From: Jinoh Kang jinoh.kang.kr@gmail.com
This change is adding DWARF (CFI) unwind information to the hand-written assembly of the `__wine_syscall_dispatcher` function. This enables unwinding through the dispatcher from the Linux stack into (and through) the Windows stack.
The general idea is that the `syscall_frame` struct contains the content of the callee-save registers before the function call (in particular the stack pointer and the return address). At any point of the execution, we have a pointer into the `syscall_frame` in $ebx, $ecx, $ebp, or $esp.
For the CFI codes the general idea is that we are defining the computations of the callee-save registers based on the `syscall_frame` using DWARF’s `breg` instruction, rather than relative to CFA. --- dlls/ntdll/unix/signal_i386.c | 74 ++++++++++++++++++++++++++++++++++- 1 file changed, 73 insertions(+), 1 deletion(-)
diff --git a/dlls/ntdll/unix/signal_i386.c b/dlls/ntdll/unix/signal_i386.c index 2dfce706394..67efe7b544b 100644 --- a/dlls/ntdll/unix/signal_i386.c +++ b/dlls/ntdll/unix/signal_i386.c @@ -59,6 +59,7 @@ #include "wine/asm.h" #include "unix_private.h" #include "wine/debug.h" +#include "dwarf.h"
WINE_DEFAULT_DEBUG_CHANNEL(seh);
@@ -2493,6 +2494,21 @@ __ASM_GLOBAL_FUNC( signal_exit_thread, "call *%ecx" )
+#define DW_OP_ecx DW_OP_breg1 +#define DW_OP_ebx DW_OP_breg3 +#define DW_OP_esp DW_OP_breg4 +#define DW_OP_ebp DW_OP_breg5 + +#define DW_REG_eax 0x00 +#define DW_REG_ecx 0x01 +#define DW_REG_edx 0x02 +#define DW_REG_ebx 0x03 +#define DW_REG_esp 0x04 +#define DW_REG_ebp 0x05 +#define DW_REG_esi 0x06 +#define DW_REG_edi 0x07 +#define DW_REG_eip 0x08 + /*********************************************************************** * __wine_syscall_dispatcher */ @@ -2500,11 +2516,17 @@ __ASM_GLOBAL_FUNC( __wine_syscall_dispatcher, "movl %fs:0x1f8,%ecx\n\t" /* x86_thread_data()->syscall_frame */ "movw $0,0x02(%ecx)\n\t" /* frame->restore_flags */ "popl 0x08(%ecx)\n\t" /* frame->eip */ + __ASM_CFI(".cfi_adjust_cfa_offset -4\n\t") + __ASM_CFI_REG_IS_AT1(eip, ecx, 0x08) "pushfl\n\t" + __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t") "popl 0x04(%ecx)\n\t" /* frame->eflags */ + __ASM_CFI(".cfi_adjust_cfa_offset -4\n\t") ".globl " __ASM_NAME("__wine_syscall_dispatcher_prolog_end") "\n" __ASM_NAME("__wine_syscall_dispatcher_prolog_end") ":\n\t" "movl %esp,0x0c(%ecx)\n\t" /* frame->esp */ + __ASM_CFI_CFA_IS_AT1(ecx, 0x0c) + __ASM_CFI_REG_IS_AT1(esp, ecx, 0x0c) "movw %cs,0x10(%ecx)\n\t" "movw %ss,0x12(%ecx)\n\t" "movw %ds,0x14(%ecx)\n\t" @@ -2513,10 +2535,21 @@ __ASM_GLOBAL_FUNC( __wine_syscall_dispatcher, "movw %gs,0x1a(%ecx)\n\t" "movl %eax,0x1c(%ecx)\n\t" "movl %ebx,0x20(%ecx)\n\t" + __ASM_CFI_REG_IS_AT1(ebx, ecx, 0x20) "movl %edi,0x2c(%ecx)\n\t" + __ASM_CFI_REG_IS_AT1(edi, ecx, 0x2c) "movl %esi,0x30(%ecx)\n\t" + __ASM_CFI_REG_IS_AT1(esi, ecx, 0x30) "movl %ebp,0x34(%ecx)\n\t" + __ASM_CFI_REG_IS_AT1(ebp, ecx, 0x34) "leal 0x34(%ecx),%ebp\n\t" + __ASM_CFI_CFA_IS_AT1(ebp, 0x58) + __ASM_CFI_REG_IS_AT1(esp, ebp, 0x58) + __ASM_CFI_REG_IS_AT1(eip, ebp, 0x54) + __ASM_CFI_REG_IS_AT1(ebx, ebp, 0x6c) + __ASM_CFI_REG_IS_AT1(edi, ebp, 0x78) + __ASM_CFI_REG_IS_AT1(esi, ebp, 0x7c) + __ASM_CFI_REG_IS_AT1(ebp, ebp, 0x00) "leal 4(%esp),%esi\n\t" /* first argument */ "movl %eax,%ebx\n\t" "shrl $8,%ebx\n\t" @@ -2570,7 +2603,15 @@ __ASM_GLOBAL_FUNC( __wine_syscall_dispatcher, "rep; movsl\n\t" "call *(%eax,%edx,4)\n\t" "leal -0x34(%ebp),%esp\n" - "5:\tmovl 0(%esp),%ecx\n\t" /* frame->syscall_flags + (frame->restore_flags << 16) */ + "5:\t" + __ASM_CFI_CFA_IS_AT1(esp, 0x0c) + __ASM_CFI_REG_IS_AT1(esp, esp, 0x0c) + __ASM_CFI_REG_IS_AT1(eip, esp, 0x08) + __ASM_CFI_REG_IS_AT1(ebx, esp, 0x20) + __ASM_CFI_REG_IS_AT1(edi, esp, 0x2c) + __ASM_CFI_REG_IS_AT1(esi, esp, 0x30) + __ASM_CFI_REG_IS_AT1(ebp, esp, 0x34) + "movl 0(%esp),%ecx\n\t" /* frame->syscall_flags + (frame->restore_flags << 16) */ "testl $0x68 << 16,%ecx\n\t" /* CONTEXT_FLOATING_POINT | CONTEXT_EXTENDED_REGISTERS | CONTEXT_XSAVE */ "jz 3f\n\t" "testl $3,%ecx\n\t" /* SYSCALL_HAVE_XSAVE | SYSCALL_HAVE_XSAVEC */ @@ -2588,38 +2629,69 @@ __ASM_GLOBAL_FUNC( __wine_syscall_dispatcher, "2:\tfrstor 0x40(%esp)\n\t" "fwait\n" "3:\tmovl 0x2c(%esp),%edi\n\t" + __ASM_CFI(".cfi_remember_state\n\t") + __ASM_CFI(".cfi_same_value %edi\n\t") "movl 0x30(%esp),%esi\n\t" + __ASM_CFI(".cfi_same_value %esi\n\t") "movl 0x34(%esp),%ebp\n\t" + __ASM_CFI(".cfi_same_value %ebp\n\t") "testl $0x7 << 16,%ecx\n\t" /* CONTEXT_CONTROL | CONTEXT_SEGMENTS | CONTEXT_INTEGER */ "jnz 1f\n\t" "movl 0x20(%esp),%ebx\n\t" + __ASM_CFI(".cfi_remember_state\n\t") + __ASM_CFI(".cfi_same_value %ebx\n\t") "movl 0x08(%esp),%ecx\n\t" /* frame->eip */ + __ASM_CFI(".cfi_register %eip, %ecx\n\t") "movl 0x0c(%esp),%esp\n\t" /* frame->esp */ + __ASM_CFI(".cfi_same_value %esp\n\t") "jmpl *%ecx\n" + __ASM_CFI("\t.cfi_restore_state\n") "1:\ttestl $0x2 << 16,%ecx\n\t" /* CONTEXT_INTEGER */ "jz 1f\n\t" "movl 0x1c(%esp),%eax\n\t" "movl 0x24(%esp),%ecx\n\t" "movl 0x28(%esp),%edx\n" "1:\tmovl 0x0c(%esp),%ebx\n\t" /* frame->esp */ + __ASM_CFI(".cfi_register %esp, %ebx\n\t") "movw 0x12(%esp),%ss\n\t" "xchgl %ebx,%esp\n\t" + __ASM_CFI(".cfi_def_cfa %esp, 0\n\t") + __ASM_CFI(".cfi_same_value %esp\n\t") + __ASM_CFI_REG_IS_AT1(eip, ebx, 0x08) + __ASM_CFI_REG_IS_AT1(ebx, ebx, 0x20) "pushl 0x04(%ebx)\n\t" /* frame->eflags */ + __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t") "pushl 0x10(%ebx)\n\t" /* frame->cs */ + __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t") "pushl 0x08(%ebx)\n\t" /* frame->eip */ + __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t") + __ASM_CFI(".cfi_rel_offset %eip, 0\n\t") "pushl 0x14(%ebx)\n\t" /* frame->ds */ + __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t") "movw 0x16(%ebx),%es\n\t" "movw 0x18(%ebx),%fs\n\t" "movw 0x1a(%ebx),%gs\n\t" "movl 0x20(%ebx),%ebx\n\t" + __ASM_CFI(".cfi_same_value %ebx\n\t") "popl %ds\n\t" + __ASM_CFI(".cfi_adjust_cfa_offset -4\n\t") "iret\n" + __ASM_CFI("\t.cfi_restore_state\n") "6:\tmovl $0xc000000d,%eax\n\t" /* STATUS_INVALID_PARAMETER */ "jmp 5b\n\t" ".globl " __ASM_NAME("__wine_syscall_dispatcher_return") "\n" __ASM_NAME("__wine_syscall_dispatcher_return") ":\n\t" + __ASM_CFI(".cfi_remember_state\n\t") + __ASM_CFI(".cfi_def_cfa %esp, 4\n\t") + __ASM_CFI(".cfi_restore %esp\n\t") + __ASM_CFI(".cfi_restore %eip\n\t") + __ASM_CFI(".cfi_restore %ebx\n\t") + __ASM_CFI(".cfi_restore %edi\n\t") + __ASM_CFI(".cfi_restore %esi\n\t") + __ASM_CFI(".cfi_restore %ebp\n\t") "movl 8(%esp),%eax\n\t" "movl 4(%esp),%esp\n\t" + __ASM_CFI(".cfi_restore_state\n\t") "jmp 5b" )