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![Christophe Leroy](/assets/img/avatar_default.png)
set_memory_attr() was implemented by commit4d1755b6a7
("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 commitc988cfd38e
("powerpc/32: use set_memory_attr()") but since commit9f7853d760
("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
44 lines
1.1 KiB
C
44 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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