From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968943AbeE3JOI (ORCPT ); Wed, 30 May 2018 05:14:08 -0400 Received: from mail-pg0-f68.google.com ([74.125.83.68]:34809 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968847AbeE3JN0 (ORCPT ); Wed, 30 May 2018 05:13:26 -0400 X-Google-Smtp-Source: ADUXVKIYkg1XePl03K+GiXrjZhrvlzjch2CG9VClmAlbA8vZGg7Xcs87eceQ3a2eJCcIWIoZ3f3PBg== From: YaoJun To: kernel-hardening@lists.openwall.com Cc: catalin.marinas@arm.com, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com Subject: [PATCH 4/4] arm64/mm: migrate swapper_pg_dir Date: Wed, 30 May 2018 17:12:59 +0800 Message-Id: <20180530091259.9386-5-yaojun8558363@gmail.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180530091259.9386-1-yaojun8558363@gmail.com> References: <20180530091259.9386-1-yaojun8558363@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Migrate swapper_pg_dir and tramp_pg_dir. And its placement in the virtual address space does not correlate with the placement of the kernel. Signed-off-by: YaoJun --- arch/arm64/mm/mmu.c | 67 +++++++++++++++++++++++++++++++-------------- 1 file changed, 46 insertions(+), 21 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 26ba3e70a91c..b508de2cc6c4 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -57,6 +57,9 @@ EXPORT_SYMBOL(kimage_voffset); phys_addr_t __pa_swapper_pg_dir; pgd_t *new_swapper_pg_dir = swapper_pg_dir; +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +pgd_t *new_tramp_pg_dir; +#endif /* * Empty_zero_page is a special page that is used for zero-initialized data @@ -105,6 +108,25 @@ static phys_addr_t __init early_pgtable_alloc(void) return phys; } +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +static phys_addr_t __init early_pgtables_alloc(int num) +{ + int i; + phys_addr_t phys; + void *ptr; + + phys = memblock_alloc(PAGE_SIZE * num, PAGE_SIZE); + + for (i = 0; i < num; i++) { + ptr = pte_set_fixmap(phys + i * PAGE_SIZE); + memset(ptr, 0, PAGE_SIZE); + pte_clear_fixmap(); + } + + return phys; +} +#endif + static bool pgattr_change_is_safe(u64 old, u64 new) { /* @@ -554,6 +576,10 @@ static int __init map_entry_trampoline(void) __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, prot, pgd_pgtable_alloc, 0); + memcpy(new_tramp_pg_dir, tramp_pg_dir, PGD_SIZE); + memblock_free(__pa_symbol(tramp_pg_dir), + __pa_symbol(swapper_pg_dir) - __pa_symbol(tramp_pg_dir)); + /* Map both the text and data into the kernel page table */ __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { @@ -631,36 +657,35 @@ static void __init map_kernel(pgd_t *pgdp) */ void __init paging_init(void) { - phys_addr_t pgd_phys = early_pgtable_alloc(); - pgd_t *pgdp = pgd_set_fixmap(pgd_phys); + phys_addr_t pgd_phys; + pgd_t *pgdp; + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + int pages; + + pages = (__pa_symbol(swapper_pg_dir) - __pa_symbol(tramp_pg_dir) + + PAGE_SIZE) >> PAGE_SHIFT; + pgd_phys = early_pgtables_alloc(pages); + new_tramp_pg_dir = __va(pgd_phys); + __pa_swapper_pg_dir = pgd_phys + PAGE_SIZE; +#else + pgd_phys = early_pgtable_alloc(); + __pa_swapper_pg_dir = pgd_phys; +#endif + new_swapper_pg_dir = __va(__pa_swapper_pg_dir); - __pa_swapper_pg_dir = __pa_symbol(swapper_pg_dir); + pgdp = pgd_set_fixmap(__pa_swapper_pg_dir); map_kernel(pgdp); map_mem(pgdp); - /* - * We want to reuse the original swapper_pg_dir so we don't have to - * communicate the new address to non-coherent secondaries in - * secondary_entry, and so cpu_switch_mm can generate the address with - * adrp+add rather than a load from some global variable. - * - * To do this we need to go via a temporary pgd. - */ - cpu_replace_ttbr1(pgd_phys); - memcpy(swapper_pg_dir, pgdp, PGD_SIZE); cpu_replace_ttbr1(__pa_swapper_pg_dir); + init_mm.pgd = new_swapper_pg_dir; pgd_clear_fixmap(); - memblock_free(pgd_phys, PAGE_SIZE); - /* - * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd - * allocated with it. - */ - memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE, - __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir) - - PAGE_SIZE); + memblock_free(__pa_symbol(swapper_pg_dir), + __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir)); } /* -- 2.17.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: yaojun8558363@gmail.com (YaoJun) Date: Wed, 30 May 2018 17:12:59 +0800 Subject: [PATCH 4/4] arm64/mm: migrate swapper_pg_dir In-Reply-To: <20180530091259.9386-1-yaojun8558363@gmail.com> References: <20180530091259.9386-1-yaojun8558363@gmail.com> Message-ID: <20180530091259.9386-5-yaojun8558363@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Migrate swapper_pg_dir and tramp_pg_dir. And its placement in the virtual address space does not correlate with the placement of the kernel. Signed-off-by: YaoJun --- arch/arm64/mm/mmu.c | 67 +++++++++++++++++++++++++++++++-------------- 1 file changed, 46 insertions(+), 21 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 26ba3e70a91c..b508de2cc6c4 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -57,6 +57,9 @@ EXPORT_SYMBOL(kimage_voffset); phys_addr_t __pa_swapper_pg_dir; pgd_t *new_swapper_pg_dir = swapper_pg_dir; +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +pgd_t *new_tramp_pg_dir; +#endif /* * Empty_zero_page is a special page that is used for zero-initialized data @@ -105,6 +108,25 @@ static phys_addr_t __init early_pgtable_alloc(void) return phys; } +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +static phys_addr_t __init early_pgtables_alloc(int num) +{ + int i; + phys_addr_t phys; + void *ptr; + + phys = memblock_alloc(PAGE_SIZE * num, PAGE_SIZE); + + for (i = 0; i < num; i++) { + ptr = pte_set_fixmap(phys + i * PAGE_SIZE); + memset(ptr, 0, PAGE_SIZE); + pte_clear_fixmap(); + } + + return phys; +} +#endif + static bool pgattr_change_is_safe(u64 old, u64 new) { /* @@ -554,6 +576,10 @@ static int __init map_entry_trampoline(void) __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, prot, pgd_pgtable_alloc, 0); + memcpy(new_tramp_pg_dir, tramp_pg_dir, PGD_SIZE); + memblock_free(__pa_symbol(tramp_pg_dir), + __pa_symbol(swapper_pg_dir) - __pa_symbol(tramp_pg_dir)); + /* Map both the text and data into the kernel page table */ __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { @@ -631,36 +657,35 @@ static void __init map_kernel(pgd_t *pgdp) */ void __init paging_init(void) { - phys_addr_t pgd_phys = early_pgtable_alloc(); - pgd_t *pgdp = pgd_set_fixmap(pgd_phys); + phys_addr_t pgd_phys; + pgd_t *pgdp; + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + int pages; + + pages = (__pa_symbol(swapper_pg_dir) - __pa_symbol(tramp_pg_dir) + + PAGE_SIZE) >> PAGE_SHIFT; + pgd_phys = early_pgtables_alloc(pages); + new_tramp_pg_dir = __va(pgd_phys); + __pa_swapper_pg_dir = pgd_phys + PAGE_SIZE; +#else + pgd_phys = early_pgtable_alloc(); + __pa_swapper_pg_dir = pgd_phys; +#endif + new_swapper_pg_dir = __va(__pa_swapper_pg_dir); - __pa_swapper_pg_dir = __pa_symbol(swapper_pg_dir); + pgdp = pgd_set_fixmap(__pa_swapper_pg_dir); map_kernel(pgdp); map_mem(pgdp); - /* - * We want to reuse the original swapper_pg_dir so we don't have to - * communicate the new address to non-coherent secondaries in - * secondary_entry, and so cpu_switch_mm can generate the address with - * adrp+add rather than a load from some global variable. - * - * To do this we need to go via a temporary pgd. - */ - cpu_replace_ttbr1(pgd_phys); - memcpy(swapper_pg_dir, pgdp, PGD_SIZE); cpu_replace_ttbr1(__pa_swapper_pg_dir); + init_mm.pgd = new_swapper_pg_dir; pgd_clear_fixmap(); - memblock_free(pgd_phys, PAGE_SIZE); - /* - * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd - * allocated with it. - */ - memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE, - __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir) - - PAGE_SIZE); + memblock_free(__pa_symbol(swapper_pg_dir), + __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir)); } /* -- 2.17.0