| Message ID | CAKv+Gu-vxhJRUMK7sqv1saw+wkQRD5xFydpgTLbKgWhoNj5LmA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Feb 09, 2016 at 11:03:01AM +0100, Ard Biesheuvel wrote: > On 8 February 2016 at 19:13, Catalin Marinas <catalin.marinas@arm.com> wrote: > > On Mon, Feb 08, 2016 at 11:12:12AM +0100, Ard Biesheuvel wrote: > >> This adds the option to randomize the module region independently from the > >> core kernel, and enables it by default. This makes it less likely that the > >> location of core kernel data structures can be determined by an adversary, > >> but causes all function calls from modules into the core kernel to be > >> resolved via entries in the module PLTs. > >> > >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > >> --- > >> arch/arm64/Kconfig | 15 ++++++++ > >> arch/arm64/include/asm/module.h | 6 ++++ > >> arch/arm64/kernel/kaslr.c | 36 +++++++++++++++----- > >> arch/arm64/kernel/module.c | 9 ++--- > >> 4 files changed, 50 insertions(+), 16 deletions(-) > > > > With this patch I get an unhandled paging request, coming from > > kernel/module.c:2982 (the memset). The PC is wrongly attributed but it's > > in arch/arm64/lib/memset.S: > > > > This was due to a thinko in kaslr_early_init(). Folding the following > hunk will fix it (or I can resend the patch if you prefer) > > -------8<---------- > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c > index f8ad30160026..d7eba99ab140 100644 > --- a/arch/arm64/kernel/kaslr.c > +++ b/arch/arm64/kernel/kaslr.c > @@ -82,6 +82,12 @@ u64 __init kaslr_early_init(u64 dt_phys) > int size; > > /* > + * Set a reasonable default for module_alloc_base in case > + * we end up running with KASLR disabled. > + */ > + module_alloc_base = (u64)_etext - MODULES_VSIZE; > + > + /* > * Try to map the FDT early. If this fails, we simply bail, > * and proceed with KASLR disabled. We will make another > * attempt at mapping the FDT in setup_machine() > -------8<---------- I'll fold the hunk in and give it a try. Thanks. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c index f8ad30160026..d7eba99ab140 100644 --- a/arch/arm64/kernel/kaslr.c +++ b/arch/arm64/kernel/kaslr.c @@ -82,6 +82,12 @@ u64 __init kaslr_early_init(u64 dt_phys) int size; /* + * Set a reasonable default for module_alloc_base in case + * we end up running with KASLR disabled. + */ + module_alloc_base = (u64)_etext - MODULES_VSIZE; + + /* * Try to map the FDT early. If this fails, we simply bail, * and proceed with KASLR disabled. We will make another * attempt at mapping the FDT in setup_machine()