From ab4180ab19a5b2b096f137c3d56d771a70e159df Mon Sep 17 00:00:00 2001 From: John Hodge Date: Sun, 27 Sep 2009 12:13:27 +0800 Subject: [PATCH 1/1] Invalidated page that has just been marked COW --- Kernel/arch/x86/mm_virt.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c index be9a7ec8..a1feaec5 100644 --- a/Kernel/arch/x86/mm_virt.c +++ b/Kernel/arch/x86/mm_virt.c @@ -383,6 +383,7 @@ Uint MM_ClearUser() Uint MM_Clone() { Uint i, j; + Uint page = 0; Uint kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE; void *tmp; @@ -400,29 +401,31 @@ Uint MM_Clone() // Check if table is allocated if( !(gaPageDir[i] & PF_PRESENT) ) { gaTmpDir[i] = 0; + page += 1024; continue; } // Allocate new table gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7); - INVLPG( &gaTmpTable[i*1024] ); + INVLPG( &gaTmpTable[page] ); // Fill - for( j = 0; j < 1024; j ++ ) + for( j = 0; j < 1024; j ++, page++ ) { - if( !(gaPageTable[i*1024+j] & PF_PRESENT) ) { - gaTmpTable[i*1024+j] = 0; + if( !(gaPageTable[page] & PF_PRESENT) ) { + gaTmpTable[page] = 0; continue; } // Refrence old page - MM_RefPhys( gaPageTable[i*1024+j] & ~0xFFF ); + MM_RefPhys( gaPageTable[page] & ~0xFFF ); // Add to new table - if(gaPageTable[i*1024+j] & PF_WRITE) { - gaTmpTable[i*1024+j] = (gaPageTable[i*1024+j] & ~PF_WRITE) | PF_COW; - gaPageTable[i*1024+j] = (gaPageTable[i*1024+j] & ~PF_WRITE) | PF_COW; + if(gaPageTable[page] & PF_WRITE) { + gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW; + gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW; + INVLPG( page << 12 ); } else - gaTmpTable[i*1024+j] = gaPageTable[i*1024+j]; + gaTmpTable[page] = gaPageTable[page]; } } -- 2.20.1