diff options
| -rw-r--r-- | arch/x86/include/asm/mmu_context.h | 15 | ||||
| -rw-r--r-- | arch/x86/include/asm/pkeys.h | 11 | ||||
| -rw-r--r-- | include/linux/pkeys.h | 12 | ||||
| -rw-r--r-- | mm/mprotect.c | 30 |
4 files changed, 45 insertions, 23 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index d8abfcf524d1..af0251fc85ed 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -4,6 +4,7 @@ #include <asm/desc.h> #include <linux/atomic.h> #include <linux/mm_types.h> +#include <linux/pkeys.h> #include <trace/events/tlb.h> @@ -195,16 +196,20 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, mpx_notify_unmap(mm, vma, start, end); } +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS static inline int vma_pkey(struct vm_area_struct *vma) { - u16 pkey = 0; -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3; - pkey = (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; -#endif - return pkey; + + return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; +} +#else +static inline int vma_pkey(struct vm_area_struct *vma) +{ + return 0; } +#endif static inline bool __pkru_allows_pkey(u16 pkey, bool write) { diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h index 7b84565c916c..33777c291a85 100644 --- a/arch/x86/include/asm/pkeys.h +++ b/arch/x86/include/asm/pkeys.h @@ -1,7 +1,12 @@ #ifndef _ASM_X86_PKEYS_H #define _ASM_X86_PKEYS_H -#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1) +#define PKEY_DEDICATED_EXECUTE_ONLY 15 +/* + * Consider the PKEY_DEDICATED_EXECUTE_ONLY key unavailable. + */ +#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? \ + PKEY_DEDICATED_EXECUTE_ONLY : 1) extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val); @@ -10,7 +15,6 @@ extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, * Try to dedicate one of the protection keys to be used as an * execute-only protection key. */ -#define PKEY_DEDICATED_EXECUTE_ONLY 15 extern int __execute_only_pkey(struct mm_struct *mm); static inline int execute_only_pkey(struct mm_struct *mm) { @@ -31,4 +35,7 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, return __arch_override_mprotect_pkey(vma, prot, pkey); } +extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val); + #endif /*_ASM_X86_PKEYS_H */ diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h index 1d405a2b7272..0030b4024559 100644 --- a/include/linux/pkeys.h +++ b/include/linux/pkeys.h @@ -18,16 +18,4 @@ #define PKEY_DEDICATED_EXECUTE_ONLY 0 #endif /* ! CONFIG_ARCH_HAS_PKEYS */ -/* - * This is called from mprotect_pkey(). - * - * Returns true if the protection keys is valid. - */ -static inline bool validate_pkey(int pkey) -{ - if (pkey < 0) - return false; - return (pkey < arch_max_pkey()); -} - #endif /* _LINUX_PKEYS_H */ diff --git a/mm/mprotect.c b/mm/mprotect.c index a4830f0325fe..dd3f40a2935f 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -352,8 +352,11 @@ fail: return error; } -SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, - unsigned long, prot) +/* + * pkey==-1 when doing a legacy mprotect() + */ +static int do_mprotect_pkey(unsigned long start, size_t len, + unsigned long prot, int pkey) { unsigned long nstart, end, tmp, reqprot; struct vm_area_struct *vma, *prev; @@ -361,6 +364,12 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); const bool rier = (current->personality & READ_IMPLIES_EXEC) && (prot & PROT_READ); + /* + * A temporary safety check since we are not validating + * the pkey before we introduce the allocation code. + */ + if (pkey != -1) + return -EINVAL; prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ @@ -409,7 +418,7 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, for (nstart = start ; ; ) { unsigned long newflags; - int pkey = arch_override_mprotect_pkey(vma, prot, -1); + int new_vma_pkey; /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ @@ -417,7 +426,8 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, if (rier && (vma->vm_flags & VM_MAYEXEC)) prot |= PROT_EXEC; - newflags = calc_vm_prot_bits(prot, pkey); + new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); + newflags = calc_vm_prot_bits(prot, new_vma_pkey); newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); /* newflags >> 4 shift VM_MAY% in place of VM_% */ @@ -454,3 +464,15 @@ out: up_write(¤t->mm->mmap_sem); return error; } + +SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, + unsigned long, prot) +{ + return do_mprotect_pkey(start, len, prot, -1); +} + +SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, + unsigned long, prot, int, pkey) +{ + return do_mprotect_pkey(start, len, prot, pkey); +} |