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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2020-06-29 14:15:26 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-26 17:01:30 +0300 |
| commit | 6ca055322da8fe25ff9ac50db6f3b7b59b6f961c (patch) | |
| tree | 3de91cb2f36db895cd90d8294ae9b7e451426100 /arch/powerpc/include/asm/book3s/32 | |
| parent | f1a1f7a15eb0e13b84791ff2738b84e414501718 (diff) | |
| download | linux-6ca055322da8fe25ff9ac50db6f3b7b59b6f961c.tar.xz | |
powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWX
When STRICT_KERNEL_RWX is set, we want to set NX bit on vmalloc
segments. But modules require exec.
Use a dedicated segment for modules. There is not much space
above kernel, and we don't waste vmalloc space to do alignment.
Therefore, we take the segment before PAGE_OFFSET for modules.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eb8faba9148b6cf17c696ba776b4e8ee2f6313bf.1593428200.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/include/asm/book3s/32')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/pgtable.h | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h index 224912432821..36443cda8dcf 100644 --- a/arch/powerpc/include/asm/book3s/32/pgtable.h +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h @@ -184,17 +184,7 @@ int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot); */ #define VMALLOC_OFFSET (0x1000000) /* 16M */ -/* - * With CONFIG_STRICT_KERNEL_RWX, kernel segments are set NX. But when modules - * are used, NX cannot be set on VMALLOC space. So vmalloc VM space and linear - * memory shall not share segments. - */ -#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_MODULES) -#define VMALLOC_START ((ALIGN((long)high_memory, 256L << 20) + VMALLOC_OFFSET) & \ - ~(VMALLOC_OFFSET - 1)) -#else #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))) -#endif #ifdef CONFIG_KASAN_VMALLOC #define VMALLOC_END ALIGN_DOWN(ioremap_bot, PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT) @@ -202,6 +192,11 @@ 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> #include <linux/threads.h> |