arch/arm64/mmu: arch_mem_map() should not overwrite existing mappings

Nicolas Pitre · carlescufi · commit bcef63331619 · 2023-03-13T09:15:37.000+01:00
If so this is most certainly a bug. arch_mem_unmap() should be
used before mapping the same area again.

Signed-off-by: Nicolas Pitre &lt;npitre@baylibre.com&gt;
diff --git a/arch/arm64/core/mmu.c b/arch/arm64/core/mmu.c
@@ -892,7 +892,7 @@ static void sync_domains(uintptr_t virt, size_t size)
 static int __arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flags)
 {
 	struct arm_mmu_ptables *ptables;
-	uint32_t entry_flags = MT_DEFAULT_SECURE_STATE | MT_P_RX_U_NA;
+	uint32_t entry_flags = MT_DEFAULT_SECURE_STATE | MT_P_RX_U_NA | MT_NO_OVERWRITE;
 
 	/* Always map in the kernel page tables */
 	ptables = &kernel_ptables;

Original file line number	Diff line number	Diff line change
`@@ -892,7 +892,7 @@ static void sync_domains(uintptr_t virt, size_t size)`
`892`	`892`	`static int __arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flags)`
`893`	`893`	`{`
`894`	`894`	`struct arm_mmu_ptables *ptables;`
`895`		`- uint32_t entry_flags = MT_DEFAULT_SECURE_STATE \| MT_P_RX_U_NA;`
	`895`	`+ uint32_t entry_flags = MT_DEFAULT_SECURE_STATE \| MT_P_RX_U_NA \| MT_NO_OVERWRITE;`
`896`	`896`
`897`	`897`	`/* Always map in the kernel page tables */`
`898`	`898`	`ptables = &kernel_ptables;`