From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e3.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m5AM1Hfd018873 for ; Tue, 10 Jun 2008 18:01:17 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m5AM17iv237874 for ; Tue, 10 Jun 2008 18:01:07 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m5AM17QP015317 for ; Tue, 10 Jun 2008 18:01:07 -0400 Date: Tue, 10 Jun 2008 18:01:07 -0400 From: Dave Kleikamp Message-Id: <20080610220106.10257.69841.sendpatchset@norville.austin.ibm.com> In-Reply-To: <20080610220055.10257.84465.sendpatchset@norville.austin.ibm.com> References: <20080610220055.10257.84465.sendpatchset@norville.austin.ibm.com> Subject: [RFC:PATCH 02/06] mm: Allow architectures to define additional protection bits Sender: owner-linux-mm@kvack.org Return-Path: To: linuxppc-dev list Cc: linux-mm , Andrew Morton , Linus Torvalds List-ID: This patch allows architectures to define functions to deal with additional protections bits for mmap() and mprotect(). arch_calc_vm_prot_bits() maps additonal protection bits to vm_flags arch_vm_get_page_prot() maps additional vm_flags to the vma's vm_page_prot arch_validate_prot() checks for valid values of the protection bits Note: vm_get_page_prot() is now pretty ugly. Suggestions? Signed-off-by: Dave Kleikamp --- include/linux/mman.h | 23 ++++++++++++++++++++++- mm/mmap.c | 5 +++-- mm/mprotect.c | 2 +- 3 files changed, 26 insertions(+), 4 deletions(-) diff -Nurp linux001/include/linux/mman.h linux002/include/linux/mman.h --- linux001/include/linux/mman.h 2008-06-05 10:08:01.000000000 -0500 +++ linux002/include/linux/mman.h 2008-06-10 16:48:59.000000000 -0500 @@ -34,6 +34,26 @@ static inline void vm_unacct_memory(long } /* + * Allow architectures to handle additional protection bits + */ + +#ifndef HAVE_ARCH_PROT_BITS +#define arch_calc_vm_prot_bits(prot) 0 +#define arch_vm_get_page_prot(vm_flags) __pgprot(0) + +/* + * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have + * already been masked out. + * + * Returns true if the prot flags are valid + */ +static inline int arch_validate_prot(unsigned long prot) +{ + return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0; +} +#endif /* HAVE_ARCH_PROT_BITS */ + +/* * Optimisation macro. It is equivalent to: * (x & bit1) ? bit2 : 0 * but this version is faster. @@ -51,7 +71,8 @@ calc_vm_prot_bits(unsigned long prot) { return _calc_vm_trans(prot, PROT_READ, VM_READ ) | _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | - _calc_vm_trans(prot, PROT_EXEC, VM_EXEC ); + _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) | + arch_calc_vm_prot_bits(prot); } /* diff -Nurp linux001/mm/mmap.c linux002/mm/mmap.c --- linux001/mm/mmap.c 2008-06-05 10:08:03.000000000 -0500 +++ linux002/mm/mmap.c 2008-06-10 16:48:59.000000000 -0500 @@ -72,8 +72,9 @@ pgprot_t protection_map[16] = { pgprot_t vm_get_page_prot(unsigned long vm_flags) { - return protection_map[vm_flags & - (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]; + return __pgprot(pgprot_val(protection_map[vm_flags & + (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) | + pgprot_val(arch_vm_get_page_prot(vm_flags))); } EXPORT_SYMBOL(vm_get_page_prot); diff -Nurp linux001/mm/mprotect.c linux002/mm/mprotect.c --- linux001/mm/mprotect.c 2008-06-05 10:08:03.000000000 -0500 +++ linux002/mm/mprotect.c 2008-06-10 16:48:59.000000000 -0500 @@ -239,7 +239,7 @@ sys_mprotect(unsigned long start, size_t end = start + len; if (end <= start) return -ENOMEM; - if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) + if (!arch_validate_prot(prot)) return -EINVAL; reqprot = prot; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org