Before this change we've treated Rbp as a CONTEXT_CONTROL register, but it is a CONTEXT_INTEGER register on windows (unlike ebp on i386, which is indeed a CONTEXT_CONTROL register on windows).
This caused issues with debuggers, specifically the Visual Studio 2022 Remote Debugging Server issues a SetThreadContext call with ContextFlags=CONTEXT_CONTROL, without Rbp set, which leads to Rbp getting erroneously zero'd.
Attached a simple test program [capture.c](/uploads/74698f4cd99246880250d6a139777603/capture.c), not sure if this should be part of the ntdll tests instead.
-- v2: ntdll, server: Treat Rbp as CONTEXT_INTEGER register.
From: Charlotte Pabst cpabst@codeweavers.com
--- dlls/dbghelp/tests/dbghelp.c | 2 +- dlls/ntdll/unix/signal_x86_64.c | 4 ++-- dlls/ntdll/unix/thread.c | 20 ++++++++++++++------ server/protocol.def | 4 ++-- server/trace.c | 2 +- tools/make_requests | 2 +- 6 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/dlls/dbghelp/tests/dbghelp.c b/dlls/dbghelp/tests/dbghelp.c index e9dcce300e9..9387804a1b2 100644 --- a/dlls/dbghelp/tests/dbghelp.c +++ b/dlls/dbghelp/tests/dbghelp.c @@ -100,7 +100,7 @@ static void test_stack_walk(void) } while (!count);
- ctx.ContextFlags = CONTEXT_CONTROL; + ctx.ContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER; ret = GetThreadContext(thread, &ctx); ok(ret, "got error %u\n", ret);
diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c index 058e3976ef1..6ec662b9850 100644 --- a/dlls/ntdll/unix/signal_x86_64.c +++ b/dlls/ntdll/unix/signal_x86_64.c @@ -1044,6 +1044,7 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context ) frame->rbx = context->Rbx; frame->rcx = context->Rcx; frame->rdx = context->Rdx; + frame->rbp = context->Rbp; frame->rsi = context->Rsi; frame->rdi = context->Rdi; frame->r8 = context->R8; @@ -1058,7 +1059,6 @@ NTSTATUS WINAPI NtSetContextThread( HANDLE handle, const CONTEXT *context ) if (flags & CONTEXT_CONTROL) { frame->rsp = context->Rsp; - frame->rbp = context->Rbp; frame->rip = context->Rip; frame->eflags = context->EFlags; } @@ -1109,6 +1109,7 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context ) context->Rbx = frame->rbx; context->Rcx = frame->rcx; context->Rdx = frame->rdx; + context->Rbp = frame->rbp; context->Rsi = frame->rsi; context->Rdi = frame->rdi; context->R8 = frame->r8; @@ -1124,7 +1125,6 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context ) if (needed_flags & CONTEXT_CONTROL) { context->Rsp = frame->rsp; - context->Rbp = frame->rbp; context->Rip = frame->rip; context->EFlags = frame->eflags; context->SegCs = cs64_sel; diff --git a/dlls/ntdll/unix/thread.c b/dlls/ntdll/unix/thread.c index 6a59fdb3cb3..ce6683e075f 100644 --- a/dlls/ntdll/unix/thread.c +++ b/dlls/ntdll/unix/thread.c @@ -351,12 +351,13 @@ static NTSTATUS context_to_server( struct context_data *to, USHORT to_machine, c if (flags & CONTEXT_I386_CONTROL) { to->flags |= SERVER_CTX_CONTROL; - to->ctl.x86_64_regs.rbp = from->Ebp; to->ctl.x86_64_regs.rsp = from->Esp; to->ctl.x86_64_regs.rip = from->Eip; to->ctl.x86_64_regs.cs = from->SegCs; to->ctl.x86_64_regs.ss = from->SegSs; to->ctl.x86_64_regs.flags = from->EFlags; + + to->integer.x86_64_regs.rbp = from->Ebp; } if (flags & CONTEXT_I386_INTEGER) { @@ -410,7 +411,6 @@ static NTSTATUS context_to_server( struct context_data *to, USHORT to_machine, c if (flags & CONTEXT_AMD64_CONTROL) { to->flags |= SERVER_CTX_CONTROL; - to->ctl.x86_64_regs.rbp = from->Rbp; to->ctl.x86_64_regs.rip = from->Rip; to->ctl.x86_64_regs.rsp = from->Rsp; to->ctl.x86_64_regs.cs = from->SegCs; @@ -424,6 +424,7 @@ static NTSTATUS context_to_server( struct context_data *to, USHORT to_machine, c to->integer.x86_64_regs.rcx = from->Rcx; to->integer.x86_64_regs.rdx = from->Rdx; to->integer.x86_64_regs.rbx = from->Rbx; + to->integer.x86_64_regs.rbp = from->Rbp; to->integer.x86_64_regs.rsi = from->Rsi; to->integer.x86_64_regs.rdi = from->Rdi; to->integer.x86_64_regs.r8 = from->R8; @@ -472,7 +473,6 @@ static NTSTATUS context_to_server( struct context_data *to, USHORT to_machine, c if (flags & CONTEXT_AMD64_CONTROL) { to->flags |= SERVER_CTX_CONTROL; - to->ctl.i386_regs.ebp = from->Rbp; to->ctl.i386_regs.eip = from->Rip; to->ctl.i386_regs.esp = from->Rsp; to->ctl.i386_regs.cs = from->SegCs; @@ -488,6 +488,8 @@ static NTSTATUS context_to_server( struct context_data *to, USHORT to_machine, c to->integer.i386_regs.ebx = from->Rbx; to->integer.i386_regs.esi = from->Rsi; to->integer.i386_regs.edi = from->Rdi; + + to->ctl.i386_regs.ebp = from->Rbp; } if (flags & CONTEXT_AMD64_SEGMENTS) { @@ -758,7 +760,6 @@ static NTSTATUS context_from_server( void *dst, const struct context_data *from, if ((from->flags & SERVER_CTX_CONTROL) && (to_flags & CONTEXT_I386_CONTROL)) { to->ContextFlags |= CONTEXT_I386_CONTROL; - to->Ebp = from->ctl.x86_64_regs.rbp; to->Esp = from->ctl.x86_64_regs.rsp; to->Eip = from->ctl.x86_64_regs.rip; to->SegCs = from->ctl.x86_64_regs.cs; @@ -775,6 +776,10 @@ static NTSTATUS context_from_server( void *dst, const struct context_data *from, to->Esi = from->integer.x86_64_regs.rsi; to->Edi = from->integer.x86_64_regs.rdi; } + if ((from->flags & SERVER_CTX_INTEGER) && (to_flags & CONTEXT_I386_CONTROL)) + { + to->Ebp = from->integer.x86_64_regs.rbp; + } if ((from->flags & SERVER_CTX_SEGMENTS) && (to_flags & CONTEXT_I386_SEGMENTS)) { to->ContextFlags |= CONTEXT_I386_SEGMENTS; @@ -820,7 +825,6 @@ static NTSTATUS context_from_server( void *dst, const struct context_data *from, if ((from->flags & SERVER_CTX_CONTROL) && (to_flags & CONTEXT_AMD64_CONTROL)) { to->ContextFlags |= CONTEXT_AMD64_CONTROL; - to->Rbp = from->ctl.x86_64_regs.rbp; to->Rip = from->ctl.x86_64_regs.rip; to->Rsp = from->ctl.x86_64_regs.rsp; to->SegCs = from->ctl.x86_64_regs.cs; @@ -834,6 +838,7 @@ static NTSTATUS context_from_server( void *dst, const struct context_data *from, to->Rcx = from->integer.x86_64_regs.rcx; to->Rdx = from->integer.x86_64_regs.rdx; to->Rbx = from->integer.x86_64_regs.rbx; + to->Rbp = from->integer.x86_64_regs.rbp; to->Rsi = from->integer.x86_64_regs.rsi; to->Rdi = from->integer.x86_64_regs.rdi; to->R8 = from->integer.x86_64_regs.r8; @@ -883,7 +888,6 @@ static NTSTATUS context_from_server( void *dst, const struct context_data *from, if ((from->flags & SERVER_CTX_CONTROL) && (to_flags & CONTEXT_AMD64_CONTROL)) { to->ContextFlags |= CONTEXT_AMD64_CONTROL; - to->Rbp = from->ctl.i386_regs.ebp; to->Rip = from->ctl.i386_regs.eip; to->Rsp = from->ctl.i386_regs.esp; to->SegCs = from->ctl.i386_regs.cs; @@ -900,6 +904,10 @@ static NTSTATUS context_from_server( void *dst, const struct context_data *from, to->Rsi = from->integer.i386_regs.esi; to->Rdi = from->integer.i386_regs.edi; } + if ((from->flags & SERVER_CTX_CONTROL) && (to_flags & CONTEXT_AMD64_INTEGER)) + { + to->Rbp = from->ctl.i386_regs.ebp; + } if ((from->flags & SERVER_CTX_SEGMENTS) && (to_flags & CONTEXT_AMD64_SEGMENTS)) { to->ContextFlags |= CONTEXT_AMD64_SEGMENTS; diff --git a/server/protocol.def b/server/protocol.def index dd9ace22b85..66d9f3e930b 100644 --- a/server/protocol.def +++ b/server/protocol.def @@ -143,7 +143,7 @@ struct context_data union { struct { unsigned int eip, ebp, esp, eflags, cs, ss; } i386_regs; - struct { unsigned __int64 rip, rbp, rsp; + struct { unsigned __int64 rip, rsp; unsigned int cs, ss, flags, __pad; } x86_64_regs; struct { unsigned int sp, lr, pc, cpsr; } arm_regs; struct { unsigned __int64 sp, pc, pstate; } arm64_regs; @@ -151,7 +151,7 @@ struct context_data union { struct { unsigned int eax, ebx, ecx, edx, esi, edi; } i386_regs; - struct { unsigned __int64 rax,rbx, rcx, rdx, rsi, rdi, + struct { unsigned __int64 rax, rbx, rcx, rdx, rbp, rsi, rdi, r8, r9, r10, r11, r12, r13, r14, r15; } x86_64_regs; struct { unsigned int r[13]; } arm_regs; struct { unsigned __int64 x[31]; } arm64_regs; diff --git a/server/trace.c b/server/trace.c index 77a91435b55..8f0f622fb48 100644 --- a/server/trace.c +++ b/server/trace.c @@ -754,7 +754,6 @@ static void dump_varargs_context( const char *prefix, data_size_t size ) if (ctx.flags & SERVER_CTX_CONTROL) { dump_uint64( ",rip=", &ctx.ctl.x86_64_regs.rip ); - dump_uint64( ",rbp=", &ctx.ctl.x86_64_regs.rbp ); dump_uint64( ",rsp=", &ctx.ctl.x86_64_regs.rsp ); fprintf( stderr, ",cs=%04x,ss=%04x,flags=%08x", ctx.ctl.x86_64_regs.cs, ctx.ctl.x86_64_regs.ss, ctx.ctl.x86_64_regs.flags ); @@ -765,6 +764,7 @@ static void dump_varargs_context( const char *prefix, data_size_t size ) dump_uint64( ",rbx=", &ctx.integer.x86_64_regs.rbx ); dump_uint64( ",rcx=", &ctx.integer.x86_64_regs.rcx ); dump_uint64( ",rdx=", &ctx.integer.x86_64_regs.rdx ); + dump_uint64( ",rbp=", &ctx.integer.x86_64_regs.rbp ); dump_uint64( ",rsi=", &ctx.integer.x86_64_regs.rsi ); dump_uint64( ",rdi=", &ctx.integer.x86_64_regs.rdi ); dump_uint64( ",r8=", &ctx.integer.x86_64_regs.r8 ); diff --git a/tools/make_requests b/tools/make_requests index d78595c1e78..f87664c9690 100755 --- a/tools/make_requests +++ b/tools/make_requests @@ -42,7 +42,7 @@ my %formats = "union apc_call" => [ 64, 8 ], "union apc_result" => [ 40, 8 ], "struct async_data" => [ 40, 8 ], - "struct context_data" => [ 1728, 8 ], + "struct context_data" => [ 1720, 8 ], "struct cursor_pos" => [ 24, 8 ], "union debug_event_data" => [ 160, 8 ], "struct filesystem_event" => [ 12, 4 ],
On Wed Jun 18 16:14:10 2025 +0000, Charlotte Pabst wrote:
changed this file in [version 2 of the diff](/wine/wine/-/merge_requests/8317/diffs?diff_id=186627&start_sha=0e3d21541423af9a24ba0423589e90de1c124318#14db54a17a35cba848dd64e46b554bf1cea32b93)
Thanks for the hint, removed those files from the MR.
On Sat Jun 14 01:42:02 2025 +0000, Jinoh Kang wrote:
If only `SERVER_CTX_CONTROL` is set, the server would ignore this rbp value since `SERVER_CTX_INTEGER` is NOT set. This goes on similarly with other changes. Perhaps we should move the translation logic to wineserver instead, so it can do the actual mapping itself.
FYI:
I'm aware of the problem, the core problem is the assumption that the i386 flags match the x64 flags 1:1, which probably goes beyond the translation logic in this function. To implement this properly, tests are probably necessary to verify how exactly windows deals with this.
I was quite unsure how to deal with this, so I've asked @julliard about it in private, and he told me it's probably okay to ignore this problem for now and the exact details might not matter that much. So I've written a "just forward whatever values we have" logic for now, and I think it's best to wait for his review here.
-
Charlotte Pabst -
Charlotte Pabst (＠CharlottePabst)