| 811 |
|
// Enter nanokernel |
| 812 |
|
mtlr r3 |
| 813 |
|
blr |
| 814 |
+ |
|
| 815 |
+ |
|
| 816 |
+ |
/* |
| 817 |
+ |
* Define signal handlers with alternate stack initialization magic |
| 818 |
+ |
*/ |
| 819 |
+ |
|
| 820 |
+ |
#define SIG_STACK_SIZE 0x10000 |
| 821 |
+ |
|
| 822 |
+ |
ASM_MACRO_START do_define_signal_handler \ |
| 823 |
+ |
ASM_MACRO_ARG0_DEF /* name */ \ |
| 824 |
+ |
ASM_MACRO_ARG1_DEF /* stack */ \ |
| 825 |
+ |
ASM_MACRO_ARG2_DEF /* stack id */ \ |
| 826 |
+ |
ASM_MACRO_ARG3_DEF /* signal handler */ |
| 827 |
+ |
|
| 828 |
+ |
// Alternate stack lower base for this signal handler |
| 829 |
+ |
.lcomm ASM_MACRO_ARG1,SIG_STACK_SIZE,ASM_ALIGN_2(4) |
| 830 |
+ |
ASM_TYPE(ASM_MACRO_ARG1,@object) |
| 831 |
+ |
|
| 832 |
+ |
// Represents the current nest level for this signal handler |
| 833 |
+ |
// Note that in SheepShaver, SIGUSR2 signals are blocked while |
| 834 |
+ |
// handling other signals so, it's unlikely we ever get a nest |
| 835 |
+ |
// level greater than 1 |
| 836 |
+ |
.lcomm ASM_MACRO_ARG2,4,ASM_ALIGN_2(2) |
| 837 |
+ |
ASM_TYPE(ASM_MACRO_ARG2,@object) |
| 838 |
+ |
|
| 839 |
+ |
ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(ASM_MACRO_ARG0) |
| 840 |
+ |
C_SYMBOL_NAME(ASM_MACRO_ARG0): |
| 841 |
+ |
// Preserve args in scratch registers |
| 842 |
+ |
mflr r14 |
| 843 |
+ |
mr r15,r3 |
| 844 |
+ |
mr r16,r4 |
| 845 |
+ |
mr r17,r5 |
| 846 |
+ |
mr r18,r1 |
| 847 |
+ |
|
| 848 |
+ |
// Atomically increase stack_id |
| 849 |
+ |
lis r19,ASM_HA16(ASM_MACRO_ARG2) |
| 850 |
+ |
la r19,ASM_LO16(ASM_MACRO_ARG2,r19) |
| 851 |
+ |
li r4,1 |
| 852 |
+ |
mr r3,r19 |
| 853 |
+ |
bl C_SYMBOL_NAME(atomic_add) |
| 854 |
+ |
cmpwi r3,0 |
| 855 |
+ |
bne- 1f |
| 856 |
+ |
|
| 857 |
+ |
// ID was 0, we can use the local stack |
| 858 |
+ |
lis r9,ASM_HA16(ASM_MACRO_ARG1) |
| 859 |
+ |
lis r3,(SIG_STACK_SIZE>>16) |
| 860 |
+ |
la r9,ASM_LO16(ASM_MACRO_ARG1,r9) |
| 861 |
+ |
addi r3,r3,((SIG_STACK_SIZE&0xffff)-64) |
| 862 |
+ |
add r1,r9,r3 |
| 863 |
+ |
|
| 864 |
+ |
1: // Invoke signal handler |
| 865 |
+ |
stwu r1,-16(r1) |
| 866 |
+ |
mr r3,r15 |
| 867 |
+ |
mr r4,r16 |
| 868 |
+ |
mr r5,r17 |
| 869 |
+ |
bl C_SYMBOL_NAME(ASM_MACRO_ARG3) |
| 870 |
+ |
addi r1,r1,16 |
| 871 |
+ |
|
| 872 |
+ |
// Atomically decrease stack id |
| 873 |
+ |
mr r3,r19 |
| 874 |
+ |
li r4,-1 |
| 875 |
+ |
bl C_SYMBOL_NAME(atomic_add) |
| 876 |
+ |
|
| 877 |
+ |
// Restore kernel stack and return |
| 878 |
+ |
mtlr r14 |
| 879 |
+ |
mr r1,r18 |
| 880 |
+ |
blr |
| 881 |
+ |
ASM_MACRO_END |
| 882 |
+ |
|
| 883 |
+ |
#define DEFINE_SIGNAL_HANDLER(NAME) \ |
| 884 |
+ |
do_define_signal_handler \ |
| 885 |
+ |
NAME##_handler_init ASM_MACRO_ARG_SEP \ |
| 886 |
+ |
NAME##_stack ASM_MACRO_ARG_SEP \ |
| 887 |
+ |
NAME##_stack_id ASM_MACRO_ARG_SEP \ |
| 888 |
+ |
NAME##_handler |
| 889 |
+ |
|
| 890 |
+ |
DEFINE_SIGNAL_HANDLER(sigusr2) |
