[PATCH v5 0/2] MR1182: ntdll: Add CFI unwind info to __wine_syscall_dispatcher (i386).
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. cc/ @florian-kuebler -- v5: ntdll: Add CFI unwind info to __wine_syscall_dispatcher (i386). ntdll: Move CFI helper macros out of signal_x86_64.c. https://gitlab.winehq.org/wine/wine/-/merge_requests/1182
From: Jinoh Kang <jinoh.kang.kr(a)gmail.com> --- dlls/ntdll/unix/dwarf.h | 12 ++++++++++++ dlls/ntdll/unix/signal_x86_64.c | 12 ------------ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/dlls/ntdll/unix/dwarf.h b/dlls/ntdll/unix/dwarf.h index cae7d6288ee..7a61662ba36 100644 --- a/dlls/ntdll/unix/dwarf.h +++ b/dlls/ntdll/unix/dwarf.h @@ -1010,4 +1010,16 @@ static void apply_frame_state( CONTEXT *context, struct frame_state *state, *context = new_context; } +#define __ASM_CFI_STR(...) #__VA_ARGS__ +#define __ASM_CFI_ESC(...) \ + __ASM_CFI(".cfi_escape " __ASM_CFI_STR(__VA_ARGS__) "\n\t") +#define __ASM_CFI_CFA_IS_AT1(base, offset) \ + __ASM_CFI_ESC(DW_CFA_def_cfa_expression, 0x03, DW_OP_ ## base, offset, DW_OP_deref) +#define __ASM_CFI_REG_IS_AT1(reg, base, offset) \ + __ASM_CFI_ESC(DW_CFA_expression, DW_REG_ ## reg, 0x02, DW_OP_ ## base, offset) +#define __ASM_CFI_CFA_IS_AT2(base, lo, hi) \ + __ASM_CFI_ESC(DW_CFA_def_cfa_expression, 0x04, DW_OP_ ## base, lo, hi, DW_OP_deref) +#define __ASM_CFI_REG_IS_AT2(reg, base, lo, hi) \ + __ASM_CFI_ESC(DW_CFA_expression, DW_REG_ ## reg, 0x03, DW_OP_ ## base, lo, hi) + #endif /* __NTDLL_DWARF_H */ diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c index 41f860ac4f4..1043e9bda2f 100644 --- a/dlls/ntdll/unix/signal_x86_64.c +++ b/dlls/ntdll/unix/signal_x86_64.c @@ -2535,18 +2535,6 @@ __ASM_GLOBAL_FUNC( signal_exit_thread, #define DW_REG_r15 0x0f #define DW_REG_rip 0x10 -#define __ASM_CFI_STR(...) #__VA_ARGS__ -#define __ASM_CFI_ESC(...) \ - __ASM_CFI(".cfi_escape " __ASM_CFI_STR(__VA_ARGS__) "\n\t") -#define __ASM_CFI_CFA_IS_AT1(base, offset) \ - __ASM_CFI_ESC(DW_CFA_def_cfa_expression, 0x03, DW_OP_ ## base, offset, DW_OP_deref) -#define __ASM_CFI_REG_IS_AT1(reg, base, offset) \ - __ASM_CFI_ESC(DW_CFA_expression, DW_REG_ ## reg, 0x02, DW_OP_ ## base, offset) -#define __ASM_CFI_CFA_IS_AT2(base, lo, hi) \ - __ASM_CFI_ESC(DW_CFA_def_cfa_expression, 0x04, DW_OP_ ## base, lo, hi, DW_OP_deref) -#define __ASM_CFI_REG_IS_AT2(reg, base, lo, hi) \ - __ASM_CFI_ESC(DW_CFA_expression, DW_REG_ ## reg, 0x03, DW_OP_ ## base, lo, hi) - /*********************************************************************** * __wine_syscall_dispatcher */ -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/1182
From: Jinoh Kang <jinoh.kang.kr(a)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/dwarf.h | 4 ++ dlls/ntdll/unix/signal_i386.c | 75 ++++++++++++++++++++++++++++++++++- 2 files changed, 78 insertions(+), 1 deletion(-) diff --git a/dlls/ntdll/unix/dwarf.h b/dlls/ntdll/unix/dwarf.h index 7a61662ba36..b32239e2fe1 100644 --- a/dlls/ntdll/unix/dwarf.h +++ b/dlls/ntdll/unix/dwarf.h @@ -233,6 +233,8 @@ #define DW_EH_PE_indirect 0x80 #define DW_EH_PE_omit 0xff +#ifndef NTDLL_DWARF_H_NO_UNWINDER + struct dwarf_eh_bases { void *tbase; @@ -1010,6 +1012,8 @@ static void apply_frame_state( CONTEXT *context, struct frame_state *state, *context = new_context; } +#endif /* NTDLL_DWARF_H_NO_UNWINDER */ + #define __ASM_CFI_STR(...) #__VA_ARGS__ #define __ASM_CFI_ESC(...) \ __ASM_CFI(".cfi_escape " __ASM_CFI_STR(__VA_ARGS__) "\n\t") diff --git a/dlls/ntdll/unix/signal_i386.c b/dlls/ntdll/unix/signal_i386.c index 2dfce706394..68367585948 100644 --- a/dlls/ntdll/unix/signal_i386.c +++ b/dlls/ntdll/unix/signal_i386.c @@ -58,6 +58,8 @@ #include "ddk/wdm.h" #include "wine/asm.h" #include "unix_private.h" +#define NTDLL_DWARF_H_NO_UNWINDER +#include "dwarf.h" #include "wine/debug.h" WINE_DEFAULT_DEBUG_CHANNEL(seh); @@ -2493,6 +2495,21 @@ __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 +2517,17 @@ __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 +2536,21 @@ __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 +2604,15 @@ __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 +2630,69 @@ __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" ) -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/1182
could be also handy to move it to wine/dwarf.h and share it with ntdll/unix.
I'll refactor it in a separate commit, since it'll span three header files (including the new one). -- https://gitlab.winehq.org/wine/wine/-/merge_requests/1182#note_12979
Rémi Bernon (@rbernon) commented about dlls/ntdll/unix/dwarf.h:
*context = new_context; }
+#define __ASM_CFI_STR(...) #__VA_ARGS__
I think it would make sense to keep the custom `DW_OP_` / `DW_REG_` defines here, as the macros are pretty much dependent on them. They would be guarded with arch ifdefs like the rest above. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/1182#note_13097
Rémi Bernon (@rbernon) commented about dlls/ntdll/unix/signal_i386.c:
#include "ddk/wdm.h" #include "wine/asm.h" #include "unix_private.h" +#define NTDLL_DWARF_H_NO_UNWINDER +#include "dwarf.h" To avoid having to move it later, I think it'd be better below the debug channel declaration.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/1182#note_13098
Rémi Bernon (@rbernon) commented about dlls/ntdll/unix/signal_i386.c:
"call *%ecx" )
+#define DW_OP_ecx DW_OP_breg1
So like said, these could go in dwarf.h. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/1182#note_13099
Looks good otherwise. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/1182#note_13100
participants (3)
-
Jinoh Kang -
Jinoh Kang (＠iamahuman)
-
Rémi Bernon