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| author | Helge Deller <deller@gmx.de> | 2024-08-31 14:02:06 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2024-09-03 12:59:21 +0200 |
| commit | 213aa670153ed675a007c1f35c5db544b0fefc94 (patch) | |
| tree | 2a4fe3f4b812754ea9ab867e5b49d170c4b8c464 /arch/parisc | |
| parent | 5be63fc19fcaa4c236b307420483578a56986a37 (diff) | |
| download | lwn-213aa670153ed675a007c1f35c5db544b0fefc94.tar.gz lwn-213aa670153ed675a007c1f35c5db544b0fefc94.zip | |
parisc: Delay write-protection until mark_rodata_ro() call
Do not write-protect the kernel read-only and __ro_after_init sections
earlier than before mark_rodata_ro() is called. This fixes a boot issue on
parisc which is triggered by commit 91a1d97ef482 ("jump_label,module: Don't
alloc static_key_mod for __ro_after_init keys"). That commit may modify
static key contents in the __ro_after_init section at bootup, so this
section needs to be writable at least until mark_rodata_ro() is called.
Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Tested-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Link: https://lore.kernel.org/linux-parisc/096cad5aada514255cd7b0b9dbafc768@matoro.tk/#r
Fixes: 91a1d97ef482 ("jump_label,module: Don't alloc static_key_mod for __ro_after_init keys")
Cc: stable@vger.kernel.org # v6.10+
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/mm/init.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c index 34d91cb8b259..96970fa75e4a 100644 --- a/arch/parisc/mm/init.c +++ b/arch/parisc/mm/init.c @@ -459,7 +459,6 @@ void free_initmem(void) 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); @@ -493,11 +492,18 @@ void free_initmem(void) #ifdef CONFIG_STRICT_KERNEL_RWX 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 */ - unsigned long roai_size = __end_ro_after_init - __start_ro_after_init; + unsigned long start = (unsigned long) &__start_rodata; + unsigned long end = (unsigned long) &__end_rodata; + + pr_info("Write protecting the kernel read-only data: %luk\n", + (end - start) >> 10); + + kernel_set_to_readonly = true; + map_pages(start, __pa(start), end - start, PAGE_KERNEL, 0); - pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10); + /* force the kernel to see the new page table entries */ + flush_cache_all(); + flush_tlb_all(); } #endif |