linux/arch/powerpc/include/asm/set_memory.h

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_SET_MEMORY_H
#define _ASM_POWERPC_SET_MEMORY_H
#define SET_MEMORY_RO 0
#define SET_MEMORY_RW 1
#define SET_MEMORY_NX 2
#define SET_MEMORY_X 3
powerpc: Add set_memory_{p/np}() and remove set_memory_attr() 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
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#define SET_MEMORY_NP 4 /* Set memory non present */
#define SET_MEMORY_P 5 /* Set memory present */
#define SET_MEMORY_ROX 6
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int change_memory_attr(unsigned long addr, int numpages, long action);
static inline int __must_check set_memory_ro(unsigned long addr, int numpages)
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{
return change_memory_attr(addr, numpages, SET_MEMORY_RO);
}
static inline int __must_check set_memory_rw(unsigned long addr, int numpages)
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{
return change_memory_attr(addr, numpages, SET_MEMORY_RW);
}
static inline int __must_check set_memory_nx(unsigned long addr, int numpages)
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{
return change_memory_attr(addr, numpages, SET_MEMORY_NX);
}
static inline int __must_check set_memory_x(unsigned long addr, int numpages)
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{
return change_memory_attr(addr, numpages, SET_MEMORY_X);
}
static inline int __must_check set_memory_np(unsigned long addr, int numpages)
powerpc: Add set_memory_{p/np}() and remove set_memory_attr() 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
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{
return change_memory_attr(addr, numpages, SET_MEMORY_NP);
}
static inline int __must_check set_memory_p(unsigned long addr, int numpages)
powerpc: Add set_memory_{p/np}() and remove set_memory_attr() 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
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{
return change_memory_attr(addr, numpages, SET_MEMORY_P);
}
static inline int __must_check set_memory_rox(unsigned long addr, int numpages)
{
return change_memory_attr(addr, numpages, SET_MEMORY_ROX);
}
#define set_memory_rox set_memory_rox
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#endif