From 0576da2c08e3d332f1b0653030d28ab804585ab6 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Wed, 20 Nov 2013 23:07:42 +0100 Subject: parisc: fix mmap(MAP_FIXED|MAP_SHARED) to already mmapped address locale-gen on Debian showed a strange problem on parisc: mmap2(NULL, 536870912, PROT_NONE, MAP_SHARED, 3, 0) = 0x42a54000 mmap2(0x42a54000, 103860, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 3, 0) = -1 EINVAL (Invalid argument) Basically it was just trying to re-mmap() a file at the same address which it was given by a previous mmap() call. But this remapping failed with EINVAL. The problem is, that when MAP_FIXED and MAP_SHARED flags were used, we didn't included the mapping-based offset when we verified the alignment of the given fixed address against the offset which we calculated it in the previous call. Signed-off-by: Helge Deller Cc: # 3.10+ --- arch/parisc/kernel/sys_parisc.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index 5dfd248e3f1a..0d3a9d4927b5 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -61,8 +61,15 @@ static int get_offset(struct address_space *mapping) return (unsigned long) mapping >> 8; } -static unsigned long get_shared_area(struct address_space *mapping, - unsigned long addr, unsigned long len, unsigned long pgoff) +static unsigned long shared_align_offset(struct file *filp, unsigned long pgoff) +{ + struct address_space *mapping = filp ? filp->f_mapping : NULL; + + return (get_offset(mapping) + pgoff) << PAGE_SHIFT; +} + +static unsigned long get_shared_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff) { struct vm_unmapped_area_info info; @@ -71,7 +78,7 @@ static unsigned long get_shared_area(struct address_space *mapping, info.low_limit = PAGE_ALIGN(addr); info.high_limit = TASK_SIZE; info.align_mask = PAGE_MASK & (SHMLBA - 1); - info.align_offset = (get_offset(mapping) + pgoff) << PAGE_SHIFT; + info.align_offset = shared_align_offset(filp, pgoff); return vm_unmapped_area(&info); } @@ -82,20 +89,18 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, return -ENOMEM; if (flags & MAP_FIXED) { if ((flags & MAP_SHARED) && - (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) + (addr - shared_align_offset(filp, pgoff)) & (SHMLBA - 1)) return -EINVAL; return addr; } if (!addr) addr = TASK_UNMAPPED_BASE; - if (filp) { - addr = get_shared_area(filp->f_mapping, addr, len, pgoff); - } else if(flags & MAP_SHARED) { - addr = get_shared_area(NULL, addr, len, pgoff); - } else { + if (filp || (flags & MAP_SHARED)) + addr = get_shared_area(filp, addr, len, pgoff); + else addr = get_unshared_area(addr, len); - } + return addr; } -- cgit v1.2.3