limine: scale the maximum KASLR offset based on the address space size

This commit is contained in:
xvanc 2023-06-04 13:16:25 -05:00
parent 9274ee656e
commit 1f01ddfc6d
No known key found for this signature in database
3 changed files with 19 additions and 1 deletions

View File

@ -273,6 +273,19 @@ uint64_t paging_mode_higher_half(int paging_mode) {
}
}
int paging_mode_va_bits(int paging_mode) {
switch (paging_mode) {
case PAGING_MODE_RISCV_SV39:
return 39;
case PAGING_MODE_RISCV_SV48:
return 48;
case PAGING_MODE_RISCV_SV57:
return 57;
default:
panic(false, "paging_mode_va_bits: invalid mode");
}
}
int vmm_max_paging_mode(void)
{
static int max_level;

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@ -15,6 +15,8 @@
#define PAGING_MODE_X86_64_4LVL 0
#define PAGING_MODE_X86_64_5LVL 1
#define paging_mode_va_bits(mode) ((mode) ? 57 : 48)
static inline uint64_t paging_mode_higher_half(int paging_mode) {
if (paging_mode == PAGING_MODE_X86_64_5LVL) {
return 0xff00000000000000;
@ -89,6 +91,8 @@ void map_page(pagemap_t pagemap, uint64_t virt_addr, uint64_t phys_addr, uint64_
#define PAGING_MODE_RISCV_SV48 9
#define PAGING_MODE_RISCV_SV57 10
int paging_mode_va_bits(int paging_mode);
enum page_size {
Size4KiB,
Size2MiB,

View File

@ -194,7 +194,8 @@ static void **requests;
static void set_paging_mode(int paging_mode, bool kaslr) {
direct_map_offset = paging_mode_higher_half(paging_mode);
if (kaslr) {
direct_map_offset += (rand64() & ~((uint64_t)0x40000000 - 1)) & 0xfffffffffff;
uint64_t mask = ((uint64_t)1 << (paging_mode_va_bits(paging_mode) - 4)) - 1;
direct_map_offset += (rand64() & ~((uint64_t)0x40000000 - 1)) & mask;
}
}