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authorMichael Schmitz <schmitzmic@gmail.com>2018-05-14 23:10:53 +1200
committerGeert Uytterhoeven <geert@linux-m68k.org>2018-05-24 12:00:27 +0200
commit3f90f9ef2dda316d64e420d5d51ba369587ccc55 (patch)
treefa680ee541b2c7ed982b19ea1365d2c71ba5c37f /arch/m68k/mm
parent5bcf938117479f6e07dd5f97e3d8e56b5657e22a (diff)
m68k/mm: Adjust VM area to be unmapped by gap size for __iounmap()
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
Diffstat (limited to 'arch/m68k/mm')
-rw-r--r--arch/m68k/mm/kmap.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/m68k/mm/kmap.c b/arch/m68k/mm/kmap.c
index c2a38321c96d..3b420f6d8822 100644
--- a/arch/m68k/mm/kmap.c
+++ b/arch/m68k/mm/kmap.c
@@ -89,7 +89,8 @@ 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;
}