Index: config/i386/morestack.S =================================================================== --- config/i386/morestack.S (revision 164260) +++ config/i386/morestack.S (working copy) @@ -1,5 +1,5 @@ # x86/x86_64 support for -fsplit-stack. -# Copyright (C) 2009 Free Software Foundation, Inc. +# Copyright (C) 2009, 2010 Free Software Foundation, Inc. # Contributed by Ian Lance Taylor . # This file is part of GCC. @@ -47,13 +47,13 @@ # the stack which we should not use. # void *__generic_morestack (size_t *frame_size, void *old_stack, -# size_t param_size); +# size_t param_size); -# The __morestack routine arranges for the caller to return to a stub -# on the new stack. The stub is responsible for restoring the old -# stack pointer and returning to the caller's caller. This calls -# __generic_releasestack to retrieve the old stack pointer and -# release the newly allocated stack. +# The __morestack routine has to arrange for the caller to return to a +# stub on the new stack. The stub is responsible for restoring the +# old stack pointer and returning to the caller's caller. This calls +# __generic_releasestack to retrieve the old stack pointer and release +# the newly allocated stack. # void *__generic_releasestack (size_t *available); @@ -71,10 +71,6 @@ # the call to __generic_morestack. That then returns to the caller of # the original caller. -# This entry point is for split-stack code which calls non-split-stack -# code. When the linker sees this case, it converts the call to -# __morestack to call __morestack_non_split instead. We just bump the -# requested stack space by 16K. # The amount of extra space we ask for. In general this has to be # enough for the dynamic loader to find a symbol and for a signal @@ -86,6 +82,12 @@ #define BACKOFF (1536) #endif + +# This entry point is for split-stack code which calls non-split-stack +# code. When the linker sees this case, it converts the call to +# __morestack to call __morestack_non_split instead. We just bump the +# requested stack space by 16K. + .global __morestack_non_split #ifdef __ELF__ @@ -106,6 +108,9 @@ __morestack_non_split: # __morestack_non_split falls through into __morestack. + +# The __morestack function. + .global __morestack #ifdef __ELF__ @@ -116,8 +121,12 @@ __morestack: .LFB1: .cfi_startproc + #ifndef __x86_64__ + +# The 32-bit __morestack function. + # We use a cleanup to restore the stack guard if an exception # is thrown through this code. #ifndef __PIC__ @@ -172,10 +181,10 @@ __morestack: subl 8(%ebp),%eax # The end of the stack space. addl $BACKOFF,%eax # Back off 512 bytes. +.LEHB0: # FIXME: The offset must match # TARGET_THREAD_SPLIT_STACK_OFFSET in # gcc/config/i386/linux.h. -.LEHB0: movl %eax,%gs:0x30 # Save the new stack boundary. call __morestack_unblock_signals @@ -204,12 +213,15 @@ __morestack: pushl %eax pushl %edx - call __morestack_block_signals - + # Push the arguments to __generic_releasestack now so that the + # stack is at a 16-byte boundary for + # __morestack_block_signals. pushl $0 # Where the available space is returned. leal 0(%esp),%eax # Push its address. push %eax + call __morestack_block_signals + call __generic_releasestack subl 4(%esp),%eax # Subtract available space. @@ -232,9 +244,11 @@ __morestack: pushl %eax # Push return value on old stack. pushl %edx + subl $8,%esp # Align stack to 16-byte boundary. call __morestack_unblock_signals + addl $8,%esp popl %edx # Restore return value. popl %eax @@ -272,6 +286,9 @@ __morestack: #else /* defined(__x86_64__) */ + +# The 64-bit __morestack function. + # We use a cleanup to restore the stack guard if an exception # is thrown through this code. #ifndef __PIC__ @@ -306,7 +323,7 @@ __morestack: # and %r9 may be used for parameters. We also preserve %rax # which the caller may use to hold %r10. - push %rax + pushq %rax pushq %rdi pushq %rsi pushq %rdx @@ -315,11 +332,13 @@ __morestack: pushq %r9 pushq %r11 + pushq $0 # For alignment. call __morestack_block_signals leaq -8(%rbp),%rdi # Address of new frame size. leaq 24(%rbp),%rsi # The caller's parameters. + addq $8,%rsp popq %rdx # The size of the parameters. call __generic_morestack @@ -329,10 +348,10 @@ __morestack: subq %r10,%rax # The end of the stack space. addq $BACKOFF,%rax # Back off 1024 bytes. +.LEHB0: # FIXME: The offset must match # TARGET_THREAD_SPLIT_STACK_OFFSET in # gcc/config/i386/linux64.h. -.LEHB0: movq %rax,%fs:0x70 # Save the new stack boundary. call __morestack_unblock_signals @@ -362,6 +381,7 @@ __morestack: call __morestack_block_signals + pushq $0 # For alignment. pushq $0 # Where the available space is returned. leaq 0(%rsp),%rdi # Pass its address. @@ -372,7 +392,7 @@ __morestack: .LEHE0: movq %rax,%fs:0x70 # Save the new stack boundary. - addq $8,%rsp # Remove value from stack. + addq $16,%rsp # Remove values from stack. # We need to restore the old stack pointer, which is in %rbp, # before we unblock signals. We also need to restore %rax and @@ -427,7 +447,10 @@ __morestack: .size __morestack, . - __morestack #endif - .globl __gcc_personality_v0 + +# The exception table. This tells the personality routine to execute +# the exception handler. + .section .gcc_except_table,"a",@progbits .align 4 .LLSDA1: @@ -442,6 +465,8 @@ __morestack: .uleb128 0 # action .LLSDACSE1: + + .globl __gcc_personality_v0 #ifdef __PIC__ # Build a position independent reference to the basic # personality function. @@ -461,6 +486,7 @@ DW.ref.__gcc_personality_v0: #endif #endif + # Initialize the stack test value when the program starts or when a # new thread starts. We don't know how large the main stack is, so we # guess conservatively. We might be able to use getrlimit here. @@ -507,6 +533,7 @@ __stack_split_initialize: .size __stack_split_initialize, . - __stack_split_initialize #endif + # Make __stack_split_initialize a high priority constructor. FIXME: # This is ELF specific.