From: Thomas Gleixner ptdump_walk_pgd_level_checkwx() checks the kernel page table for WX pages, but does not check the PAGE_TABLE_ISOLATION user space page table. Restructure the code so that dmesg output is selected by an explicit argument and not implicit via checking the pgd argument for !NULL. Add the check for the user space page table. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org --- arch/x86/include/asm/pgtable.h | 1 + arch/x86/mm/debug_pagetables.c | 2 +- arch/x86/mm/dump_pagetables.c | 30 +++++++++++++++++++++++++----- 3 files changed, 27 insertions(+), 6 deletions(-) --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -28,6 +28,7 @@ extern pgd_t early_top_pgt[PTRS_PER_PGD] int __init __early_make_pgtable(unsigned long address, pmdval_t pmd); void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd); +void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd); void ptdump_walk_pgd_level_checkwx(void); #ifdef CONFIG_DEBUG_WX --- a/arch/x86/mm/debug_pagetables.c +++ b/arch/x86/mm/debug_pagetables.c @@ -5,7 +5,7 @@ static int ptdump_show(struct seq_file *m, void *v) { - ptdump_walk_pgd_level(m, NULL); + ptdump_walk_pgd_level_debugfs(m, NULL); return 0; } --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -459,7 +459,7 @@ static inline bool is_hypervisor_range(i } static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, - bool checkwx) + bool checkwx, bool dmesg) { #ifdef CONFIG_X86_64 pgd_t *start = (pgd_t *) &init_top_pgt; @@ -472,7 +472,7 @@ static void ptdump_walk_pgd_level_core(s if (pgd) { start = pgd; - st.to_dmesg = true; + st.to_dmesg = dmesg; } st.check_wx = checkwx; @@ -510,13 +510,33 @@ static void ptdump_walk_pgd_level_core(s void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd) { - ptdump_walk_pgd_level_core(m, pgd, false); + ptdump_walk_pgd_level_core(m, pgd, false, true); +} + +void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd) +{ + ptdump_walk_pgd_level_core(m, pgd, false, false); +} +EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs); + +static void ptdump_walk_user_pgd_level_checkwx(void) +{ +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pgd_t *pgd = (pgd_t *) &init_top_pgt; + + if (!static_cpu_has(X86_FEATURE_PTI)) + return; + + pr_info("x86/mm: Checking user space page tables\n"); + pgd = kernel_to_user_pgdp(pgd); + ptdump_walk_pgd_level_core(NULL, pgd, true, false); +#endif } -EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level); void ptdump_walk_pgd_level_checkwx(void) { - ptdump_walk_pgd_level_core(NULL, NULL, true); + ptdump_walk_pgd_level_core(NULL, NULL, true, false); + ptdump_walk_user_pgd_level_checkwx(); } static int __init pt_dump_init(void)