From 38f08ec0bd9bd39c578c2e9283a9aa00dc6bda15 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Fri, 2 Feb 2018 00:16:43 +0000 Subject: runtime: scan register backing store on ia64 On ia64, a separate stack is used for saving/restoring register frames, occupying the other end of the stack mapping. This must also be scanned for pointers into the heap. Reviewed-on: https://go-review.googlesource.com/85276 From-SVN: r257323 --- gcc/go/gofrontend/MERGE | 2 +- libgo/go/runtime/runtime2.go | 4 ++++ libgo/runtime/proc.c | 10 ++++++++++ libgo/runtime/runtime.h | 17 +++++++++++++++++ libgo/runtime/stack.c | 12 ++++++++++++ 5 files changed, 44 insertions(+), 1 deletion(-) diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index cc64fad..46bdc3c 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -e148068360699f24118950b728f23a5c98e1f85e +5e8a91bf239c253d7b5c84bd2c1dd3ecb18980e9 The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/libgo/go/runtime/runtime2.go b/libgo/go/runtime/runtime2.go index 543086d..0299d5a 100644 --- a/libgo/go/runtime/runtime2.go +++ b/libgo/go/runtime/runtime2.go @@ -409,11 +409,15 @@ type g struct { // gcnextsegment: unused // gcnextsp: current SP while executing a syscall // gcinitialsp: g0: top of stack; others: start of stack memory + // gcnextsp2: current secondary stack pointer (if present) + // gcinitialsp2: start of secondary stack (if present) gcstack uintptr gcstacksize uintptr gcnextsegment uintptr gcnextsp uintptr gcinitialsp unsafe.Pointer + gcnextsp2 uintptr + gcinitialsp2 unsafe.Pointer // gcregs holds the register values while executing a syscall. // This is set by getcontext and scanned by the garbage collector. diff --git a/libgo/runtime/proc.c b/libgo/runtime/proc.c index 556d86f..12c055d 100644 --- a/libgo/runtime/proc.c +++ b/libgo/runtime/proc.c @@ -308,6 +308,7 @@ runtime_mcall(FuncVal *fv) // Ensure that all registers are on the stack for the garbage // collector. __builtin_unwind_init(); + flush_registers_to_secondary_stack(); gp = g; mp = gp->m; @@ -322,6 +323,7 @@ runtime_mcall(FuncVal *fv) // We have to point to an address on the stack that is // below the saved registers. gp->gcnextsp = (uintptr)(&afterregs); + gp->gcnextsp2 = (uintptr)(secondary_stack_pointer()); #endif gp->fromgogo = false; getcontext(ucontext_arg(&gp->context[0])); @@ -500,6 +502,8 @@ runtime_mstart(void *arg) // is the top of the stack, not the bottom. gp->gcstacksize = 0; gp->gcnextsp = (uintptr)(&arg); + gp->gcinitialsp2 = secondary_stack_pointer(); + gp->gcnextsp2 = (uintptr)(gp->gcinitialsp2); #endif // Save the currently active context. This will return @@ -576,6 +580,8 @@ setGContext(void) gp->gcstack = 0; gp->gcstacksize = 0; gp->gcnextsp = (uintptr)(&val); + gp->gcinitialsp2 = secondary_stack_pointer(); + gp->gcnextsp2 = (uintptr)(gp->gcinitialsp2); #endif getcontext(ucontext_arg(&gp->context[0])); @@ -654,6 +660,7 @@ doentersyscall(uintptr pc, uintptr sp) void *v; g->gcnextsp = (uintptr)(&v); + g->gcnextsp2 = (uintptr)(secondary_stack_pointer()); } #endif @@ -694,6 +701,7 @@ doentersyscallblock(uintptr pc, uintptr sp) void *v; g->gcnextsp = (uintptr)(&v); + g->gcnextsp2 = (uintptr)(secondary_stack_pointer()); } #endif @@ -756,6 +764,7 @@ runtime_malg(bool allocatestack, bool signalstack, byte** ret_stack, uintptr* re *ret_stacksize = (uintptr)stacksize; newg->gcinitialsp = *ret_stack; newg->gcstacksize = (uintptr)stacksize; + newg->gcinitialsp2 = initial_secondary_stack_pointer(*ret_stack); #endif } return newg; @@ -807,6 +816,7 @@ resetNewG(G *newg, void **sp, uintptr *spsize) if(*spsize == 0) runtime_throw("bad spsize in resetNewG"); newg->gcnextsp = (uintptr)(*sp); + newg->gcnextsp2 = (uintptr)(newg->gcinitialsp2); #endif } diff --git a/libgo/runtime/runtime.h b/libgo/runtime/runtime.h index 28d550d..0fafe82 100644 --- a/libgo/runtime/runtime.h +++ b/libgo/runtime/runtime.h @@ -437,6 +437,23 @@ void runtime_check(void) // the stacks are allocated by the splitstack library. extern uintptr runtime_stacks_sys; +/* + * ia64's register file is spilled to a separate stack, the register backing + * store, on window overflow, and must also be scanned. This occupies the other + * end of the normal stack allocation, growing upwards. + * We also need to ensure all register windows are flushed to the backing + * store, as unlike SPARC, __builtin_unwind_init doesn't do this on ia64. + */ +#ifdef __ia64__ +# define secondary_stack_pointer() __builtin_ia64_bsp() +# define initial_secondary_stack_pointer(stack_alloc) (stack_alloc) +# define flush_registers_to_secondary_stack() __builtin_ia64_flushrs() +#else +# define secondary_stack_pointer() nil +# define initial_secondary_stack_pointer(stack_alloc) nil +# define flush_registers_to_secondary_stack() +#endif + struct backtrace_state; extern struct backtrace_state *__go_get_backtrace_state(void); extern _Bool __go_file_line(uintptr, int, String*, String*, intgo *); diff --git a/libgo/runtime/stack.c b/libgo/runtime/stack.c index 900ca64..a971e8f 100644 --- a/libgo/runtime/stack.c +++ b/libgo/runtime/stack.c @@ -34,6 +34,7 @@ void doscanstack(G *gp, void* gcw) { // Save registers on the stack, so that if we are scanning our // own stack we will see them. __builtin_unwind_init(); + flush_registers_to_secondary_stack(); doscanstack1(gp, gcw); } @@ -82,21 +83,32 @@ static void doscanstack1(G *gp, void *gcw) { #else byte* bottom; byte* top; + byte* nextsp2; + byte* initialsp2; if(gp == runtime_g()) { // Scanning our own stack. bottom = (byte*)&gp; + nextsp2 = secondary_stack_pointer(); } else { // Scanning another goroutine's stack. // The goroutine is usually asleep (the world is stopped). bottom = (void*)gp->gcnextsp; if(bottom == nil) return; + nextsp2 = (void*)gp->gcnextsp2; } top = (byte*)(void*)(gp->gcinitialsp) + gp->gcstacksize; if(top > bottom) scanstackblock(bottom, (uintptr)(top - bottom), gcw); else scanstackblock(top, (uintptr)(bottom - top), gcw); + if (nextsp2 != nil) { + initialsp2 = (byte*)(void*)(gp->gcinitialsp2); + if(initialsp2 > nextsp2) + scanstackblock(nextsp2, (uintptr)(initialsp2 - nextsp2), gcw); + else + scanstackblock(initialsp2, (uintptr)(nextsp2 - initialsp2), gcw); + } #endif } -- cgit v1.1