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[NTOS]: Yet another fix for KiEnterInterruptTrap: Set correct DS/ES before touching the TrapFrame.

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[NTOS]: Make this operation an inline so any possible future code will not make this mistake twice.
Thanks to Physicus for the bug report.

svn path=/trunk/; revision=45381
This commit is contained in:
Sir Richard 2010-02-02 22:56:13 +00:00
parent d25de563d3
commit 66bdab40af
1 changed files with 30 additions and 29 deletions
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59
reactos/ntoskrnl/include/internal/trap_x.h
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@ -490,7 +490,31 @@ KiUserSystemCall(IN PKTRAP_FRAME TrapFrame)
: "r"(TrapFrame->SegCs)
);
}
VOID
FORCEINLINE
KiSetSaneSegments(IN PKTRAP_FRAME TrapFrame)
{
ULONG Ds, Es;
/*
* We really have to get a good DS/ES first before touching any data.
*
* These two reads will either go in a register (with optimizations ON) or
* a stack variable (which is on SS:ESP, guaranteed to be good/valid).
*
* Because the assembly is marked volatile, the order of instructions is
* as-is, otherwise the optimizer could simply get rid of our DS/ES.
*
*/
Ds = Ke386GetDs();
Es = Ke386GetEs();
Ke386SetDs(KGDT_R3_DATA | RPL_MASK);
Ke386SetEs(KGDT_R3_DATA | RPL_MASK);
TrapFrame->SegDs = Ds;
TrapFrame->SegEs = Es;
}
//
// Generic Exit Routine
//
@ -700,8 +724,6 @@ VOID
FORCEINLINE
KiEnterInterruptTrap(IN PKTRAP_FRAME TrapFrame)
{
ULONG Ds, Es;
/* Check for V86 mode, otherwise check for ring 3 code */
if (__builtin_expect(KiIsV8086TrapSafe(TrapFrame), 0))
{
@ -718,14 +740,9 @@ KiEnterInterruptTrap(IN PKTRAP_FRAME TrapFrame)
}
else if (__builtin_expect(KiIsUserTrapSafe(TrapFrame), 1)) /* Ring 3 is more common */
{
/* Save DS/ES and load correct values */
Es = Ke386GetEs();
Ds = Ke386GetDs();
TrapFrame->SegDs = Ds;
TrapFrame->SegEs = Es;
Ke386SetDs(KGDT_R3_DATA | RPL_MASK);
Ke386SetEs(KGDT_R3_DATA | RPL_MASK);
/* Switch to sane segments */
KiSetSaneSegments(TrapFrame);
/* Save FS/GS */
TrapFrame->SegFs = Ke386GetFs();
TrapFrame->SegGs = Ke386GetGs();
@ -760,24 +777,8 @@ VOID
FORCEINLINE
KiEnterTrap(IN PKTRAP_FRAME TrapFrame)
{
ULONG Ds, Es;
/*
* We really have to get a good DS/ES first before touching any data.
*
* These two reads will either go in a register (with optimizations ON) or
* a stack variable (which is on SS:ESP, guaranteed to be good/valid).
*
* Because the assembly is marked volatile, the order of instructions is
* as-is, otherwise the optimizer could simply get rid of our DS/ES.
*
*/
Ds = Ke386GetDs();
Es = Ke386GetEs();
Ke386SetDs(KGDT_R3_DATA | RPL_MASK);
Ke386SetEs(KGDT_R3_DATA | RPL_MASK);
TrapFrame->SegDs = Ds;
TrapFrame->SegEs = Es;
/* Switch to sane segments */
KiSetSaneSegments(TrapFrame);
/* Now we can save the other segments and then switch to the correct FS */
TrapFrame->SegFs = Ke386GetFs();