moonjuice/kernel_arpi
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

powerpc: Add set_memory_{p/np}() and remove set_memory_attr()

Browse Source 
commit f222ab83df92acf72691a2021e1f0d99880dcdf1 upstream.

set_memory_attr() was implemented by commit 4d1755b6a7 ("powerpc/mm:
implement set_memory_attr()") because the set_memory_xx() couldn't
be used at that time to modify memory "on the fly" as explained it
the commit.

But set_memory_attr() uses set_pte_at() which leads to warnings when
CONFIG_DEBUG_VM is selected, because set_pte_at() is unexpected for
updating existing page table entries.

The check could be bypassed by using __set_pte_at() instead,
as it was the case before commit c988cfd38e ("powerpc/32:
use set_memory_attr()") but since commit 9f7853d760 ("powerpc/mm:
Fix set_memory_*() against concurrent accesses") it is now possible
to use set_memory_xx() functions to update page table entries
"on the fly" because the update is now atomic.

For DEBUG_PAGEALLOC we need to clear and set back _PAGE_PRESENT.
Add set_memory_np() and set_memory_p() for that.

Replace all uses of set_memory_attr() by the relevant set_memory_xx()
and remove set_memory_attr().

Fixes: c988cfd38e ("powerpc/32: use set_memory_attr()")
Cc: stable@vger.kernel.org
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Maxime Bizon <mbizon@freebox.fr>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Depends-on: 9f7853d760 ("powerpc/mm: Fix set_memory_*() against concurrent accesses")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cda2b44b55c96f9ac69fa92e68c01084ec9495c5.1640344012.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christophe Leroy
2021-12-24 11:07:40 +00:00
committed by Greg Kroah-Hartman
parent a29341e486
commit f4b0b5a0f3
3 changed files with 28 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
arch/powerpc/include/asm/set_memory.h
View File

@@ -6,6 +6,8 @@
#define SET_MEMORY_RW 1
#define SET_MEMORY_NX 2
#define SET_MEMORY_X 3
#define SET_MEMORY_NP 4 /* Set memory non present */
#define SET_MEMORY_P 5 /* Set memory present */
int change_memory_attr(unsigned long addr, int numpages, long action);
@@ -29,6 +31,14 @@ static inline int set_memory_x(unsigned long addr, int numpages)
return change_memory_attr(addr, numpages, SET_MEMORY_X);
}
int set_memory_attr(unsigned long addr, int numpages, pgprot_t prot);
static inline int set_memory_np(unsigned long addr, int numpages)
{
return change_memory_attr(addr, numpages, SET_MEMORY_NP);
}
static inline int set_memory_p(unsigned long addr, int numpages)
{
return change_memory_attr(addr, numpages, SET_MEMORY_P);
}
#endif