Module: wine
Branch: master
Commit: 96f5968a651609aa22ba482d4b244e6599095735
URL: https://source.winehq.org/git/wine.git/?a=commit;h=96f5968a651609aa22ba482d…
Author: Rémi Bernon <rbernon(a)codeweavers.com>
Date: Wed Mar 31 12:23:37 2021 +0200
ntdll: Clear the first ~1MB of stack in signal_start_thread.
Instead of the whole stack.
Stack creation in virtual_alloc_thread_stack and RtlCreateUserStack, as
well as Windows rounding logic, enforce a minimum reserved size of 1MB.
There's a few guard and canary pages used on the bottom, plus a few more
on the top for initial context, and we have to keep a bit of space if we
ever need a stack while doing this, so we clear a bit less than 1MB to
be safe.
Signed-off-by: Rémi Bernon <rbernon(a)codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>
---
dlls/ntdll/signal_i386.c | 9 ++++-----
dlls/ntdll/signal_x86_64.c | 4 +---
2 files changed, 5 insertions(+), 8 deletions(-)
diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
index 635b8f4de81..59d9e1d0df9 100644
--- a/dlls/ntdll/signal_i386.c
+++ b/dlls/ntdll/signal_i386.c
@@ -504,13 +504,12 @@ USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer,
*/
__ASM_GLOBAL_FUNC( signal_start_thread,
"movl 4(%esp),%esi\n\t" /* context */
- "leal -12(%esi),%ecx\n\t"
+ "leal -12(%esi),%edi\n\t"
/* clear the thread stack */
- "andl $~0xfff,%ecx\n\t" /* round down to page size */
- "movl %fs:8,%edi\n\t" /* NtCurrentTeb()->Tib.StackLimit */
- "addl $0x1000,%edi\n\t"
+ "andl $~0xfff,%edi\n\t" /* round down to page size */
+ "movl $0xf0000,%ecx\n\t"
+ "subl %ecx,%edi\n\t"
"movl %edi,%esp\n\t"
- "subl %edi,%ecx\n\t"
"xorl %eax,%eax\n\t"
"shrl $2,%ecx\n\t"
"rep; stosl\n\t"
diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
index d88f7ae553a..c5a6666f4d2 100644
--- a/dlls/ntdll/signal_x86_64.c
+++ b/dlls/ntdll/signal_x86_64.c
@@ -1544,9 +1544,7 @@ __ASM_GLOBAL_FUNC( signal_start_thread,
"movq %rcx,%rbx\n\t" /* context */
/* clear the thread stack */
"andq $~0xfff,%rcx\n\t" /* round down to page size */
- "movq %gs:0x30,%rax\n\t"
- "movq 0x10(%rax),%rdi\n\t" /* NtCurrentTeb()->Tib.StackLimit */
- "addq $0x2000,%rdi\n\t"
+ "leaq -0xf0000(%rcx),%rdi\n\t"
"movq %rdi,%rsp\n\t"
"subq %rdi,%rcx\n\t"
"xorl %eax,%eax\n\t"