From fa5b6ec9e5274aeae2326e25995506a953e5f878 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:40 -0800 Subject: [PATCH 1/7] lib/Kconfig.debug: Add ARCH_HAS_DEBUG_VIRTUAL DEBUG_VIRTUAL currently depends on DEBUG_KERNEL && X86. arm64 is getting the same support. Rather than add a list of architectures, switch this to ARCH_HAS_DEBUG_VIRTUAL and let architectures select it as appropriate. Acked-by: Ingo Molnar Reviewed-by: Mark Rutland Tested-by: Mark Rutland Suggested-by: Mark Rutland Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- arch/x86/Kconfig | 1 + lib/Kconfig.debug | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e487493bbd47..f1d4e8f2131f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -46,6 +46,7 @@ config X86 select ARCH_CLOCKSOURCE_DATA select ARCH_DISCARD_MEMBLOCK select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI + select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FAST_MULTIPLIER diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index b06848a104e6..2aed31608b86 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -622,9 +622,12 @@ config DEBUG_VM_PGFLAGS If unsure, say N. +config ARCH_HAS_DEBUG_VIRTUAL + bool + config DEBUG_VIRTUAL bool "Debug VM translations" - depends on DEBUG_KERNEL && X86 + depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL help Enable some costly sanity checks in virtual to page code. This can catch mistakes with virt_to_page() and friends. From 2dece445b6dbdaa3d94f38ef44aa1b63bc2a6bb9 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:41 -0800 Subject: [PATCH 2/7] mm/cma: Cleanup highmem check 6b101e2a3ce4 ("mm/CMA: fix boot regression due to physical address of high_memory") added checks to use __pa_nodebug on x86 since CONFIG_DEBUG_VIRTUAL complains about high_memory not being linearlly mapped. arm64 is now getting support for CONFIG_DEBUG_VIRTUAL as well. Rather than add an explosion of arches to the #ifdef, switch to an alternate method to calculate the physical start of highmem using the page before highmem starts. This avoids the need for the #ifdef and extra __pa_nodebug calls. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- mm/cma.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index c960459eda7e..94b3460cd608 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -235,18 +235,13 @@ int __init cma_declare_contiguous(phys_addr_t base, phys_addr_t highmem_start; int ret = 0; -#ifdef CONFIG_X86 /* - * high_memory isn't direct mapped memory so retrieving its physical - * address isn't appropriate. But it would be useful to check the - * physical address of the highmem boundary so it's justifiable to get - * the physical address from it. On x86 there is a validation check for - * this case, so the following workaround is needed to avoid it. + * We can't use __pa(high_memory) directly, since high_memory + * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly) + * complain. Find the boundary by adding one to the last valid + * address. */ - highmem_start = __pa_nodebug(high_memory); -#else - highmem_start = __pa(high_memory); -#endif + highmem_start = __pa(high_memory - 1) + 1; pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n", __func__, &size, &base, &limit, &alignment); From 568c5fe5a54f2654f5a4c599c45b8a62ed9a2013 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:42 -0800 Subject: [PATCH 3/7] mm: Introduce lm_alias Certain architectures may have the kernel image mapped separately to alias the linear map. Introduce a macro lm_alias to translate a kernel image symbol into its linear alias. This is used in part with work to add CONFIG_DEBUG_VIRTUAL support for arm64. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- include/linux/mm.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index fe6b4036664a..5dc9c4650522 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -76,6 +76,10 @@ extern int mmap_rnd_compat_bits __read_mostly; #define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x))) #endif +#ifndef lm_alias +#define lm_alias(x) __va(__pa_symbol(x)) +#endif + /* * To prevent common memory management code establishing * a zero page mapping on a read fault. From b6e92aa81038ce57d298a87b4c44285a1d456c3e Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:43 -0800 Subject: [PATCH 4/7] kexec: Switch to __pa_symbol __pa_symbol is the correct api to get the physical address of kernel symbols. Switch to it to allow for better debug checking. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Acked-by: "Eric W. Biederman" Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- kernel/kexec_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 5617cc412444..a01974e1bf6b 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1399,7 +1399,7 @@ void __weak arch_crash_save_vmcoreinfo(void) phys_addr_t __weak paddr_vmcoreinfo_note(void) { - return __pa((unsigned long)(char *)&vmcoreinfo_note); + return __pa_symbol((unsigned long)(char *)&vmcoreinfo_note); } static int __init crash_save_vmcoreinfo_init(void) From 5c6a84a3f4558a6115fef1b59343c7ae56b3abc3 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:44 -0800 Subject: [PATCH 5/7] mm/kasan: Switch to using __pa_symbol and lm_alias __pa_symbol is the correct API to find the physical address of symbols. Switch to it to allow for debugging APIs to work correctly. Other functions such as p*d_populate may call __pa internally. Ensure that the address passed is in the linear region by calling lm_alias. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- mm/kasan/kasan_init.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c index 3f9a41cf0ac6..31238dad85fb 100644 --- a/mm/kasan/kasan_init.c +++ b/mm/kasan/kasan_init.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -49,7 +50,7 @@ static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr, pte_t *pte = pte_offset_kernel(pmd, addr); pte_t zero_pte; - zero_pte = pfn_pte(PFN_DOWN(__pa(kasan_zero_page)), PAGE_KERNEL); + zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_zero_page)), PAGE_KERNEL); zero_pte = pte_wrprotect(zero_pte); while (addr + PAGE_SIZE <= end) { @@ -69,7 +70,7 @@ static void __init zero_pmd_populate(pud_t *pud, unsigned long addr, next = pmd_addr_end(addr, end); if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) { - pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); continue; } @@ -92,9 +93,9 @@ static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr, if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) { pmd_t *pmd; - pud_populate(&init_mm, pud, kasan_zero_pmd); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); pmd = pmd_offset(pud, addr); - pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); continue; } @@ -135,11 +136,11 @@ void __init kasan_populate_zero_shadow(const void *shadow_start, * puds,pmds, so pgd_populate(), pud_populate() * is noops. */ - pgd_populate(&init_mm, pgd, kasan_zero_pud); + pgd_populate(&init_mm, pgd, lm_alias(kasan_zero_pud)); pud = pud_offset(pgd, addr); - pud_populate(&init_mm, pud, kasan_zero_pmd); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); pmd = pmd_offset(pud, addr); - pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); + pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_pte)); continue; } From 46f6236aa1c48e06b10a2fe0386ac4114b438622 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:45 -0800 Subject: [PATCH 6/7] mm/usercopy: Switch to using lm_alias The usercopy checking code currently calls __va(__pa(...)) to check for aliases on symbols. Switch to using lm_alias instead. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Acked-by: Kees Cook Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- mm/usercopy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/usercopy.c b/mm/usercopy.c index 3c8da0af9695..8345299e3e3b 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -108,13 +108,13 @@ static inline const char *check_kernel_text_object(const void *ptr, * __pa() is not just the reverse of __va(). This can be detected * and checked: */ - textlow_linear = (unsigned long)__va(__pa(textlow)); + textlow_linear = (unsigned long)lm_alias(textlow); /* No different mapping: we're done. */ if (textlow_linear == textlow) return NULL; /* Check the secondary mapping... */ - texthigh_linear = (unsigned long)__va(__pa(texthigh)); + texthigh_linear = (unsigned long)lm_alias(texthigh); if (overlaps(ptr, n, textlow_linear, texthigh_linear)) return ""; From 1a08e3d9e0ac4577ba89dbdb38f593fe050f88fc Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:46 -0800 Subject: [PATCH 7/7] drivers: firmware: psci: Use __pa_symbol for kernel symbol __pa_symbol is technically the macro that should be used for kernel symbols. Switch to this as a pre-requisite for DEBUG_VIRTUAL which will do bounds checking. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- drivers/firmware/psci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c index 6c60a5087caf..66a8793f3b37 100644 --- a/drivers/firmware/psci.c +++ b/drivers/firmware/psci.c @@ -383,7 +383,7 @@ static int psci_suspend_finisher(unsigned long index) u32 *state = __this_cpu_read(psci_power_state); return psci_ops.cpu_suspend(state[index - 1], - virt_to_phys(cpu_resume)); + __pa_symbol(cpu_resume)); } int psci_cpu_suspend_enter(unsigned long index)