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tile: map data region shadow of kernel as R/W 

This is necessary for things like reading /proc/kcore, doing ftrace,
etc.  It happens by default when using huge pages to map the kernel
data, but not when using small pages.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
This commit is contained in:
Chris Metcalf 2015-03-27 14:35:31 -04:00
parent 49e4e15619
commit a84f24230c
1 changed files with 5 additions and 2 deletions
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7
arch/tile/mm/init.c
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@ -233,9 +233,12 @@ static pgprot_t __init init_pgprot(ulong address)
if (kdata_huge)
return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
/* We map the aliased pages of permanent text inaccessible. */
/*
* We map the aliased pages of permanent text so we can
* update them if necessary, for ftrace, etc.
*/
if (address < (ulong) _sinittext - CODE_DELTA)
return PAGE_NONE;
return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
/* We map read-only data non-coherent for performance. */
if ((address >= (ulong) __start_rodata &&