This is wrong, wrong, wrong.
1) The feature needs to be enabled on all processors, not just one. There's
a reason for that loop.
2) ValidKernelPte/Pde being marked global will make ALL kernel pages
global. This is probably not what you want.
Best regards,
Alex Ionescu
On Wed, Oct 14, 2015 at 12:33 PM, <sginsberg(a)svn.reactos.org> wrote:
> Author: sginsberg
> Date: Wed Oct 14 19:33:35 2015
> New Revision: 69528
>
> URL: http://svn.reactos.org/svn/reactos?rev=69528&view=rev
> Log:
> [NTOS]
> Add super-complicated handling of global pages to KeFlushCurrentTb (pretty
> much the same code which has been in HalpFlushTLB for the past ~6 years).
> This should be all that is required to make this feature work (everything
> else being in place already), and *seems* to work fine but is disabled
> under a switch until tested thoroughly.
>
> Global pages, an important optimization that allows for not flushing the
> whole x86 TLB every time CR3 is changed (typically on context switch to a
> new process, or during process attach/detach), relies on us doing extra
> work whenever we do alter a global page. This is likely where any bugs will
> have to be flushed out!
>
> Fixup Ki386EnableGlobalPage while we are at it -- disable/restore
> interrupts properly, and verify PGE-bit isn't set (nothing should have
> touched it before this routine, which is responsible for initializing it,
> so we shouldn't have to disable it). Fix, but disable, the CPU-sync spin as
> well as there should be no particular reason to do this for PGE-enabling
> during initialization (no other processor will be messing with PTEs at this
> stage, as compared to a call to KeFlushEntireTb).
>
> Everyone, repeat after me: Global pages are awesome!
>
> Modified:
> trunk/reactos/ntoskrnl/include/ntoskrnl.h
> trunk/reactos/ntoskrnl/ke/i386/cpu.c
> trunk/reactos/ntoskrnl/ke/i386/patpge.c
> trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c
>
> Modified: trunk/reactos/ntoskrnl/include/ntoskrnl.h
> URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/ntoskrnl.…
>
> ==============================================================================
> --- trunk/reactos/ntoskrnl/include/ntoskrnl.h [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/include/ntoskrnl.h [iso-8859-1] Wed Oct 14
> 19:33:35 2015
> @@ -98,6 +98,14 @@
> #define ASSERT NT_ASSERT
> #endif
>
> +
> +//
> +// Switch for enabling global page support
> +//
> +
> +//#define _GLOBAL_PAGES_ARE_AWESOME_
> +
> +
> /* Internal Headers */
> #include "internal/ntoskrnl.h"
> #include "config.h"
>
> Modified: trunk/reactos/ntoskrnl/ke/i386/cpu.c
> URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/i386/cpu.c?rev…
>
> ==============================================================================
> --- trunk/reactos/ntoskrnl/ke/i386/cpu.c [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/ke/i386/cpu.c [iso-8859-1] Wed Oct 14
> 19:33:35 2015
> @@ -878,8 +878,37 @@
> NTAPI
> KeFlushCurrentTb(VOID)
> {
> +
> +#if !defined(_GLOBAL_PAGES_ARE_AWESOME_)
> +
> /* Flush the TLB by resetting CR3 */
> __writecr3(__readcr3());
> +
> +#else
> +
> + /* Check if global pages are enabled */
> + if (KeFeatureBits & KF_GLOBAL_PAGE)
> + {
> + ULONG Cr4;
> +
> + /* Disable PGE */
> + Cr4 = __readcr4() & ~CR4_PGE;
> + __writecr4(Cr4);
> +
> + /* Flush everything */
> + __writecr3(__readcr3());
> +
> + /* Re-enable PGE */
> + __writecr4(Cr4 | CR4_PGE);
> + }
> + else
> + {
> + /* No global pages, resetting CR3 is enough */
> + __writecr3(__readcr3());
> + }
> +
> +#endif
> +
> }
>
> VOID
>
> Modified: trunk/reactos/ntoskrnl/ke/i386/patpge.c
> URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/i386/patpge.c?…
>
> ==============================================================================
> --- trunk/reactos/ntoskrnl/ke/i386/patpge.c [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/ke/i386/patpge.c [iso-8859-1] Wed Oct 14
> 19:33:35 2015
> @@ -17,40 +17,41 @@
>
> /* FUNCTIONS
> *****************************************************************/
>
> +INIT_SECTION
> ULONG_PTR
> NTAPI
> -INIT_FUNCTION
> Ki386EnableGlobalPage(IN ULONG_PTR Context)
> {
> - PLONG Count = (PLONG)Context;
> - ULONG Cr4, Cr3;
> + //PLONG Count;
> +#if defined(_GLOBAL_PAGES_ARE_AWESOME_)
> + ULONG Cr4;
> +#endif
> + BOOLEAN Enable;
>
> /* Disable interrupts */
> - _disable();
> -
> - /* Decrease CPU Count and loop until it's reached 0 */
> - do {InterlockedDecrement(Count);} while (!*Count);
> -
> - /* Now check if this is the Boot CPU */
> - if (!KeGetPcr()->Number)
> - {
> - /* It is.FIXME: Patch KeFlushCurrentTb */
> - }
> -
> - /* Now get CR4 and make sure PGE is masked out */
> + Enable = KeDisableInterrupts();
> +
> + /* Spin until other processors are ready */
> + //Count = (PLONG)Context;
> + //InterlockedDecrement(Count);
> + //while (*Count) YieldProcessor();
> +
> +#if defined(_GLOBAL_PAGES_ARE_AWESOME_)
> +
> + /* Get CR4 and ensure global pages are disabled */
> Cr4 = __readcr4();
> - __writecr4(Cr4 & ~CR4_PGE);
> -
> - /* Flush the TLB */
> - Cr3 = __readcr3();
> - __writecr3(Cr3);
> + ASSERT(!(Cr4 & CR4_PGE));
> +
> + /* Reset CR3 to flush the TLB */
> + __writecr3(__readcr3());
>
> /* Now enable PGE */
> - DPRINT("Global page support detected but not yet taken advantage
> of\n");
> - //__writecr4(Cr4 | CR4_PGE);
> -
> - /* Restore interrupts */
> - _enable();
> + __writecr4(Cr4 | CR4_PGE);
> +
> +#endif
> +
> + /* Restore interrupts and return */
> + KeRestoreInterrupts(Enable);
> return 0;
> }
>
>
> Modified: trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c
> URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/i386/init…
>
> ==============================================================================
> --- trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c [iso-8859-1] Wed Oct 14
> 19:33:35 2015
> @@ -249,15 +249,18 @@
> PMMPFN Pfn1;
> ULONG Flags;
>
> +#if defined(_GLOBAL_PAGES_ARE_AWESOME_)
> +
> /* Check for global bit */
> -#if 0
> if (KeFeatureBits & KF_GLOBAL_PAGE)
> {
> /* Set it on the template PTE and PDE */
> ValidKernelPte.u.Hard.Global = TRUE;
> ValidKernelPde.u.Hard.Global = TRUE;
> }
> +
> #endif
> +
> /* Now templates are ready */
> TempPte = ValidKernelPte;
> TempPde = ValidKernelPde;
>
>
>
This is checking for 8-byte alignment on x86, not 16-byte.
On Sun, Oct 11, 2015 at 2:51 PM, <pschweitzer(a)svn.reactos.org> wrote:
> if (!((ULONG_PTR)Buffers[i] & 0x2))
Best regards,
Alex Ionescu
Hi !
I don't think this commit constitutes a nice improvement for NTVDM at its
present status:
- having the precise list of the used headers in each .c file helped me in
knowing at a glance which functionalities a given .c needed,
- therefore enabling me to find better places where to put the functions and
possibly reduce the number of headers in the future (refactoring).
- This broke my numerous local changes regarding e.g. a modularization of
the CPU layer in NTVDM, video layer, ...
- Finally, stuffing indistinctively *all* the headers (including the private
ones like bios32p.h which purpose was to be used in the sources of one
module only) inside the PCH ntvdm.h, makes for example BIOS or DOS functions
visible inside hardware modules like ps2.h, which is completely illogical
when you try to modularize NTVDM at source level, by completely separating
hardware emulation from bios code and DOS emulation, etc... .
Therefore I will revert your commit tomorrow, while keeping a diff and put
it in a JIRA report.
Cheers,
Hermès.
________________________________________
[ros-diffs] [akhaldi] 69435: [NTVDM] Improve the PCH situation.
akhaldi at svn.reactos.org akhaldi at svn.reactos.org
Sat Oct 3 21:47:46 UTC 2015
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________________________________________
Author: akhaldi
Date: Sat Oct 3 21:47:46 2015
New Revision: 69435
URL: http://svn.reactos.org/svn/reactos?rev=69435&view=rev
Log:
[NTVDM] Improve the PCH situation.
On 28/09/2015 11:01, sginsberg(a)svn.reactos.org wrote:
> Author: sginsberg
> Date: Mon Sep 28 09:01:11 2015
> New Revision: 69393
>
> URL: http://svn.reactos.org/svn/reactos?rev=69393&view=rev
> Log:
> [NTOS] Fix the Ob wait system calls to only catch the exceptions that are expected to be raised by the Ke wait functions (and not potentially silently catching *any* exception and corrupting everything in the process). Also fixup some code logic. SEH Mega Fixup 1/???
>
> Modified:
> trunk/reactos/ntoskrnl/ob/obwait.c
>
> Modified: trunk/reactos/ntoskrnl/ob/obwait.c
> URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ob/obwait.c?rev=6…
> ==============================================================================
> --- trunk/reactos/ntoskrnl/ob/obwait.c [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/ob/obwait.c [iso-8859-1] Mon Sep 28 09:01:11 2015
> @@ -49,12 +49,12 @@
> IN BOOLEAN Alertable,
> IN PLARGE_INTEGER TimeOut OPTIONAL)
> {
> - PKWAIT_BLOCK WaitBlockArray = NULL;
> + PKWAIT_BLOCK WaitBlockArray;
> HANDLE Handles[MAXIMUM_WAIT_OBJECTS], KernelHandle;
> PVOID Objects[MAXIMUM_WAIT_OBJECTS];
> PVOID WaitObjects[MAXIMUM_WAIT_OBJECTS];
> - ULONG i = 0, ReferencedObjects = 0, j;
> - KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
> + ULONG i, ReferencedObjects, j;
> + KPROCESSOR_MODE PreviousMode;
> LARGE_INTEGER SafeTimeOut;
> BOOLEAN LockInUse;
> PHANDLE_TABLE_ENTRY HandleEntry;
> @@ -65,31 +65,26 @@
> NTSTATUS Status;
> PAGED_CODE();
>
> - /* Enter a critical region since we'll play with handles */
> - LockInUse = TRUE;
> - KeEnterCriticalRegion();
> -
> /* Check for valid Object Count */
> if ((ObjectCount > MAXIMUM_WAIT_OBJECTS) || !(ObjectCount))
> {
> /* Fail */
> - Status = STATUS_INVALID_PARAMETER_1;
> - goto Quickie;
> + return STATUS_INVALID_PARAMETER_1;
> }
>
> /* Check for valid Wait Type */
> if ((WaitType != WaitAll) && (WaitType != WaitAny))
> {
> /* Fail */
> - Status = STATUS_INVALID_PARAMETER_3;
> - goto Quickie;
> - }
> -
> - /* Enter SEH */
> - _SEH2_TRY
> - {
> - /* Check if the call came from user mode */
> - if (PreviousMode != KernelMode)
> + return STATUS_INVALID_PARAMETER_3;
> + }
> +
> + /* Enter SEH for user mode */
> + PreviousMode = ExGetPreviousMode();
> + if (PreviousMode != KernelMode)
> + {
> + /* Enter SEH */
> + _SEH2_TRY
No, this is plain wrong.
This is not because you're in kernel mode that the world is marvelous
and callers trustable.
A caller can pass you buggy address and you HAVE to wrap the
RtlCopyMemory in SEH to make sure that if a buggy address is passed, the
whole system isn't brought down (that's the whole purpose of the copy
after all!).
In case you have a doubt, just put some random:
Status = ZwWaitForMultipleObjects(2, (void **)0x42424242, WaitAll,
FALSE, NULL);
In a kernel component. In w2k3, you'll get Status = STATUS_ACCESS_VIOLATION
In ReactOS, with your changes: BSOD.
Please before doing random changes that you believe are right: do testing.
Alex already told you that.
Cheers,
--
Pierre Schweitzer <pierre at reactos.org>
System & Network Administrator
Senior Kernel Developer
ReactOS Deutschland e.V.
Hello,
Let me invite you to the monthly status meeting taking place last
Thursday of a month, 24th of September, 19:00 UTC, as usual.
IRC service will only be started shortly before the meeting. Your
participation passwords and server address will be emailed to you
shortly before the meeting starts, and they are going to be different
once again as they are not stored in any database. Hopefully it's not
much of inconvenience.
Please send agenda proposals to me before the meeting.
Regards,
Aleksey Bragin