Commit-ID: 8609d1b5daa36350e020e737946c40887af1743a Gitweb: http://git.kernel.org/tip/8609d1b5daa36350e020e737946c40887af1743a Author: Kees Cook <keesc...@chromium.org> AuthorDate: Thu, 19 Nov 2015 17:07:55 -0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 23 Nov 2015 10:50:13 +0100
x86/mm: Turn CONFIG_X86_PTDUMP into a module Being able to examine page tables is handy, so make this a module that can be loaded as needed. Signed-off-by: Kees Cook <keesc...@chromium.org> Cc: Andrey Ryabinin <ryabinin....@gmail.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Boris Ostrovsky <boris.ostrov...@oracle.com> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephen Smalley <s...@tycho.nsa.gov> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Toshi Kani <toshi.k...@hpe.com> Cc: Vladimir Murzin <vladimir.mur...@arm.com> Cc: Will Deacon <will.dea...@arm.com> Link: http://lkml.kernel.org/r/20151120010755.ga9...@www.outflux.net Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/Kconfig.debug | 2 +- arch/x86/mm/Makefile | 1 + arch/x86/mm/debug_pagetables.c | 46 ++++++++++++++++++++++++++++++++++++++++++ arch/x86/mm/dump_pagetables.c | 34 ++----------------------------- 4 files changed, 50 insertions(+), 33 deletions(-) diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 137dfa9..110253c 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -69,7 +69,7 @@ config X86_PTDUMP_CORE def_bool n config X86_PTDUMP - bool "Export kernel pagetable layout to userspace via debugfs" + tristate "Export kernel pagetable layout to userspace via debugfs" depends on DEBUG_KERNEL select DEBUG_FS select X86_PTDUMP_CORE diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 65c47fd..f9d38a4 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_X86_PTDUMP_CORE) += dump_pagetables.o +obj-$(CONFIG_X86_PTDUMP) += debug_pagetables.o obj-$(CONFIG_HIGHMEM) += highmem_32.o diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c new file mode 100644 index 0000000..b35ee86 --- /dev/null +++ b/arch/x86/mm/debug_pagetables.c @@ -0,0 +1,46 @@ +#include <linux/debugfs.h> +#include <linux/module.h> +#include <linux/seq_file.h> +#include <asm/pgtable.h> + +static int ptdump_show(struct seq_file *m, void *v) +{ + ptdump_walk_pgd_level(m, NULL); + return 0; +} + +static int ptdump_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, ptdump_show, NULL); +} + +static const struct file_operations ptdump_fops = { + .owner = THIS_MODULE, + .open = ptdump_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static struct dentry *pe; + +static int __init pt_dump_debug_init(void) +{ + pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL, + &ptdump_fops); + if (!pe) + return -ENOMEM; + + return 0; +} + +static void __exit pt_dump_debug_exit(void) +{ + debugfs_remove_recursive(pe); +} + +module_init(pt_dump_debug_init); +module_exit(pt_dump_debug_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arjan van de Ven <ar...@linux.intel.com>"); +MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables"); diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index a035c2a..90a1dc0 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -426,38 +426,15 @@ void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd) { ptdump_walk_pgd_level_core(m, pgd, false); } +EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level); void ptdump_walk_pgd_level_checkwx(void) { ptdump_walk_pgd_level_core(NULL, NULL, true); } -#ifdef CONFIG_X86_PTDUMP -static int ptdump_show(struct seq_file *m, void *v) +static int __init pt_dump_init(void) { - ptdump_walk_pgd_level(m, NULL); - return 0; -} - -static int ptdump_open(struct inode *inode, struct file *filp) -{ - return single_open(filp, ptdump_show, NULL); -} - -static const struct file_operations ptdump_fops = { - .open = ptdump_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; -#endif - -static int pt_dump_init(void) -{ -#ifdef CONFIG_X86_PTDUMP - struct dentry *pe; -#endif - #ifdef CONFIG_X86_32 /* Not a compile-time constant on x86-32 */ address_markers[VMALLOC_START_NR].start_address = VMALLOC_START; @@ -468,13 +445,6 @@ static int pt_dump_init(void) address_markers[FIXADDR_START_NR].start_address = FIXADDR_START; #endif -#ifdef CONFIG_X86_PTDUMP - pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL, - &ptdump_fops); - if (!pe) - return -ENOMEM; -#endif - return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
