forked from Minki/linux
116fef6408
EFI is complicated enough that being able to view its pagetables is quite helpful. Rather than requiring users to fish it out of dmesg on an appropriately configured kernel, let users view it in debugfs as well. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/ba158a93f3250e6fca752cff2cfb1fcdd9f2b50c.1517414050.git.luto@kernel.org [ Fixed trivial whitespace damage and fixed missing export. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
147 lines
3.3 KiB
C
147 lines
3.3 KiB
C
#include <linux/debugfs.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <asm/pgtable.h>
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static int ptdump_show(struct seq_file *m, void *v)
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{
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ptdump_walk_pgd_level_debugfs(m, NULL, false);
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return 0;
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}
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static int ptdump_open(struct inode *inode, struct file *filp)
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{
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return single_open(filp, ptdump_show, NULL);
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}
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static const struct file_operations ptdump_fops = {
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.owner = THIS_MODULE,
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.open = ptdump_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int ptdump_show_curknl(struct seq_file *m, void *v)
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{
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if (current->mm->pgd) {
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down_read(¤t->mm->mmap_sem);
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ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, false);
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up_read(¤t->mm->mmap_sem);
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}
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return 0;
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}
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static int ptdump_open_curknl(struct inode *inode, struct file *filp)
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{
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return single_open(filp, ptdump_show_curknl, NULL);
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}
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static const struct file_operations ptdump_curknl_fops = {
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.owner = THIS_MODULE,
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.open = ptdump_open_curknl,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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#ifdef CONFIG_PAGE_TABLE_ISOLATION
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static struct dentry *pe_curusr;
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static int ptdump_show_curusr(struct seq_file *m, void *v)
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{
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if (current->mm->pgd) {
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down_read(¤t->mm->mmap_sem);
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ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, true);
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up_read(¤t->mm->mmap_sem);
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}
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return 0;
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}
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static int ptdump_open_curusr(struct inode *inode, struct file *filp)
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{
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return single_open(filp, ptdump_show_curusr, NULL);
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}
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static const struct file_operations ptdump_curusr_fops = {
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.owner = THIS_MODULE,
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.open = ptdump_open_curusr,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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#endif
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#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
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extern pgd_t *efi_pgd;
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static struct dentry *pe_efi;
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static int ptdump_show_efi(struct seq_file *m, void *v)
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{
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if (efi_pgd)
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ptdump_walk_pgd_level_debugfs(m, efi_pgd, false);
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return 0;
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}
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static int ptdump_open_efi(struct inode *inode, struct file *filp)
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{
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return single_open(filp, ptdump_show_efi, NULL);
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}
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static const struct file_operations ptdump_efi_fops = {
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.owner = THIS_MODULE,
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.open = ptdump_open_efi,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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#endif
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static struct dentry *dir, *pe_knl, *pe_curknl;
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static int __init pt_dump_debug_init(void)
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{
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dir = debugfs_create_dir("page_tables", NULL);
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if (!dir)
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return -ENOMEM;
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pe_knl = debugfs_create_file("kernel", 0400, dir, NULL,
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&ptdump_fops);
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if (!pe_knl)
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goto err;
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pe_curknl = debugfs_create_file("current_kernel", 0400,
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dir, NULL, &ptdump_curknl_fops);
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if (!pe_curknl)
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goto err;
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#ifdef CONFIG_PAGE_TABLE_ISOLATION
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pe_curusr = debugfs_create_file("current_user", 0400,
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dir, NULL, &ptdump_curusr_fops);
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if (!pe_curusr)
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goto err;
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#endif
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#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
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pe_efi = debugfs_create_file("efi", 0400, dir, NULL, &ptdump_efi_fops);
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if (!pe_efi)
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goto err;
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#endif
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return 0;
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err:
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debugfs_remove_recursive(dir);
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return -ENOMEM;
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}
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static void __exit pt_dump_debug_exit(void)
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{
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debugfs_remove_recursive(dir);
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}
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module_init(pt_dump_debug_init);
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module_exit(pt_dump_debug_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
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MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");
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