diff options
| 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 | |
| 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')
| -rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/pgtable.h | 15 | ||||
| -rw-r--r-- | arch/powerpc/mm/ptdump/ptdump.c | 8 |
3 files changed, 14 insertions, 10 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a751edacf4bc..8c7656cc10eb 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -1213,6 +1213,7 @@ 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 "0xc0000000" endmenu 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> diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index 9d942136c7be..b2ed1ca4f254 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -74,6 +74,10 @@ struct addr_marker { static struct addr_marker address_markers[] = { { 0, "Start of kernel VM" }, +#ifdef MODULES_VADDR + { 0, "modules start" }, + { 0, "modules end" }, +#endif { 0, "vmalloc() Area" }, { 0, "vmalloc() End" }, #ifdef CONFIG_PPC64 @@ -353,6 +357,10 @@ static void populate_markers(void) #else address_markers[i++].start_address = TASK_SIZE; #endif +#ifdef MODULES_VADDR + address_markers[i++].start_address = MODULES_VADDR; + address_markers[i++].start_address = MODULES_END; +#endif address_markers[i++].start_address = VMALLOC_START; address_markers[i++].start_address = VMALLOC_END; #ifdef CONFIG_PPC64 |