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x86 mem init: do not map identity mapping

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init_normal_area was mapping identity lookups (phys = virt) from 0,
leading to many undetected null pointer dereferences in init_pt (but
not in new process page tables leading to odd behaviour)

This also makes the code use the set_pt_large_page() function, cleaning
it up a bit

Change-Id: I22889031de26a7e48501b0eb4d453ca62e671835
This commit is contained in:
Dominique Martinet
2018-07-17 18:03:59 +09:00
committed by Dominique Martinet
parent fd429ecc5b
commit 3ce7763715
1 changed files with 10 additions and 13 deletions
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23
arch/x86_64/kernel/memory.c
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@ -170,24 +170,21 @@ static unsigned long setup_l3(struct page_table *pt,
static void init_normal_area(struct page_table *pt)
{
unsigned long map_start, map_end, phys, pt_phys;
int ident_index, virt_index;
void *virt;
map_start = ihk_mc_get_memory_address(IHK_MC_GMA_MAP_START, 0);
map_end = ihk_mc_get_memory_address(IHK_MC_GMA_MAP_END, 0);
virt = (void *)MAP_ST_START + map_start;
kprintf("map_start = %lx, map_end = %lx\n", map_start, map_end);
ident_index = map_start >> PTL4_SHIFT;
virt_index = (MAP_ST_START >> PTL4_SHIFT) & (PT_ENTRIES - 1);
kprintf("map_start = %lx, map_end = %lx, virt %lx\n",
map_start, map_end, virt);
memset(pt, 0, sizeof(struct page_table));
for (phys = (map_start & ~(PTL4_SIZE - 1)); phys < map_end;
phys += PTL4_SIZE) {
pt_phys = setup_l3(ihk_mc_alloc_pages(1, IHK_MC_AP_CRITICAL), phys,
map_start, map_end);
pt->entry[ident_index++] = pt_phys | PFL4_PDIR_ATTR;
pt->entry[virt_index++] = pt_phys | PFL4_PDIR_ATTR;
for (phys = map_start; phys < map_end; phys += LARGE_PAGE_SIZE) {
if (set_pt_large_page(pt, virt, phys, PTATTR_WRITABLE) != 0) {
kprintf("%s: error setting mapping for 0x%lx\n",
__func__, virt);
}
virt += LARGE_PAGE_SIZE;
}
}