X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Falpha-arch.c;h=066355f946eec8b3f1e91a9deb2cd2840920a502;hb=ea36d3d79b9dfe3598faca5e267efd5980b94d4a;hp=4053163ec18adc9c30ea82c311408ce3fe4daffc;hpb=358cad8bdef5c670e1bbe94c430bd27544995433;p=sbcl.git diff --git a/src/runtime/alpha-arch.c b/src/runtime/alpha-arch.c index 4053163..066355f 100644 --- a/src/runtime/alpha-arch.c +++ b/src/runtime/alpha-arch.c @@ -29,14 +29,17 @@ #include "interrupt.h" #include "interr.h" #include "breakpoint.h" +#include "monitor.h" extern char call_into_lisp_LRA[], call_into_lisp_end[]; extern size_t os_vm_page_size; #define BREAKPOINT_INST 0x80 -void arch_init(void) +void +arch_init(void) { - /* this must be called _after_ os_init, so we know what the page size is */ + /* This must be called _after_ os_init, so we know what the page + * size is. */ if(mmap((os_vm_address_t) call_into_lisp_LRA_page,os_vm_page_size, OS_VM_PROT_ALL,MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,-1,0) == (os_vm_address_t) -1) @@ -44,8 +47,8 @@ void arch_init(void) /* call_into_lisp_LRA is a collection of trampolines written in asm - * see alpha-assem.S. We copy it to call_into_lisp_LRA_page where - * VOPs and things can find it (I don't know why they can't find it - * where it was to start with). */ + * VOPs and things can find it. (I don't know why they can't find it + * where it was to start with.) */ bcopy(call_into_lisp_LRA,(void *)call_into_lisp_LRA_page,os_vm_page_size); os_flush_icache((os_vm_address_t)call_into_lisp_LRA_page, @@ -56,49 +59,53 @@ void arch_init(void) os_vm_address_t arch_get_bad_addr (int sig, siginfo_t *code, os_context_t *context) { - unsigned int badinst; + unsigned int badinst; - /* instructions are 32 bit quantities */ - unsigned int *pc ; - /* fprintf(stderr,"arch_get_bad_addr %d %p %p\n", - sig, code, context); */ - pc= (unsigned int *)(*os_context_pc_addr(context)); + /* Instructions are 32 bit quantities. */ + unsigned int *pc ; + /* fprintf(stderr,"arch_get_bad_addr %d %p %p\n", + sig, code, context); */ + pc= (unsigned int *)(*os_context_pc_addr(context)); - if(((unsigned long)pc) & 3) - return NULL; /* in what case would pc be unaligned? */ + if(((unsigned long)pc) & 3) { + return NULL; /* In what case would pc be unaligned?? */ + } - if( (pc < READ_ONLY_SPACE_START || - pc >= READ_ONLY_SPACE_START+READ_ONLY_SPACE_SIZE) && - (pc < current_dynamic_space || - pc >= current_dynamic_space + DYNAMIC_SPACE_SIZE)) - return NULL; + if( (pc < READ_ONLY_SPACE_START || + pc >= READ_ONLY_SPACE_START+READ_ONLY_SPACE_SIZE) && + (pc < current_dynamic_space || + pc >= current_dynamic_space + DYNAMIC_SPACE_SIZE)) + return NULL; - badinst = *pc; + badinst = *pc; - if(((badinst>>27)!=0x16) /* STL or STQ */ - && ((badinst>>27)!=0x13)) /* STS or STT */ - return NULL; /* Otherwise forget about address */ + if(((badinst>>27)!=0x16) /* STL or STQ */ + && ((badinst>>27)!=0x13)) /* STS or STT */ + return NULL; /* Otherwise forget about address. */ - return (os_vm_address_t) - (*os_context_register_addr(context,((badinst>>16)&0x1f)) - +(badinst&0xffff)); + return (os_vm_address_t) + (*os_context_register_addr(context,((badinst>>16)&0x1f)) + +(badinst&0xffff)); } -void arch_skip_instruction(os_context_t *context) +void +arch_skip_instruction(os_context_t *context) { - /* this may be complete rubbish, as (at least for traps) pc points - * _after_ the instruction that caused us to be here anyway + /* This may be complete rubbish, as (at least for traps) pc points + * _after_ the instruction that caused us to be here anyway. */ ((char*)*os_context_pc_addr(context)) +=4; } -unsigned char *arch_internal_error_arguments(os_context_t *context) +unsigned char * +arch_internal_error_arguments(os_context_t *context) { return (unsigned char *)(*os_context_pc_addr(context)+4); } -boolean arch_pseudo_atomic_atomic(os_context_t *context) +boolean +arch_pseudo_atomic_atomic(os_context_t *context) { - return ((*os_context_register_addr(context,reg_ALLOC)) & 1); + return ((*os_context_register_addr(context,reg_ALLOC)) & 1); } void arch_set_pseudo_atomic_interrupted(os_context_t *context) @@ -116,7 +123,7 @@ void arch_set_pseudo_atomic_interrupted(os_context_t *context) /* [1] This behaviour can be changed with osf_setsysinfo, but cmucl * didn't use that */ -#ifdef linux +#ifdef __linux__ *os_context_register_addr(context,reg_ALLOC) |= (1L<<63); #else *os_context_register_addr(context,reg_ALLOC) |= 2; @@ -129,7 +136,6 @@ unsigned long arch_install_breakpoint(void *pc) unsigned int *ptr = (unsigned int *)pc; unsigned long result = (unsigned long) *ptr; *ptr = BREAKPOINT_INST; - *(ptr+1)=trap_Breakpoint; os_flush_icache((os_vm_address_t)ptr, sizeof(unsigned long)); @@ -139,7 +145,7 @@ unsigned long arch_install_breakpoint(void *pc) void arch_remove_breakpoint(void *pc, unsigned long orig_inst) { /* was (unsigned int) but gcc complains. Changed to mirror - install_breakpoint above */ + * install_breakpoint() above */ unsigned long *ptr=(unsigned long *)pc; *ptr = orig_inst; os_flush_icache((os_vm_address_t)pc, sizeof(unsigned long)); @@ -149,16 +155,14 @@ static unsigned int *skipped_break_addr, displaced_after_inst, after_breakpoint; -/* Returns a PC value. Lisp code is all in the 32-bit-addressable - space,so we should be ok with an unsigned int */ - +/* This returns a PC value. Lisp code is all in the 32-bit-addressable + * space,so we should be ok with an unsigned int. */ unsigned int emulate_branch(os_context_t *context,unsigned long orig_inst) { int op = orig_inst >> 26; int reg_a = (orig_inst >> 21) & 0x1f; int reg_b = (orig_inst >> 16) & 0x1f; - int fn = orig_inst & 0xffff; int disp = (orig_inst&(1<<20)) ? orig_inst | (-1 << 21) : orig_inst&0x1fffff; int next_pc = *os_context_pc_addr(context); int branch = 0; /* was NULL; */ @@ -225,68 +229,101 @@ emulate_branch(os_context_t *context,unsigned long orig_inst) static sigset_t orig_sigmask; +/* Perform the instruction that we overwrote with a breakpoint. As we + * don't have a single-step facility, this means we have to: + * - put the instruction back + * - put a second breakpoint at the following instruction, + * set after_breakpoint and continue execution. + * + * When the second breakpoint is hit (very shortly thereafter, we hope) + * sigtrap_handler gets called again, but follows the AfterBreakpoint + * arm, which + * - puts a bpt back in the first breakpoint place (running across a + * breakpoint shouldn't cause it to be uninstalled) + * - replaces the second bpt with the instruction it was meant to be + * - carries on + * + * Clear? + */ + void arch_do_displaced_inst(os_context_t *context,unsigned int orig_inst) { + /* Apparent off-by-one errors ahoy. If you consult the Alpha ARM, + * it will tell you that after a BPT, the saved PC is the address + * of the instruction _after_ the instruction that caused the trap. + * + * However, we decremented PC by 4 before calling the Lisp-level + * handler that calls this routine (see alpha-arch.c line 322 and + * friends) so when we get to this point PC is actually pointing + * at the BPT instruction itself. This is good, because this is + * where we want to restart execution when we do that */ + unsigned int *pc=(unsigned int *)(*os_context_pc_addr(context)); unsigned int *next_pc; - unsigned int next_inst; int op = orig_inst >> 26;; - fprintf(stderr,"arch_do_displaced_inst depends on sigreturn, which is not implemented and will\nalways fail\n"); + orig_sigmask = *os_context_sigmask_addr(context); sigaddset_blockable(os_context_sigmask_addr(context)); - /* Figure out where the displaced inst is going */ - if(op == 0x1a || (op&0xf) == 0x30) /* branch...ugh */ - /* the cast to long is just to shut gcc up */ - next_pc = (unsigned int *)((long)emulate_branch(context,orig_inst)); - else - next_pc = pc+1; - /* Put the original instruction back. */ *pc = orig_inst; os_flush_icache((os_vm_address_t)pc, sizeof(unsigned long)); skipped_break_addr = pc; - /* set the after breakpoint */ + /* Figure out where we will end up after running the displaced + * instruction */ + if(op == 0x1a || (op&0xf) == 0x30) /* a branch */ + /* The cast to long is just to shut gcc up. */ + next_pc = (unsigned int *)((long)emulate_branch(context,orig_inst)); + else + next_pc = pc+1; + + /* Set the after breakpoint. */ displaced_after_inst = *next_pc; *next_pc = BREAKPOINT_INST; after_breakpoint=1; os_flush_icache((os_vm_address_t)next_pc, sizeof(unsigned long)); - - ldb_monitor("sigreturn is not implemented and just failed"); - sigreturn(context); } -#define AfterBreakpoint 100 - -static void sigill_handler(int signal, siginfo_t *siginfo, os_context_t *context) { - fake_foreign_function_call(context); - ldb_monitor(); -} - -static void sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *context) +static void +sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *context) { + unsigned int code; + /* Don't disallow recursive breakpoint traps. Otherwise, we can't */ /* use debugger breakpoints anywhere in here. */ - sigset_t *mask=(os_context_sigmask_addr(context)); - unsigned int code; - fprintf(stderr,"sigtrap_handler:signal %d context=%p ",signal,context); sigsetmask(mask); - /* this is different from how CMUCL does it. CMUCL used - * "call_pal PAL_gentrap", which doesn't do anything on Linux - * so screwed up our offsets in odd ways. We use "bpt" instead - */ - - /* probably we should - assert(*(unsigned int*)(*os_context_pc_addr(context)-4) == BREAKPOINT_INST) - but I've not decided a good way to handle it if it turns out not to be - */ + /* this is different from how CMUCL does it. CMUCL used "call_pal + * PAL_gentrap", which doesn't do anything on Linux (unless NL0 + * contains certain specific values). We use "bugchk" instead. + * It's (for our purposes) just the same as bpt but has a + * different opcode so we can test whether we're dealing with a + * breakpoint or a "system service" */ + + if((*(unsigned int*)(*os_context_pc_addr(context)-4))== BREAKPOINT_INST) { + if(after_breakpoint) { + /* see comments above arch_do_displaced_inst. This is where + * we reinsert the breakpoint that we removed earlier */ + + *os_context_pc_addr(context) -=4; + *skipped_break_addr = BREAKPOINT_INST; + os_flush_icache((os_vm_address_t)skipped_break_addr, + sizeof(unsigned long)); + skipped_break_addr = NULL; + *(unsigned int *)*os_context_pc_addr(context) = + displaced_after_inst; + os_flush_icache((os_vm_address_t)*os_context_pc_addr(context), sizeof(unsigned long)); + *os_context_sigmask_addr(context)= orig_sigmask; + after_breakpoint=0; /* false */ + return; + } else + code = trap_Breakpoint; + } else + /* a "system service" */ code=*((u32 *)(*os_context_pc_addr(context))); - fprintf(stderr,"pc=%lx code=%d, inst=%x\n", - *os_context_pc_addr(context), code, - *(unsigned int*)(*os_context_pc_addr(context)-4)); + switch (code) { case trap_PendingInterrupt: arch_skip_instruction(context); @@ -302,43 +339,33 @@ static void sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *contex interrupt_internal_error(signal, siginfo, context, code==trap_Cerror); break; - case trap_Breakpoint: + case trap_Breakpoint: /* call lisp-level handler */ *os_context_pc_addr(context) -=4; handle_breakpoint(signal, siginfo, context); break; case trap_FunctionEndBreakpoint: *os_context_pc_addr(context) -=4; - *os_context_pc_addr(context) = (int)handle_function_end_breakpoint(signal, siginfo, context); - break; - - case AfterBreakpoint: - *os_context_pc_addr(context) -=4; - *skipped_break_addr = BREAKPOINT_INST; - os_flush_icache((os_vm_address_t)skipped_break_addr, - sizeof(unsigned long)); - skipped_break_addr = NULL; - *(unsigned int *)*os_context_pc_addr(context) = displaced_after_inst; - os_flush_icache((os_vm_address_t)*os_context_pc_addr(context), sizeof(unsigned long)); - *os_context_sigmask_addr(context)= orig_sigmask; - after_breakpoint=0; /* NULL; */ + *os_context_pc_addr(context) = + (int)handle_function_end_breakpoint(signal, siginfo, context); break; default: + fprintf(stderr, "unidetified breakpoint/trap %d\n",code); interrupt_handle_now(signal, siginfo, context); break; } } -#define FIXNUM_VALUE(lispobj) (((int)lispobj)>>2) - static void sigfpe_handler(int signal, int code, os_context_t *context) { + /* what should this contain? interesting question. If it really + * is empty, why don't we just ignore the signal? -dan 2001.08.10 + */ } void arch_install_interrupt_handlers() { - undoably_install_low_level_interrupt_handler(SIGILL, sigill_handler); undoably_install_low_level_interrupt_handler(SIGTRAP, sigtrap_handler); undoably_install_low_level_interrupt_handler(SIGFPE, sigfpe_handler); } @@ -385,13 +412,3 @@ lispobj funcall3(lispobj function, lispobj arg0, lispobj arg1, lispobj arg2) return call_into_lisp(function, args, 3); } - -/* This is apparently called by emulate_branch, but isn't defined. So */ -/* just do nothing and hope it works... */ - -void cacheflush(void) -{ - /* hoping probably isn't _actually_ enough. we should call_pal imb, - according to the arch ref manual - */ -}