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author | Helge Deller <deller@gmx.de> | 2013-11-20 23:07:42 +0100 |
---|---|---|
committer | Helge Deller <deller@gmx.de> | 2013-11-30 20:57:50 +0100 |
commit | 0576da2c08e3d332f1b0653030d28ab804585ab6 (patch) | |
tree | 6fba568d4bbb0a32989ea68dedca00cfcc75f99f /arch/parisc/kernel | |
parent | dc1ccc48159d63eca5089e507c82c7d22ef60839 (diff) | |
download | linux-0576da2c08e3d332f1b0653030d28ab804585ab6.tar.bz2 |
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 <deller@gmx.de>
Cc: <stable@vger.kernel.org> # 3.10+
Diffstat (limited to 'arch/parisc/kernel')
-rw-r--r-- | arch/parisc/kernel/sys_parisc.c | 25 |
1 files changed, 15 insertions, 10 deletions
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; } |