cells + jit-restore-volatile-regs
] \ leaf-signal-handler define-sub-primitive
[

6
vm/quotations.cpp
View File

@ -84,7 +84,11 @@ bool quotation_jit::declare_p(cell i, cell length)
bool quotation_jit::word_stack_frame_p(cell obj)
{
return to_boolean(untag<word>(obj)->subprimitive)
// Subprimitives should be flagged with whether they require a stack frame.
// See #295.
return (to_boolean(untag<word>(obj)->subprimitive)
&& obj != parent->special_objects[SIGNAL_HANDLER_WORD]
&& obj != parent->special_objects[LEAF_SIGNAL_HANDLER_WORD])
|| obj == parent->special_objects[JIT_PRIMITIVE_WORD];
}