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| author | Michael Schmitz <schmitzmic@gmail.com> | 2018-05-14 23:10:53 +1200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-03 11:23:05 +0200 |
| commit | 5692dcf90e6907e6ea09707b6c7426f36f905772 (patch) | |
| tree | 5a1899b5b54804b281ef1a1d3cd5533f6d4cb299 /arch/m68k | |
| parent | 7a68dcdc9d22080c974bb5472cae7d1799ec8607 (diff) | |
m68k/mm: Adjust VM area to be unmapped by gap size for __iounmap()
commit 3f90f9ef2dda316d64e420d5d51ba369587ccc55 upstream.
If 020/030 support is enabled, get_io_area() leaves an IO_SIZE gap
between mappings which is added to the vm_struct representing the
mapping. __ioremap() uses the actual requested size (after alignment),
while __iounmap() is passed the size from the vm_struct.
On 020/030, early termination descriptors are used to set up mappings of
extent 'size', which are validated on unmapping. The unmapped gap of
size IO_SIZE defeats the sanity check of the pmd tables, causing
__iounmap() to loop forever on 030.
On 040/060, unmapping of page table entries does not check for a valid
mapping, so the umapping loop always completes there.
Adjust size to be unmapped by the gap that had been added in the
vm_struct prior.
This fixes the hang in atari_platform_init() reported a long time ago,
and a similar one reported by Finn recently (addressed by removing
ioremap() use from the SWIM driver.
Tested on my Falcon in 030 mode - untested but should work the same on
040/060 (the extra page tables cleared there would never have been set
up anyway).
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
[geert: Minor commit description improvements]
[geert: This was fixed in 2.4.23, but not in 2.5.x]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/mm/kmap.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/m68k/mm/kmap.c b/arch/m68k/mm/kmap.c index 6e4955bc542b..fcd52cefee29 100644 --- a/arch/m68k/mm/kmap.c +++ b/arch/m68k/mm/kmap.c @@ -88,7 +88,8 @@ static inline void free_io_area(void *addr) for (p = &iolist ; (tmp = *p) ; p = &tmp->next) { if (tmp->addr == addr) { *p = tmp->next; - __iounmap(tmp->addr, tmp->size); + /* remove gap added in get_io_area() */ + __iounmap(tmp->addr, tmp->size - IO_SIZE); kfree(tmp); return; } |