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[arch][x86][mmu] disable SMAP, add PGE feature

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32 and 64 bit:
- For now SMAP causes the mmu unit tests to fail, so disable.
- Make sure CR4.PGE is set if present.
- Make sure the rest of the system knows that user aspaces are available
  on 32bit.
This commit is contained in:
Travis Geiselbrecht
2025-04-08 23:46:18 -07:00
parent 80a08c177d
commit bc01491bc9
2 changed files with 20 additions and 5 deletions
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14
arch/x86/32/mmu.c
View File

@@ -12,6 +12,7 @@
#include <arch/arch_ops.h>
#include <arch/mmu.h>
#include <arch/x86.h>
#include <arch/x86/feature.h>
#include <arch/x86/mmu.h>
#include <assert.h>
#include <kernel/vm.h>
@@ -411,7 +412,7 @@ int arch_mmu_map(arch_aspace_t * const aspace, const vaddr_t vaddr, const paddr_
bool arch_mmu_supports_nx_mappings(void) { return false; }
bool arch_mmu_supports_ns_mappings(void) { return false; }
bool arch_mmu_supports_user_aspaces(void) { return false; }
bool arch_mmu_supports_user_aspaces(void) { return true; }
/* called once per cpu as it is brought up */
void x86_mmu_early_init_percpu(void) {
@@ -419,6 +420,17 @@ void x86_mmu_early_init_percpu(void) {
uint32_t cr0 = x86_get_cr0();
cr0 |= X86_CR0_WP;
x86_set_cr0(cr0);
/* Set some mmu control bits in CR4 */
uint32_t cr4 = x86_get_cr4();
if (x86_feature_test(X86_FEATURE_PGE))
cr4 |= X86_CR4_PGE;
if (x86_feature_test(X86_FEATURE_SMEP))
cr4 |= X86_CR4_SMEP;
/* TODO: enable SMAP when the rest of the system is ready for it */
//if (x86_feature_test(X86_FEATURE_SMAP))
// cr4 |= X86_CR4_SMAP;
x86_set_cr4(cr4);
}
void x86_mmu_early_init(void) {

11
arch/x86/64/mmu.c
View File

@@ -632,12 +632,15 @@ void x86_mmu_early_init_percpu(void) {
cr0 |= X86_CR0_WP;
x86_set_cr0(cr0);
/* Setting the SMEP & SMAP bit in CR4 */
uint64_t cr4 = x86_get_cr4();
/* Set some mmu control bits in CR4 */
uint32_t cr4 = x86_get_cr4();
if (x86_feature_test(X86_FEATURE_PGE))
cr4 |= X86_CR4_PGE;
if (x86_feature_test(X86_FEATURE_SMEP))
cr4 |= X86_CR4_SMEP;
if (x86_feature_test(X86_FEATURE_SMAP))
cr4 |= X86_CR4_SMAP;
/* TODO: enable SMAP when the rest of the system is ready for it */
//if (x86_feature_test(X86_FEATURE_SMAP))
// cr4 |= X86_CR4_SMAP;
x86_set_cr4(cr4);
/* Set NXE bit in MSR_EFER */