Implemented signals for x86_64.

headers/posix/arch/x86_64/signal.h

@@ -12,35 +12,108 @@
 
 #if __x86_64__
 
-struct vregs {
-	unsigned long			rax;	/* gp regs */
-	unsigned long			rdx;
-	unsigned long			rcx;
-	unsigned long			rbx;
-	unsigned long			rsi;
-	unsigned long			rdi;
-	unsigned long			rbp;
-	unsigned long			rsp;
-
-	unsigned long			r8;	/* egp regs */
-	unsigned long			r9;
-	unsigned long			r10;
-	unsigned long			r11;
-	unsigned long			r12;
-	unsigned long			r13;
-	unsigned long			r14;
-	unsigned long			r15;
-
-	unsigned long			rip;
-
-/*TODO:	add
-*	Floatpoint
-*	MMX
-*	SSE
-*/
 
+struct fp_stack {
+	unsigned char		st0[10];
+	unsigned char		_reserved_42_47[6];
+	unsigned char		st1[10];
+	unsigned char		_reserved_58_63[6];
+	unsigned char		st2[10];
+	unsigned char		_reserved_74_79[6];
+	unsigned char		st3[10];
+	unsigned char		_reserved_90_95[6];
+	unsigned char		st4[10];
+	unsigned char		_reserved_106_111[6];
+	unsigned char		st5[10];
+	unsigned char		_reserved_122_127[6];
+	unsigned char		st6[10];
+	unsigned char		_reserved_138_143[6];
+	unsigned char		st7[10];
+	unsigned char		_reserved_154_159[6];
 };
 
+struct mmx_regs {
+	unsigned char		mm0[10];
+	unsigned char		_reserved_42_47[6];
+	unsigned char		mm1[10];
+	unsigned char		_reserved_58_63[6];
+	unsigned char		mm2[10];
+	unsigned char		_reserved_74_79[6];
+	unsigned char		mm3[10];
+	unsigned char		_reserved_90_95[6];
+	unsigned char		mm4[10];
+	unsigned char		_reserved_106_111[6];
+	unsigned char		mm5[10];
+	unsigned char		_reserved_122_127[6];
+	unsigned char		mm6[10];
+	unsigned char		_reserved_138_143[6];
+	unsigned char		mm7[10];
+	unsigned char		_reserved_154_159[6];
+};
+
+struct xmm_regs {
+	unsigned char		xmm0[16];
+	unsigned char		xmm1[16];
+	unsigned char		xmm2[16];
+	unsigned char		xmm3[16];
+	unsigned char		xmm4[16];
+	unsigned char		xmm5[16];
+	unsigned char		xmm6[16];
+	unsigned char		xmm7[16];
+	unsigned char		xmm8[16];
+	unsigned char		xmm9[16];
+	unsigned char		xmm10[16];
+	unsigned char		xmm11[16];
+	unsigned char		xmm12[16];
+	unsigned char		xmm13[16];
+	unsigned char		xmm14[16];
+	unsigned char		xmm15[16];
+};
+
+struct fpu_state {
+	unsigned short		control;
+	unsigned short		status;
+	unsigned short		tag;
+	unsigned short		opcode;
+	unsigned long		rip;
+	unsigned long		rdp;
+	unsigned int		mxcsr;
+	unsigned int		mscsr_mask;
+
+	union {
+		struct fp_stack	fp;
+		struct mmx_regs	mmx;
+	};
+
+	struct xmm_regs		xmm;
+	unsigned char		_reserved_416_511[96];
+};
+
+struct vregs {
+	unsigned long		rax;
+	unsigned long		rbx;
+	unsigned long		rcx;
+	unsigned long		rdx;
+	unsigned long		rdi;
+	unsigned long		rsi;
+	unsigned long		rbp;
+	unsigned long		r8;
+	unsigned long		r9;
+	unsigned long		r10;
+	unsigned long		r11;
+	unsigned long		r12;
+	unsigned long		r13;
+	unsigned long		r14;
+	unsigned long		r15;
+
+	unsigned long		rsp;
+	unsigned long		rip;
+	unsigned long		rflags;
+
+	struct fpu_state	fpu;
+};
+
+
 #endif /* __x86_64__ */
 
 #endif /* _ARCH_SIGNAL_H_ */

headers/private/kernel/arch/x86/arch_thread.h

@@ -25,8 +25,6 @@ struct iframe* x86_get_thread_user_iframe(Thread* thread);
 
 phys_addr_t x86_next_page_directory(Thread* from, Thread* to);
 void x86_initial_return_to_userland(Thread* thread, struct iframe* iframe);
-uint8* x86_get_signal_stack(Thread* thread, struct iframe* frame,
-	struct sigaction* action);
 
 void x86_restart_syscall(struct iframe* frame);
 void x86_set_tls_context(Thread* thread);

headers/private/system/arch/x86_64/arch_commpage_defs.h

@@ -11,7 +11,9 @@
 
 #define COMMPAGE_ENTRY_X86_MEMCPY	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 0)
 #define COMMPAGE_ENTRY_X86_MEMSET	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 1)
+#define COMMPAGE_ENTRY_X86_SIGNAL_HANDLER \
+									(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 2)
 
-#define ARCH_USER_COMMPAGE_ADDR (0xffffffffffff0000)
+#define ARCH_USER_COMMPAGE_ADDR		(0xffffffffffff0000)
 
 #endif	/* _SYSTEM_ARCH_x86_64_COMMPAGE_DEFS_H */

src/system/kernel/arch/x86/32/thread.cpp

@@ -107,6 +107,22 @@ x86_set_tls_context(Thread *thread)
 }
 
 
+static uint8*
+get_signal_stack(Thread* thread, struct iframe* frame, struct sigaction* action)
+{
+	// use the alternate signal stack if we should and can
+	if (thread->signal_stack_enabled
+		&& (action->sa_flags & SA_ONSTACK) != 0
+		&& (frame->user_sp < thread->signal_stack_base
+			|| frame->user_sp >= thread->signal_stack_base
+				+ thread->signal_stack_size)) {
+		return (uint8*)(thread->signal_stack_base + thread->signal_stack_size);
+	}
+
+	return (uint8*)frame->user_sp;
+}
+
+
 //	#pragma mark -
 
 
@@ -290,7 +306,7 @@ arch_setup_signal_frame(Thread* thread, struct sigaction* action,
 	signalFrameData->context.uc_mcontext.ebx = frame->bx;
 	x86_fnsave((void *)(&signalFrameData->context.uc_mcontext.xregs));
 
-	// fill in signalFrameData->context.uc_stack
+	// Fill in signalFrameData->context.uc_stack
 	signal_get_user_stack(frame->user_sp, &signalFrameData->context.uc_stack);
 
 	// store orig_eax/orig_edx in syscall_restart_return_value
@@ -299,7 +315,7 @@ arch_setup_signal_frame(Thread* thread, struct sigaction* action,
 
 	// get the stack to use -- that's either the current one or a special signal
 	// stack
-	uint8* userStack = x86_get_signal_stack(thread, frame, action);
+	uint8* userStack = get_signal_stack(thread, frame, action);
 
 	// copy the signal frame data onto the stack
 	userStack -= sizeof(*signalFrameData);

src/system/kernel/arch/x86/64/interrupts.S

@@ -337,8 +337,9 @@ FUNCTION(x86_64_syscall_entry):
 	// Get the system call table entry. Note I'm hardcoding the shift because
 	// sizeof(syscall_info) is 16 and scale factors of 16 aren't supported,
 	// so can't just do leaq kSyscallInfos(, %rax, SYSCALL_INFO_sizeof).
-	shlq	$4, %r14
-	leaq	kSyscallInfos(, %r14, 1), %rax
+	movq	%r14, %rax
+	shlq	$4, %rax
+	leaq	kSyscallInfos(, %rax, 1), %rax
 
 	// Check the number of call arguments, greater than 6 (6 * 8 = 48) requires
 	// a stack copy.
@@ -388,6 +389,10 @@ FUNCTION(x86_64_syscall_entry):
 
 	UPDATE_THREAD_KERNEL_TIME()
 
+	// If we've just restored a signal frame, use the IRET path.
+	cmpq	$SYSCALL_RESTORE_SIGNAL_FRAME, %r14
+	je		.Liret
+
 	// If the return address is not canonical, return using the IRET path.
 	// On Intel's implementation of SYSRET, the canonical address check for the
 	// return address is performed before the switch to user mode, so a fault

src/system/kernel/arch/x86/64/signals.cpp

@@ -15,12 +15,25 @@
 #include <elf.h>
 #include <smp.h>
 
-#include "syscall_numbers.h"
+
+extern "C" void _user_signal_handler(void);
+extern int _user_signal_handler_end;
 
 
 void
 x86_initialize_commpage_signal_handler()
 {
-	// TODO x86_64
+	void* handlerCode = (void*)&_user_signal_handler;
+	void* handlerCodeEnd = &_user_signal_handler_end;
+
+	// Copy the signal handler code to the commpage.
+	size_t len = (size_t)((addr_t)handlerCodeEnd - (addr_t)handlerCode);
+	fill_commpage_entry(COMMPAGE_ENTRY_X86_SIGNAL_HANDLER, handlerCode, len);
+
+	// Add symbol to the commpage image.
+	image_id image = get_commpage_image();
+	elf_add_memory_image_symbol(image, "commpage_signal_handler",
+		((addr_t*)USER_COMMPAGE_ADDR)[COMMPAGE_ENTRY_X86_SIGNAL_HANDLER],
+		len, B_SYMBOL_TYPE_TEXT);
 }
 

src/system/kernel/arch/x86/64/signals_asm.S

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2012, Alex Smith, alex@alex-smith.me.uk.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <asm_defs.h>
+
+#include "asm_offsets.h"
+#include "syscall_numbers.h"
+
+
+.text
+
+
+// Userspace signal handler wrapper, copied to the commpage.
+FUNCTION(_user_signal_handler):
+	push	%rbp
+	movq	%rsp, %rbp
+
+	// RDI points to the signal_frame_data structure, however we'll overwrite
+	// that with the function arguments, so move it somewhere else. We can use
+	// callee-save registers here without preserving them because the old value
+	// will be restored when the frame is restored.
+	movq	%rdi, %r12
+
+	// Check the handler type.
+	cmpb	$0, SIGNAL_FRAME_DATA_siginfo_handler(%r12)
+	jne		.Lsiginfo_handler
+
+.Lsimple_handler:
+	// Fetch other arguments (user data, vregs).
+	movq	SIGNAL_FRAME_DATA_user_data(%r12), %rsi
+	leaq	SIGNAL_FRAME_DATA_context + UCONTEXT_T_uc_mcontext(%r12), %rdx
+
+.Lcall_handler:
+	// Get the handler address and the signal number first argument.
+	movq	SIGNAL_FRAME_DATA_handler(%r12), %rax
+	movl	SIGNAL_FRAME_DATA_info + SIGINFO_T_si_signo(%r12), %edi
+
+	// Call the handler.
+	callq	*%rax
+
+	// Perform the restore_signal_frame() syscall, should not return.
+	movq	$SYSCALL_RESTORE_SIGNAL_FRAME, %rax
+	movq	%r12, %rdi
+	syscall
+
+.Lsiginfo_handler:
+	// Fetch other arguments (info pointer, context, user data).
+	leaq	SIGNAL_FRAME_DATA_info(%r12), %rsi
+	leaq	SIGNAL_FRAME_DATA_context(%r12), %rdx
+	movq	SIGNAL_FRAME_DATA_user_data(%r12), %rcx
+	jmp		.Lcall_handler
+FUNCTION_END(_user_signal_handler)
+SYMBOL(_user_signal_handler_end):

src/system/kernel/arch/x86/64/thread.cpp

@@ -12,7 +12,7 @@
 
 #include <string.h>
 
-#include <arch_cpu.h>
+#include <commpage.h>
 #include <cpu.h>
 #include <debug.h>
 #include <kernel.h>
@@ -57,6 +57,26 @@ x86_set_tls_context(Thread* thread)
 }
 
 
+static uint8*
+get_signal_stack(Thread* thread, iframe* frame, struct sigaction* action)
+{
+	// Use the alternate signal stack if we should and can.
+	if (thread->signal_stack_enabled
+			&& (action->sa_flags & SA_ONSTACK) != 0
+			&& (frame->user_sp < thread->signal_stack_base
+				|| frame->user_sp >= thread->signal_stack_base
+					+ thread->signal_stack_size)) {
+		return (uint8*)(thread->signal_stack_base + thread->signal_stack_size);
+	}
+
+	// We are going to use the stack that we are already on. We must not touch
+	// the red zone (128 byte area below the stack pointer, reserved for use
+	// by functions to store temporary data and guaranteed not to be modified
+	// by signal handlers).
+	return (uint8*)(frame->user_sp - 128);
+}
+
+
 //	#pragma mark -
 
 
@@ -203,8 +223,8 @@ arch_thread_enter_userspace(Thread* thread, addr_t entry, void* args1,
 	filled in:
 	- \c context.uc_stack: The stack currently used by the thread.
 	- \c context.uc_mcontext: The current userland state of the registers.
-	- \c syscall_restart_return_value: Architecture specific use. On x86 the
-		value of eax and edx which are overwritten by the syscall return value.
+	- \c syscall_restart_return_value: Architecture specific use. On x86_64 the
+		value of rax which is overwritten by the syscall return value.
 
 	Furthermore the function needs to set \c thread->user_signal_context to the
 	userland pointer to the \c ucontext_t on the user stack.
@@ -219,14 +239,116 @@ status_t
 arch_setup_signal_frame(Thread* thread, struct sigaction* action,
 	struct signal_frame_data* signalFrameData)
 {
-	panic("arch_setup_signal_frame: TODO\n");
-	return B_ERROR;
+	iframe* frame = x86_get_current_iframe();
+	if (!IFRAME_IS_USER(frame)) {
+		panic("arch_setup_signal_frame(): No user iframe!");
+		return B_BAD_VALUE;
+	}
+
+	// Store the register state.
+	signalFrameData->context.uc_mcontext.rax = frame->ax;
+	signalFrameData->context.uc_mcontext.rbx = frame->bx;
+	signalFrameData->context.uc_mcontext.rcx = frame->cx;
+	signalFrameData->context.uc_mcontext.rdx = frame->dx;
+	signalFrameData->context.uc_mcontext.rdi = frame->di;
+	signalFrameData->context.uc_mcontext.rsi = frame->si;
+	signalFrameData->context.uc_mcontext.rbp = frame->bp;
+	signalFrameData->context.uc_mcontext.r8 = frame->r8;
+	signalFrameData->context.uc_mcontext.r9 = frame->r9;
+	signalFrameData->context.uc_mcontext.r10 = frame->r10;
+	signalFrameData->context.uc_mcontext.r11 = frame->r11;
+	signalFrameData->context.uc_mcontext.r12 = frame->r12;
+	signalFrameData->context.uc_mcontext.r13 = frame->r13;
+	signalFrameData->context.uc_mcontext.r14 = frame->r14;
+	signalFrameData->context.uc_mcontext.r15 = frame->r15;
+	signalFrameData->context.uc_mcontext.rsp = frame->user_sp;
+	signalFrameData->context.uc_mcontext.rip = frame->ip;
+	signalFrameData->context.uc_mcontext.rflags = frame->flags;
+
+	// Store the FPU state. There appears to be a bug in GCC where the aligned
+	// attribute on a structure is being ignored when the structure is allocated
+	// on the stack, so even if the fpu_state struct has aligned(16) it may not
+	// get aligned correctly. Instead, use the current thread's FPU save area
+	// and then memcpy() to the frame structure.
+	x86_fxsave(thread->arch_info.fpu_state);
+	memcpy((void*)&signalFrameData->context.uc_mcontext.fpu,
+		thread->arch_info.fpu_state,
+		sizeof(signalFrameData->context.uc_mcontext.fpu));
+
+	// Fill in signalFrameData->context.uc_stack.
+	signal_get_user_stack(frame->user_sp, &signalFrameData->context.uc_stack);
+
+	// Store syscall_restart_return_value (TODO).
+	//signalFrameData->syscall_restart_return_value = frame->orig_rax;
+
+	// Get the stack to use and copy the frame data to it.
+	uint8* userStack = get_signal_stack(thread, frame, action);
+
+	userStack -= sizeof(*signalFrameData);
+	signal_frame_data* userSignalFrameData = (signal_frame_data*)userStack;
+
+	if (user_memcpy(userSignalFrameData, signalFrameData,
+			sizeof(*signalFrameData)) != B_OK) {
+		return B_BAD_ADDRESS;
+	}
+
+	// Copy a return address to the stack so that backtraces will be correct.
+	userStack -= sizeof(frame->ip);
+	if (user_memcpy(userStack, &frame->ip, sizeof(frame->ip)) != B_OK)
+		return B_BAD_ADDRESS;
+
+	// Update Thread::user_signal_context, now that everything seems to have
+	// gone fine.
+	thread->user_signal_context = &userSignalFrameData->context;
+
+	// Set up the iframe to execute the signal handler wrapper on our prepared
+	// stack. First argument points to the frame data.
+	frame->user_sp = (addr_t)userStack;
+	frame->ip = ((addr_t*)USER_COMMPAGE_ADDR)[COMMPAGE_ENTRY_X86_SIGNAL_HANDLER];
+	frame->di = (addr_t)userSignalFrameData;
+
+	return B_OK;
 }
 
 
 int64
 arch_restore_signal_frame(struct signal_frame_data* signalFrameData)
 {
-	panic("arch_restore_signal_frame: TODO\n");
-	return B_ERROR;
+	iframe* frame = x86_get_current_iframe();
+
+	// TODO
+	//frame->orig_rax = signalFrameData->syscall_restart_return_value;
+
+	frame->ax = signalFrameData->context.uc_mcontext.rax;
+	frame->bx = signalFrameData->context.uc_mcontext.rbx;
+	frame->cx = signalFrameData->context.uc_mcontext.rcx;
+	frame->dx = signalFrameData->context.uc_mcontext.rdx;
+	frame->di = signalFrameData->context.uc_mcontext.rdi;
+	frame->si = signalFrameData->context.uc_mcontext.rsi;
+	frame->bp = signalFrameData->context.uc_mcontext.rbp;
+	frame->r8 = signalFrameData->context.uc_mcontext.r8;
+	frame->r9 = signalFrameData->context.uc_mcontext.r9;
+	frame->r10 = signalFrameData->context.uc_mcontext.r10;
+	frame->r11 = signalFrameData->context.uc_mcontext.r11;
+	frame->r12 = signalFrameData->context.uc_mcontext.r12;
+	frame->r13 = signalFrameData->context.uc_mcontext.r13;
+	frame->r14 = signalFrameData->context.uc_mcontext.r14;
+	frame->r15 = signalFrameData->context.uc_mcontext.r15;
+	frame->user_sp = signalFrameData->context.uc_mcontext.rsp;
+	frame->ip = signalFrameData->context.uc_mcontext.rip;
+	frame->flags = (frame->flags & ~(uint64)X86_EFLAGS_USER_FLAGS)
+		| (signalFrameData->context.uc_mcontext.rflags & X86_EFLAGS_USER_FLAGS);
+
+	// Same as above, alignment may not be correct. Copy to thread and restore
+	// from there.
+	Thread* thread = thread_get_current_thread();
+	memcpy(thread->arch_info.fpu_state,
+		(void*)&signalFrameData->context.uc_mcontext.fpu,
+		sizeof(thread->arch_info.fpu_state));
+	x86_fxrstor(thread->arch_info.fpu_state);
+
+	// The syscall return code overwrites frame->ax with the return value of
+	// the syscall, need to return it here to ensure the correct value is
+	// restored.
+	return frame->ax;
 }

src/system/kernel/arch/x86/Jamfile

@@ -26,6 +26,7 @@ if $(TARGET_ARCH) = x86_64 {
 		interrupts.S
 		stubs.cpp
 		signals.cpp
+		signals_asm.S
 		syscalls.cpp
 		thread.cpp
 

src/system/kernel/arch/x86/arch_thread.cpp

@@ -172,23 +172,6 @@ x86_initial_return_to_userland(Thread* thread, iframe* frame)
 }
 
 
-uint8*
-x86_get_signal_stack(Thread* thread, struct iframe* frame,
-	struct sigaction* action)
-{
-	// use the alternate signal stack if we should and can
-	if (thread->signal_stack_enabled
-		&& (action->sa_flags & SA_ONSTACK) != 0
-		&& (frame->user_sp < thread->signal_stack_base
-			|| frame->user_sp >= thread->signal_stack_base
-				+ thread->signal_stack_size)) {
-		return (uint8*)(thread->signal_stack_base + thread->signal_stack_size);
-	}
-
-	return (uint8*)frame->user_sp;
-}
-
-
 //	#pragma mark -
 
 

src/system/kernel/arch/x86/asm_offsets.cpp

@@ -91,6 +91,7 @@ dummy()
 	DEFINE_OFFSET_MACRO(SIGNAL_FRAME_DATA, signal_frame_data, context);
 	DEFINE_OFFSET_MACRO(SIGNAL_FRAME_DATA, signal_frame_data, user_data);
 	DEFINE_OFFSET_MACRO(SIGNAL_FRAME_DATA, signal_frame_data, handler);
+	DEFINE_OFFSET_MACRO(SIGNAL_FRAME_DATA, signal_frame_data, siginfo_handler);
 
 	// struct ucontext_t
 	DEFINE_OFFSET_MACRO(UCONTEXT_T, __ucontext_t, uc_mcontext);

src/system/kernel/arch/x86/x86_signals.h

@@ -10,7 +10,9 @@
 
 
 void	x86_initialize_commpage_signal_handler();
+#ifndef __x86_64__
 addr_t	x86_get_user_signal_handler_wrapper(bool beosHandler);
+#endif
 
 
 #endif	// _KERNEL_ARCH_X86_SIGNALS_H