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Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r--arch/arm64/mm/mmu.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index df377fbe464e..300e98e8cd63 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -416,9 +416,6 @@ void mark_rodata_ro(void)
{
unsigned long section_size;
- section_size = (unsigned long)_etext - (unsigned long)_text;
- update_mapping_prot(__pa_symbol(_text), (unsigned long)_text,
- section_size, PAGE_KERNEL_ROX);
/*
* mark .rodata as read only. Use __init_begin rather than __end_rodata
* to cover NOTES and EXCEPTION_TABLE.
@@ -451,6 +448,12 @@ static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end,
vm_area_add_early(vma);
}
+static int __init parse_rodata(char *arg)
+{
+ return strtobool(arg, &rodata_enabled);
+}
+early_param("rodata", parse_rodata);
+
/*
* Create fine-grained mappings for the kernel.
*/
@@ -458,7 +461,14 @@ static void __init map_kernel(pgd_t *pgd)
{
static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_init, vmlinux_data;
- map_kernel_segment(pgd, _text, _etext, PAGE_KERNEL_EXEC, &vmlinux_text);
+ /*
+ * External debuggers may need to write directly to the text
+ * mapping to install SW breakpoints. Allow this (only) when
+ * explicitly requested with rodata=off.
+ */
+ pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
+
+ map_kernel_segment(pgd, _text, _etext, text_prot, &vmlinux_text);
map_kernel_segment(pgd, __start_rodata, __init_begin, PAGE_KERNEL, &vmlinux_rodata);
map_kernel_segment(pgd, __init_begin, __init_end, PAGE_KERNEL_EXEC,
&vmlinux_init);