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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-14 23:17:19 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-14 23:17:19 +0300
commitb2c91128212a4c1a36bd3085191bff21a34324be (patch)
tree75d4a67a8fe15c947941f5a347189a8701eba76b /arch/parisc/mm
parentca4b40629f4edd3a961bedcd118e3ad05439ec71 (diff)
parent4e617c86ba9be5211643e53f5f69d1195c956d68 (diff)
downloadlinux-b2c91128212a4c1a36bd3085191bff21a34324be.tar.xz
Merge branch 'parisc-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull more parisc updates from Helge Deller: "Two small enhancements, which I didn't included in the last pull request because I wanted to keep them a few more days in for-next before sending upstream: - Replace the ldcw barrier instruction by a nop instruction in the CAS code on uniprocessor machines. - Map variables read-only after init (enable ro_after_init feature)" * 'parisc-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Use __ro_after_init in init.c parisc: Use __ro_after_init in unwind.c parisc: Use __ro_after_init in time.c parisc: Use __ro_after_init in processor.c parisc: Use __ro_after_init in process.c parisc: Use __ro_after_init in perf_images.h parisc: Use __ro_after_init in pci.c parisc: Use __ro_after_init in inventory.c parisc: Use __ro_after_init in head.S parisc: Use __ro_after_init in firmware.c parisc: Use __ro_after_init in drivers.c parisc: Use __ro_after_init in cache.c parisc: Enable the ro_after_init feature parisc: Drop LDCW barrier in CAS code when running UP
Diffstat (limited to 'arch/parisc/mm')
-rw-r--r--arch/parisc/mm/init.c75
1 files changed, 39 insertions, 36 deletions
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 11ec1f1221a6..ddca8287d43b 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -66,7 +66,7 @@ static struct resource pdcdata_resource = {
.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
};
-static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __read_mostly;
+static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
/* The following array is initialized from the firmware specific
* information retrieved in kernel/inventory.c.
@@ -345,16 +345,7 @@ static void __init setup_bootmem(void)
memblock_dump_all();
}
-static int __init parisc_text_address(unsigned long vaddr)
-{
- static unsigned long head_ptr __initdata;
-
- if (!head_ptr)
- head_ptr = PAGE_MASK & (unsigned long)
- dereference_function_descriptor(&parisc_kernel_start);
-
- return core_kernel_text(vaddr) || vaddr == head_ptr;
-}
+static bool kernel_set_to_readonly;
static void __init map_pages(unsigned long start_vaddr,
unsigned long start_paddr, unsigned long size,
@@ -372,10 +363,11 @@ static void __init map_pages(unsigned long start_vaddr,
unsigned long vaddr;
unsigned long ro_start;
unsigned long ro_end;
- unsigned long kernel_end;
+ unsigned long kernel_start, kernel_end;
ro_start = __pa((unsigned long)_text);
ro_end = __pa((unsigned long)&data_start);
+ kernel_start = __pa((unsigned long)&__init_begin);
kernel_end = __pa((unsigned long)&_end);
end_paddr = start_paddr + size;
@@ -438,26 +430,30 @@ static void __init map_pages(unsigned long start_vaddr,
pg_table = (pte_t *) __va(pg_table) + start_pte;
for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
pte_t pte;
-
- if (force)
- pte = __mk_pte(address, pgprot);
- else if (parisc_text_address(vaddr)) {
- pte = __mk_pte(address, PAGE_KERNEL_EXEC);
- if (address >= ro_start && address < kernel_end)
- pte = pte_mkhuge(pte);
+ pgprot_t prot;
+ bool huge = false;
+
+ if (force) {
+ prot = pgprot;
+ } else if (address < kernel_start || address >= kernel_end) {
+ /* outside kernel memory */
+ prot = PAGE_KERNEL;
+ } else if (!kernel_set_to_readonly) {
+ /* still initializing, allow writing to RO memory */
+ prot = PAGE_KERNEL_RWX;
+ huge = true;
+ } else if (address >= ro_start) {
+ /* Code (ro) and Data areas */
+ prot = (address < ro_end) ?
+ PAGE_KERNEL_EXEC : PAGE_KERNEL;
+ huge = true;
+ } else {
+ prot = PAGE_KERNEL;
}
- else
-#if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
- if (address >= ro_start && address < ro_end) {
- pte = __mk_pte(address, PAGE_KERNEL_EXEC);
+
+ pte = __mk_pte(address, prot);
+ if (huge)
pte = pte_mkhuge(pte);
- } else
-#endif
- {
- pte = __mk_pte(address, pgprot);
- if (address >= ro_start && address < kernel_end)
- pte = pte_mkhuge(pte);
- }
if (address >= end_paddr)
break;
@@ -493,6 +489,12 @@ void __ref free_initmem(void)
{
unsigned long init_begin = (unsigned long)__init_begin;
unsigned long init_end = (unsigned long)__init_end;
+ unsigned long kernel_end = (unsigned long)&_end;
+
+ /* Remap kernel text and data, but do not touch init section yet. */
+ kernel_set_to_readonly = true;
+ map_pages(init_end, __pa(init_end), kernel_end - init_end,
+ PAGE_KERNEL, 0);
/* The init text pages are marked R-X. We have to
* flush the icache and mark them RW-
@@ -509,7 +511,7 @@ void __ref free_initmem(void)
PAGE_KERNEL, 1);
/* force the kernel to see the new TLB entries */
- __flush_tlb_range(0, init_begin, init_end);
+ __flush_tlb_range(0, init_begin, kernel_end);
/* finally dump all the instructions which were cached, since the
* pages are no-longer executable */
@@ -527,8 +529,9 @@ void mark_rodata_ro(void)
{
/* rodata memory was already mapped with KERNEL_RO access rights by
pagetable_init() and map_pages(). No need to do additional stuff here */
- printk (KERN_INFO "Write protecting the kernel read-only data: %luk\n",
- (unsigned long)(__end_rodata - __start_rodata) >> 10);
+ unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
+
+ pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
}
#endif
@@ -554,11 +557,11 @@ void mark_rodata_ro(void)
#define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
& ~(VM_MAP_OFFSET-1)))
-void *parisc_vmalloc_start __read_mostly;
+void *parisc_vmalloc_start __ro_after_init;
EXPORT_SYMBOL(parisc_vmalloc_start);
#ifdef CONFIG_PA11
-unsigned long pcxl_dma_start __read_mostly;
+unsigned long pcxl_dma_start __ro_after_init;
#endif
void __init mem_init(void)
@@ -632,7 +635,7 @@ void __init mem_init(void)
#endif
}
-unsigned long *empty_zero_page __read_mostly;
+unsigned long *empty_zero_page __ro_after_init;
EXPORT_SYMBOL(empty_zero_page);
/*