linux-kernel - [PATCH 3/3] powerpc/32s: Define a MODULE area below kernel text all the time

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Message-Id: <a46dcdd39a9e80b012d86c294c4e5cd8d31665f3.1617283827.git.christophe.leroy@csgroup.eu>
Date:   Thu,  1 Apr 2021 13:30:43 +0000 (UTC)
From:   Christophe Leroy <christophe.leroy@...roup.eu>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>, jniethe5@...il.com
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH 3/3] powerpc/32s: Define a MODULE area below kernel text all
 the time

On book3s/32, the segment below kernel text is used for module
allocation when CONFIG_STRICT_KERNEL_RWX is defined.

In order to benefit from the powerpc specific module_alloc()
function which allocate modules with 32 Mbytes from
end of kernel text, use that segment below PAGE_OFFSET at all time.

Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
 arch/powerpc/Kconfig                         | 2 +-
 arch/powerpc/include/asm/book3s/32/pgtable.h | 2 --
 arch/powerpc/mm/book3s32/mmu.c               | 7 -------
 3 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c1344c05226c..15a91202d5c3 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -1219,7 +1219,7 @@ config TASK_SIZE_BOOL
 config TASK_SIZE
 	hex "Size of user task space" if TASK_SIZE_BOOL
 	default "0x80000000" if PPC_8xx
-	default "0xb0000000" if PPC_BOOK3S_32 && STRICT_KERNEL_RWX
+	default "0xb0000000" if PPC_BOOK3S_32
 	default "0xc0000000"
 endmenu
 
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 415ae29fa73a..83c65845a1a9 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -194,10 +194,8 @@ int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
 #define VMALLOC_END	ioremap_bot
 #endif
 
-#ifdef CONFIG_STRICT_KERNEL_RWX
 #define MODULES_END	ALIGN_DOWN(PAGE_OFFSET, SZ_256M)
 #define MODULES_VADDR	(MODULES_END - SZ_256M)
-#endif
 
 #ifndef __ASSEMBLY__
 #include <linux/sched.h>
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index a0db398b5c26..159930351d9f 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -184,17 +184,10 @@ static bool is_module_segment(unsigned long addr)
 {
 	if (!IS_ENABLED(CONFIG_MODULES))
 		return false;
-#ifdef MODULES_VADDR
 	if (addr < ALIGN_DOWN(MODULES_VADDR, SZ_256M))
 		return false;
 	if (addr > ALIGN(MODULES_END, SZ_256M) - 1)
 		return false;
-#else
-	if (addr < ALIGN_DOWN(VMALLOC_START, SZ_256M))
-		return false;
-	if (addr > ALIGN(VMALLOC_END, SZ_256M) - 1)
-		return false;
-#endif
 	return true;
 }
 
-- 
2.25.0