diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-25 19:48:08 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-25 19:48:08 (GMT) |
commit | bf16ae250999e76aff0491a362073a552db965fc (patch) | |
tree | 9b012f0f4e9cc146648fe8914346452563f999d9 /arch/x86 | |
parent | 0b79dada976198cb1a4c043068e3b44d5cab2a5a (diff) | |
parent | 1526a756fba5b1f2eb5001b8e8de2a0ea1bd2c66 (diff) | |
download | linux-fsl-qoriq-bf16ae250999e76aff0491a362073a552db965fc.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-pat
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-pat:
generic: add ioremap_wc() interface wrapper
/dev/mem: make promisc the default
pat: cleanups
x86: PAT use reserve free memtype in mmap of /dev/mem
x86: PAT phys_mem_access_prot_allowed for dev/mem mmap
x86: PAT avoid aliasing in /dev/mem read/write
devmem: add range_is_allowed() check to mmap of /dev/mem
x86: introduce /dev/mem restrictions with a config option
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/Kconfig.debug | 11 | ||||
-rw-r--r-- | arch/x86/mm/init_32.c | 19 | ||||
-rw-r--r-- | arch/x86/mm/init_64.c | 20 | ||||
-rw-r--r-- | arch/x86/mm/ioremap.c | 29 | ||||
-rw-r--r-- | arch/x86/mm/pat.c | 175 |
5 files changed, 240 insertions, 14 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 610aaec..239fd9f 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -5,6 +5,17 @@ config TRACE_IRQFLAGS_SUPPORT source "lib/Kconfig.debug" +config NONPROMISC_DEVMEM + bool "Disable promiscuous /dev/mem" + help + The /dev/mem file by default only allows userspace access to PCI + space and the BIOS code and data regions. This is sufficient for + dosemu and X and all common users of /dev/mem. With this config + option, you allow userspace access to all of memory, including + kernel and userspace memory. Accidental access to this is + obviously disasterous, but specific access can be used by people + debugging the kernel. + config EARLY_PRINTK bool "Early printk" if EMBEDDED default y diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 08aa187..baf7c4f 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -227,6 +227,25 @@ static inline int page_kills_ppro(unsigned long pagenr) return 0; } +/* + * devmem_is_allowed() checks to see if /dev/mem access to a certain address + * is valid. The argument is a physical page number. + * + * + * On x86, access has to be given to the first megabyte of ram because that area + * contains bios code and data regions used by X and dosemu and similar apps. + * Access has to be given to non-kernel-ram areas as well, these contain the PCI + * mmio resources as well as potential bios/acpi data regions. + */ +int devmem_is_allowed(unsigned long pagenr) +{ + if (pagenr <= 256) + return 1; + if (!page_is_ram(pagenr)) + return 1; + return 0; +} + #ifdef CONFIG_HIGHMEM pte_t *kmap_pte; pgprot_t kmap_prot; diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index b798e7b..0cca626 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -663,6 +663,26 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); #endif /* CONFIG_MEMORY_HOTPLUG */ +/* + * devmem_is_allowed() checks to see if /dev/mem access to a certain address + * is valid. The argument is a physical page number. + * + * + * On x86, access has to be given to the first megabyte of ram because that area + * contains bios code and data regions used by X and dosemu and similar apps. + * Access has to be given to non-kernel-ram areas as well, these contain the PCI + * mmio resources as well as potential bios/acpi data regions. + */ +int devmem_is_allowed(unsigned long pagenr) +{ + if (pagenr <= 256) + return 1; + if (!page_is_ram(pagenr)) + return 1; + return 0; +} + + static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules, kcore_vsyscall; diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 36a3f7d..d176b23 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -336,6 +336,35 @@ void iounmap(volatile void __iomem *addr) } EXPORT_SYMBOL(iounmap); +/* + * Convert a physical pointer to a virtual kernel pointer for /dev/mem + * access + */ +void *xlate_dev_mem_ptr(unsigned long phys) +{ + void *addr; + unsigned long start = phys & PAGE_MASK; + + /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */ + if (page_is_ram(start >> PAGE_SHIFT)) + return __va(phys); + + addr = (void *)ioremap(start, PAGE_SIZE); + if (addr) + addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK)); + + return addr; +} + +void unxlate_dev_mem_ptr(unsigned long phys, void *addr) +{ + if (page_is_ram(phys >> PAGE_SHIFT)) + return; + + iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK)); + return; +} + #ifdef CONFIG_X86_32 int __initdata early_ioremap_debug; diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 72c0f60..ef8b64b 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -11,6 +11,7 @@ #include <linux/kernel.h> #include <linux/gfp.h> #include <linux/fs.h> +#include <linux/bootmem.h> #include <asm/msr.h> #include <asm/tlbflush.h> @@ -21,6 +22,7 @@ #include <asm/cacheflush.h> #include <asm/fcntl.h> #include <asm/mtrr.h> +#include <asm/io.h> int pat_wc_enabled = 1; @@ -190,6 +192,21 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot, return 0; } +/* + * req_type typically has one of the: + * - _PAGE_CACHE_WB + * - _PAGE_CACHE_WC + * - _PAGE_CACHE_UC_MINUS + * - _PAGE_CACHE_UC + * + * req_type will have a special case value '-1', when requester want to inherit + * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS. + * + * If ret_type is NULL, function will return an error if it cannot reserve the + * region with req_type. If ret_type is non-null, function will return + * available type in ret_type in case of no error. In case of any error + * it will return a negative return value. + */ int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long *ret_type) { @@ -200,9 +217,14 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, /* Only track when pat_wc_enabled */ if (!pat_wc_enabled) { - if (ret_type) - *ret_type = req_type; - + /* This is identical to page table setting without PAT */ + if (ret_type) { + if (req_type == -1) { + *ret_type = _PAGE_CACHE_WB; + } else { + *ret_type = req_type; + } + } return 0; } @@ -214,8 +236,29 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, return 0; } - req_type &= _PAGE_CACHE_MASK; - err = pat_x_mtrr_type(start, end, req_type, &actual_type); + if (req_type == -1) { + /* + * Special case where caller wants to inherit from mtrr or + * existing pat mapping, defaulting to UC_MINUS in case of + * no match. + */ + u8 mtrr_type = mtrr_type_lookup(start, end); + if (mtrr_type == 0xFE) { /* MTRR match error */ + err = -1; + } + + if (mtrr_type == MTRR_TYPE_WRBACK) { + req_type = _PAGE_CACHE_WB; + actual_type = _PAGE_CACHE_WB; + } else { + req_type = _PAGE_CACHE_UC_MINUS; + actual_type = _PAGE_CACHE_UC_MINUS; + } + } else { + req_type &= _PAGE_CACHE_MASK; + err = pat_x_mtrr_type(start, end, req_type, &actual_type); + } + if (err) { if (ret_type) *ret_type = actual_type; @@ -241,7 +284,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, struct memtype *saved_ptr; if (parse->start >= end) { - printk("New Entry\n"); + pr_debug("New Entry\n"); list_add(&new_entry->nd, parse->nd.prev); new_entry = NULL; break; @@ -343,7 +386,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - printk("Overlap at 0x%Lx-0x%Lx\n", + printk(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ list_add(&new_entry->nd, &saved_ptr->nd); @@ -353,7 +396,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (err) { - printk( + printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n", start, end, cattr_name(new_entry->type), cattr_name(req_type)); @@ -365,16 +408,16 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (new_entry) { /* No conflict. Not yet added to the list. Add to the tail */ list_add_tail(&new_entry->nd, &memtype_list); - printk("New Entry\n"); - } + pr_debug("New Entry\n"); + } if (ret_type) { - printk( + pr_debug( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", start, end, cattr_name(actual_type), cattr_name(req_type), cattr_name(*ret_type)); } else { - printk( + pr_debug( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n", start, end, cattr_name(actual_type), cattr_name(req_type)); @@ -411,11 +454,115 @@ int free_memtype(u64 start, u64 end) spin_unlock(&memtype_lock); if (err) { - printk(KERN_DEBUG "%s:%d freeing invalid memtype %Lx-%Lx\n", + printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n", current->comm, current->pid, start, end); } - printk( "free_memtype request 0x%Lx-0x%Lx\n", start, end); + pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end); return err; } + +/* + * /dev/mem mmap interface. The memtype used for mapping varies: + * - Use UC for mappings with O_SYNC flag + * - Without O_SYNC flag, if there is any conflict in reserve_memtype, + * inherit the memtype from existing mapping. + * - Else use UC_MINUS memtype (for backward compatibility with existing + * X drivers. + */ +pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot) +{ + return vma_prot; +} + +int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t *vma_prot) +{ + u64 offset = ((u64) pfn) << PAGE_SHIFT; + unsigned long flags = _PAGE_CACHE_UC_MINUS; + unsigned long ret_flags; + int retval; + + if (file->f_flags & O_SYNC) { + flags = _PAGE_CACHE_UC; + } + +#ifdef CONFIG_X86_32 + /* + * On the PPro and successors, the MTRRs are used to set + * memory types for physical addresses outside main memory, + * so blindly setting UC or PWT on those pages is wrong. + * For Pentiums and earlier, the surround logic should disable + * caching for the high addresses through the KEN pin, but + * we maintain the tradition of paranoia in this code. + */ + if (!pat_wc_enabled && + ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) || + test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) || + test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) || + test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) && + (pfn << PAGE_SHIFT) >= __pa(high_memory)) { + flags = _PAGE_CACHE_UC; + } +#endif + + /* + * With O_SYNC, we can only take UC mapping. Fail if we cannot. + * Without O_SYNC, we want to get + * - WB for WB-able memory and no other conflicting mappings + * - UC_MINUS for non-WB-able memory with no other conflicting mappings + * - Inherit from confliting mappings otherwise + */ + if (flags != _PAGE_CACHE_UC_MINUS) { + retval = reserve_memtype(offset, offset + size, flags, NULL); + } else { + retval = reserve_memtype(offset, offset + size, -1, &ret_flags); + } + + if (retval < 0) + return 0; + + flags = ret_flags; + + if (pfn <= max_pfn_mapped && + ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) { + free_memtype(offset, offset + size); + printk(KERN_INFO + "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n", + current->comm, current->pid, + cattr_name(flags), + offset, offset + size); + return 0; + } + + *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) | + flags); + return 1; +} + +void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) +{ + u64 addr = (u64)pfn << PAGE_SHIFT; + unsigned long flags; + unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK); + + reserve_memtype(addr, addr + size, want_flags, &flags); + if (flags != want_flags) { + printk(KERN_INFO + "%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n", + current->comm, current->pid, + cattr_name(want_flags), + addr, addr + size, + cattr_name(flags)); + } +} + +void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) +{ + u64 addr = (u64)pfn << PAGE_SHIFT; + + free_memtype(addr, addr + size); +} + |