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authorKees Cook <keescook@chromium.org>2015-11-20 04:07:55 +0300
committerIngo Molnar <mingo@kernel.org>2015-11-23 12:50:13 +0300
commit8609d1b5daa36350e020e737946c40887af1743a (patch)
treeee0647a1fac4a9f752a5670fc68d48a059f0424e /arch/x86/mm/debug_pagetables.c
parent1ec218373b8ebda821aec00bb156a9c94fad9cd4 (diff)
downloadlinux-8609d1b5daa36350e020e737946c40887af1743a.tar.xz
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 <keescook@chromium.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/20151120010755.GA9060@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/debug_pagetables.c')
-rw-r--r--arch/x86/mm/debug_pagetables.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c
new file mode 100644
index 000000000000..b35ee86a9316
--- /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 <arjan@linux.intel.com>");
+MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");