From 0d8732e461d6b4dc2c625a69225f20e24da4dd79 Mon Sep 17 00:00:00 2001 From: Pasha Tatashin Date: Thu, 30 Sep 2021 14:31:02 +0000 Subject: [PATCH] arm64: kexec: flush image and lists during kexec load time Currently, during kexec load we are copying relocation function and flushing it. However, we can also flush kexec relocation buffers and if new kernel image is already in place (i.e. crash kernel), we can also flush the new kernel image itself. Signed-off-by: Pasha Tatashin Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210930143113.1502553-5-pasha.tatashin@soleen.com Signed-off-by: Will Deacon --- arch/arm64/kernel/machine_kexec.c | 58 ++++++++++++++----------------- 1 file changed, 26 insertions(+), 32 deletions(-) diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 213d56c14f60..b6d5a02cba2e 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -60,29 +60,6 @@ void machine_kexec_cleanup(struct kimage *kimage) /* Empty routine needed to avoid build errors. */ } -int machine_kexec_post_load(struct kimage *kimage) -{ - void *reloc_code = page_to_virt(kimage->control_code_page); - - memcpy(reloc_code, arm64_relocate_new_kernel, - arm64_relocate_new_kernel_size); - kimage->arch.kern_reloc = __pa(reloc_code); - kexec_image_info(kimage); - - /* - * For execution with the MMU off, reloc_code needs to be cleaned to the - * PoC and invalidated from the I-cache. - */ - dcache_clean_inval_poc((unsigned long)reloc_code, - (unsigned long)reloc_code + - arm64_relocate_new_kernel_size); - icache_inval_pou((uintptr_t)reloc_code, - (uintptr_t)reloc_code + - arm64_relocate_new_kernel_size); - - return 0; -} - /** * machine_kexec_prepare - Prepare for a kexec reboot. * @@ -163,6 +140,32 @@ static void kexec_segment_flush(const struct kimage *kimage) } } +int machine_kexec_post_load(struct kimage *kimage) +{ + void *reloc_code = page_to_virt(kimage->control_code_page); + + /* If in place flush new kernel image, else flush lists and buffers */ + if (kimage->head & IND_DONE) + kexec_segment_flush(kimage); + else + kexec_list_flush(kimage); + + memcpy(reloc_code, arm64_relocate_new_kernel, + arm64_relocate_new_kernel_size); + kimage->arch.kern_reloc = __pa(reloc_code); + kexec_image_info(kimage); + + /* Flush the reloc_code in preparation for its execution. */ + dcache_clean_inval_poc((unsigned long)reloc_code, + (unsigned long)reloc_code + + arm64_relocate_new_kernel_size); + icache_inval_pou((uintptr_t)reloc_code, + (uintptr_t)reloc_code + + arm64_relocate_new_kernel_size); + + return 0; +} + /** * machine_kexec - Do the kexec reboot. * @@ -180,13 +183,6 @@ void machine_kexec(struct kimage *kimage) WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()), "Some CPUs may be stale, kdump will be unreliable.\n"); - /* Flush the kimage list and its buffers. */ - kexec_list_flush(kimage); - - /* Flush the new image if already in place. */ - if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE)) - kexec_segment_flush(kimage); - pr_info("Bye!\n"); local_daif_mask(); @@ -261,8 +257,6 @@ void arch_kexec_protect_crashkres(void) { int i; - kexec_segment_flush(kexec_crash_image); - for (i = 0; i < kexec_crash_image->nr_segments; i++) set_memory_valid( __phys_to_virt(kexec_crash_image->segment[i].mem),