Message ID | 20210316031741.1004850-4-jniethe5@gmail.com (mailing list archive) |
---|---|
State | Changes Requested |
Headers | show |
Series | [v9,1/8] powerpc/mm: Implement set_memory() routines | expand |
Related | show |
Context | Check | Description |
---|---|---|
snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch powerpc/merge (0512161accb8b6f6dacc85d165350b1812ddcc33) |
snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch powerpc/next (fbda7904302499dd7ffc073a3c84eb7c9275db0a) |
snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch linus/master (1a4431a5db2bf800c647ee0ed87f2727b8d6c29c) |
snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch powerpc/fixes (eed5fae00593ab9d261a0c1ffc1bdb786a87a55a) |
snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch linux-next (1e28eed17697bcf343c6743f0028cc3b5dd88bf0) |
snowpatch_ozlabs/apply_patch | fail | Failed to apply to any branch |
Le 16/03/2021 à 04:17, Jordan Niethe a écrit : > From: Russell Currey <ruscur@russell.cc> > > Very rudimentary, just > > echo 1 > [debugfs]/check_wx_pages > > and check the kernel log. Useful for testing strict module RWX. > > Updated the Kconfig entry to reflect this. > > Also fixed a typo. Why not just perform the test everytime someone dumps kernel_page_tables ? > > Reviewed-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Russell Currey <ruscur@russell.cc> > Signed-off-by: Jordan Niethe <jniethe5@gmail.com> > --- > arch/powerpc/Kconfig.debug | 6 ++++-- > arch/powerpc/mm/ptdump/ptdump.c | 21 ++++++++++++++++++++- > 2 files changed, 24 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug > index ae084357994e..56e99e9a30d9 100644 > --- a/arch/powerpc/Kconfig.debug > +++ b/arch/powerpc/Kconfig.debug > @@ -371,7 +371,7 @@ config PPC_PTDUMP > If you are unsure, say N. > > config PPC_DEBUG_WX > - bool "Warn on W+X mappings at boot" > + bool "Warn on W+X mappings at boot & enable manual checks at runtime" > depends on PPC_PTDUMP && STRICT_KERNEL_RWX > help > Generate a warning if any W+X mappings are found at boot. > @@ -385,7 +385,9 @@ config PPC_DEBUG_WX > of other unfixed kernel bugs easier. > > There is no runtime or memory usage effect of this option > - once the kernel has booted up - it's a one time check. > + once the kernel has booted up, it only automatically checks once. > + > + Enables the "check_wx_pages" debugfs entry for checking at runtime. > > If in doubt, say "Y". > > diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c > index aca354fb670b..78497d57b66b 100644 > --- a/arch/powerpc/mm/ptdump/ptdump.c > +++ b/arch/powerpc/mm/ptdump/ptdump.c > @@ -4,7 +4,7 @@ > * > * This traverses the kernel pagetables and dumps the > * information about the used sections of memory to > - * /sys/kernel/debug/kernel_pagetables. > + * /sys/kernel/debug/kernel_page_tables. > * > * Derived from the arm64 implementation: > * Copyright (c) 2014, The Linux Foundation, Laura Abbott. > @@ -459,6 +459,25 @@ void ptdump_check_wx(void) > else > pr_info("Checked W+X mappings: passed, no W+X pages found\n"); > } > + > +static int check_wx_debugfs_set(void *data, u64 val) > +{ > + if (val != 1ULL) > + return -EINVAL; > + > + ptdump_check_wx(); > + > + return 0; > +} > + > +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); > + > +static int ptdump_check_wx_init(void) > +{ > + return debugfs_create_file("check_wx_pages", 0200, NULL, > + NULL, &check_wx_fops) ? 0 : -ENOMEM; > +} > +device_initcall(ptdump_check_wx_init); > #endif > > static int ptdump_init(void) >
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index ae084357994e..56e99e9a30d9 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -371,7 +371,7 @@ config PPC_PTDUMP If you are unsure, say N. config PPC_DEBUG_WX - bool "Warn on W+X mappings at boot" + bool "Warn on W+X mappings at boot & enable manual checks at runtime" depends on PPC_PTDUMP && STRICT_KERNEL_RWX help Generate a warning if any W+X mappings are found at boot. @@ -385,7 +385,9 @@ config PPC_DEBUG_WX of other unfixed kernel bugs easier. There is no runtime or memory usage effect of this option - once the kernel has booted up - it's a one time check. + once the kernel has booted up, it only automatically checks once. + + Enables the "check_wx_pages" debugfs entry for checking at runtime. If in doubt, say "Y". diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index aca354fb670b..78497d57b66b 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -4,7 +4,7 @@ * * This traverses the kernel pagetables and dumps the * information about the used sections of memory to - * /sys/kernel/debug/kernel_pagetables. + * /sys/kernel/debug/kernel_page_tables. * * Derived from the arm64 implementation: * Copyright (c) 2014, The Linux Foundation, Laura Abbott. @@ -459,6 +459,25 @@ void ptdump_check_wx(void) else pr_info("Checked W+X mappings: passed, no W+X pages found\n"); } + +static int check_wx_debugfs_set(void *data, u64 val) +{ + if (val != 1ULL) + return -EINVAL; + + ptdump_check_wx(); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); + +static int ptdump_check_wx_init(void) +{ + return debugfs_create_file("check_wx_pages", 0200, NULL, + NULL, &check_wx_fops) ? 0 : -ENOMEM; +} +device_initcall(ptdump_check_wx_init); #endif static int ptdump_init(void)