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[NTOS] Allocate the trap frame on the stack by decreasing esp before modifying any members.

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While doing it after is a tiny optimization (no need to wait for esp to be ready) and would work with all real traps (which clear cli), it doesn't work with Zw calls that directly call KiSystemService with interrupts enabled. This caused random trap frame corruption when an interrupt fired after members of the trap frame have been set but before esp was adjusted. Should hopefully fix most random failures on real hardware and qemu.

svn path=/trunk/; revision=45598
This commit is contained in:
Timo Kreuzer 2010-02-15 20:16:15 +00:00
parent a7994c98a5
commit 690fd6eb6d
1 changed files with 25 additions and 25 deletions
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50
reactos/ntoskrnl/include/internal/i386/asmmacro.S
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@ -115,38 +115,41 @@ MACRO(KiEnterTrap, Flags)
endif
/* Make space for this frame */
sub esp, FrameSize
/* Save nonvolatile registers */
mov [esp - FrameSize + KTRAP_FRAME_EBP], ebp
mov [esp - FrameSize + KTRAP_FRAME_EBX], ebx
mov [esp - FrameSize + KTRAP_FRAME_ESI], esi
mov [esp - FrameSize + KTRAP_FRAME_EDI], edi
mov [esp + KTRAP_FRAME_EBP], ebp
mov [esp + KTRAP_FRAME_EBX], ebx
mov [esp + KTRAP_FRAME_ESI], esi
mov [esp + KTRAP_FRAME_EDI], edi
/* Save eax for system calls, for use by the C handler */
mov [esp - FrameSize + KTRAP_FRAME_EAX], eax
mov [esp + KTRAP_FRAME_EAX], eax
/* Does the caller want nonvolatiles only? */
if ((Flags AND KI_NONVOLATILES_ONLY) == 0)
/* Otherwise, save the volatiles as well */
mov [esp - FrameSize + KTRAP_FRAME_ECX], ecx
mov [esp - FrameSize + KTRAP_FRAME_EDX], edx
mov [esp + KTRAP_FRAME_ECX], ecx
mov [esp + KTRAP_FRAME_EDX], edx
endif
/* Save segment registers? */
if ((Flags AND KI_DONT_SAVE_SEGS) == 0)
/* Check for V86 mode */
test byte ptr [esp - FrameSize + KTRAP_FRAME_EFLAGS + 2], (EFLAGS_V86_MASK >> 16)
test byte ptr [esp + KTRAP_FRAME_EFLAGS + 2], (EFLAGS_V86_MASK >> 16)
jz not_v86_trap
/* Restore V8086 segments into Protected Mode segments */
mov eax, [esp - FrameSize + KTRAP_FRAME_V86_DS]
mov ecx, [esp - FrameSize + KTRAP_FRAME_V86_ES]
mov [esp - FrameSize + KTRAP_FRAME_DS], eax
mov [esp - FrameSize + KTRAP_FRAME_ES], ecx
mov eax, [esp - FrameSize + KTRAP_FRAME_V86_FS]
mov ecx, [esp - FrameSize + KTRAP_FRAME_V86_GS]
mov [esp - FrameSize + KTRAP_FRAME_FS], eax
mov [esp - FrameSize + KTRAP_FRAME_GS], ecx
mov eax, [esp + KTRAP_FRAME_V86_DS]
mov ecx, [esp + KTRAP_FRAME_V86_ES]
mov [esp + KTRAP_FRAME_DS], eax
mov [esp + KTRAP_FRAME_ES], ecx
mov eax, [esp + KTRAP_FRAME_V86_FS]
mov ecx, [esp + KTRAP_FRAME_V86_GS]
mov [esp + KTRAP_FRAME_FS], eax
mov [esp + KTRAP_FRAME_GS], ecx
jmp set_sane_segs
not_v86_trap:
@ -154,12 +157,12 @@ MACRO(KiEnterTrap, Flags)
/* Save segment selectors */
mov eax, ds
mov ecx, es
mov [esp - FrameSize + KTRAP_FRAME_DS], eax
mov [esp - FrameSize + KTRAP_FRAME_ES], ecx
mov [esp + KTRAP_FRAME_DS], eax
mov [esp + KTRAP_FRAME_ES], ecx
mov eax, fs
mov ecx, gs
mov [esp - FrameSize + KTRAP_FRAME_FS], eax
mov [esp - FrameSize + KTRAP_FRAME_GS], ecx
mov [esp + KTRAP_FRAME_FS], eax
mov [esp + KTRAP_FRAME_GS], ecx
endif
@ -176,15 +179,12 @@ set_sane_segs:
mov fs, ax
endif
/* Make space for this frame */
sub esp, FrameSize
/* Set parameter 1 (ECX) to point to the frame */
mov ecx, esp
/* Clear direction flag */
cld
/* Set parameter 1 (ECX) to point to the frame */
mov ecx, esp
ENDM
MACRO(TRAP_ENTRY, Trap, Flags)