f222ab83df
set_memory_attr() was implemented by commit 4d1755b6a762 ("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 c988cfd38e48 ("powerpc/32:
use set_memory_attr()") but since commit 9f7853d7609d ("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: c988cfd38e48 ("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: 9f7853d7609d ("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
45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_SET_MEMORY_H
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#define _ASM_POWERPC_SET_MEMORY_H
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#define SET_MEMORY_RO 0
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#define SET_MEMORY_RW 1
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#define SET_MEMORY_NX 2
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#define SET_MEMORY_X 3
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#define SET_MEMORY_NP 4 /* Set memory non present */
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#define SET_MEMORY_P 5 /* Set memory present */
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int change_memory_attr(unsigned long addr, int numpages, long action);
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static inline int set_memory_ro(unsigned long addr, int numpages)
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{
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return change_memory_attr(addr, numpages, SET_MEMORY_RO);
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}
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static inline int set_memory_rw(unsigned long addr, int numpages)
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{
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return change_memory_attr(addr, numpages, SET_MEMORY_RW);
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}
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static inline int set_memory_nx(unsigned long addr, int numpages)
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{
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return change_memory_attr(addr, numpages, SET_MEMORY_NX);
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}
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static inline int set_memory_x(unsigned long addr, int numpages)
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{
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return change_memory_attr(addr, numpages, SET_MEMORY_X);
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}
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static inline int set_memory_np(unsigned long addr, int numpages)
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{
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return change_memory_attr(addr, numpages, SET_MEMORY_NP);
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}
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static inline int set_memory_p(unsigned long addr, int numpages)
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{
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return change_memory_attr(addr, numpages, SET_MEMORY_P);
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}
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#endif
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