From b615bbbff1c4d6fcd13007e75d75f6510aeb3808 Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Wed, 13 Aug 2014 09:04:49 -0700 Subject: arm: use generic fixmap.h ARM is different from other architectures in that fixmap pages are indexed with a positive offset from FIXADDR_START. Other architectures index with a negative offset from FIXADDR_TOP. In order to use the generic fixmap.h definitions, this patch redefines FIXADDR_TOP to be inclusive of the useable range. That is, FIXADDR_TOP is the virtual address of the topmost fixed page. The newly defined FIXADDR_END is the first virtual address past the fixed mappings. Signed-off-by: Mark Salter Reviewed-by: Doug Anderson [kees: update for a05e54c103b0 ("ARM: 8031/2: change fixmap ...")] Signed-off-by: Kees Cook Cc: Laura Abbott Cc: Rob Herring Acked-by: Nicolas Pitre --- arch/arm/include/asm/fixmap.h | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 74124b0d0d79..a7add6f9315d 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -2,27 +2,18 @@ #define _ASM_FIXMAP_H #define FIXADDR_START 0xffc00000UL -#define FIXADDR_TOP 0xffe00000UL -#define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) +#define FIXADDR_END 0xffe00000UL +#define FIXADDR_TOP (FIXADDR_END - PAGE_SIZE) -#define FIX_KMAP_NR_PTES (FIXADDR_SIZE >> PAGE_SHIFT) +#include -#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) -#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) +enum fixed_addresses { + FIX_KMAP_BEGIN, + FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1, -extern void __this_fixmap_does_not_exist(void); + __end_of_fixed_addresses +}; -static inline unsigned long fix_to_virt(const unsigned int idx) -{ - if (idx >= FIX_KMAP_NR_PTES) - __this_fixmap_does_not_exist(); - return __fix_to_virt(idx); -} - -static inline unsigned int virt_to_fix(const unsigned long vaddr) -{ - BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); - return __virt_to_fix(vaddr); -} +#include #endif -- cgit v1.2.3 From 836a24183273e9db1c092246bd8e306b297d9917 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Wed, 2 Jul 2014 02:01:15 -0500 Subject: ARM: expand fixmap region to 3MB With commit a05e54c103b0 ("ARM: 8031/2: change fixmap mapping region to support 32 CPUs"), the fixmap region was expanded to 2MB, but it precluded any other uses of the fixmap region. In order to support other uses the fixmap region needs to be expanded beyond 2MB. Fortunately, the adjacent 1MB range 0xffe00000-0xfff00000 is availabe. Remove fixmap_page_table ptr and lookup the page table via the virtual address so that the fixmap region can span more that one pmd. The 2nd pmd is already created since it is shared with the vector page. Signed-off-by: Rob Herring [kees: fixed CONFIG_DEBUG_HIGHMEM get_fixmap() calls] [kees: moved pte allocation outside of CONFIG_HIGHMEM] Signed-off-by: Kees Cook Acked-by: Nicolas Pitre --- arch/arm/include/asm/fixmap.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index a7add6f9315d..d984ca69ce19 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -2,7 +2,7 @@ #define _ASM_FIXMAP_H #define FIXADDR_START 0xffc00000UL -#define FIXADDR_END 0xffe00000UL +#define FIXADDR_END 0xfff00000UL #define FIXADDR_TOP (FIXADDR_END - PAGE_SIZE) #include -- cgit v1.2.3 From 99b4ac9afce4129323b5b4c7002a942a9489914c Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 4 Apr 2014 23:27:49 +0200 Subject: arm: fixmap: implement __set_fixmap() This is used from set_fixmap() and clear_fixmap() via asm-generic/fixmap.h. Also makes sure that the fixmap allocation fits into the expected range. Based on patch by Rabin Vincent. Signed-off-by: Kees Cook Cc: Rabin Vincent Acked-by: Nicolas Pitre --- arch/arm/include/asm/fixmap.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index d984ca69ce19..714606f70425 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -14,6 +14,8 @@ enum fixed_addresses { __end_of_fixed_addresses }; +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); + #include #endif -- cgit v1.2.3 From ab0615e2d6fb074764a3e4d05f1326fa2fdb4627 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Thu, 24 Apr 2014 23:28:57 +0200 Subject: arm: use fixmap for text patching when text is RO Use fixmaps for text patching when the kernel text is read-only, inspired by x86. This makes jump labels and kprobes work with the currently available CONFIG_DEBUG_SET_MODULE_RONX and the upcoming CONFIG_DEBUG_RODATA options. Signed-off-by: Rabin Vincent [kees: fixed up for merge with "arm: use generic fixmap.h"] [kees: added parse acquire/release annotations to pass C=1 builds] [kees: always use stop_machine to keep TLB flushing local] Signed-off-by: Kees Cook Acked-by: Nicolas Pitre --- arch/arm/include/asm/fixmap.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 714606f70425..0415eae1df27 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -11,6 +11,10 @@ enum fixed_addresses { FIX_KMAP_BEGIN, FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1, + /* Support writing RO kernel text via kprobes, jump labels, etc. */ + FIX_TEXT_POKE0, + FIX_TEXT_POKE1, + __end_of_fixed_addresses }; -- cgit v1.2.3 From 80d6b0c2eed2a504f6740cd1f5ea76dc50abfc4d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 3 Apr 2014 13:29:50 -0700 Subject: ARM: mm: allow text and rodata sections to be read-only This introduces CONFIG_DEBUG_RODATA, making kernel text and rodata read-only. Additionally, this splits rodata from text so that rodata can also be NX, which may lead to wasted memory when aligning to SECTION_SIZE. The read-only areas are made writable during ftrace updates and kexec. Signed-off-by: Kees Cook Tested-by: Laura Abbott Acked-by: Nicolas Pitre --- arch/arm/include/asm/cacheflush.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h index 10e78d00a0bb..2d46862e7bef 100644 --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -487,6 +487,16 @@ int set_memory_rw(unsigned long addr, int numpages); int set_memory_x(unsigned long addr, int numpages); int set_memory_nx(unsigned long addr, int numpages); +#ifdef CONFIG_DEBUG_RODATA +void mark_rodata_ro(void); +void set_kernel_text_rw(void); +void set_kernel_text_ro(void); +#else +static inline void set_kernel_text_rw(void) { } +static inline void set_kernel_text_ro(void) { } +#endif + void flush_uprobe_xol_access(struct page *page, unsigned long uaddr, void *kaddr, unsigned long len); + #endif -- cgit v1.2.3