| Message ID | 1481417456-28826-3-git-send-email-alex.popov@linux.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Dec 11, 2016 at 1:50 AM, Alexander Popov <alex.popov@linux.com> wrote: > Subtract KASLR offset from the kernel addresses reported by kcov. > Tested on x86_64 and AArch64 (Hikey LeMaker). > > Signed-off-by: Alexander Popov <alex.popov@linux.com> > --- > kernel/kcov.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/kernel/kcov.c b/kernel/kcov.c > index 3cbb0c8..f8f3f4c 100644 > --- a/kernel/kcov.c > +++ b/kernel/kcov.c > @@ -14,6 +14,7 @@ > #include <linux/debugfs.h> > #include <linux/uaccess.h> > #include <linux/kcov.h> > +#include <asm/setup.h> > > /* > * kcov descriptor (one per opened debugfs file). > @@ -68,6 +69,11 @@ void notrace __sanitizer_cov_trace_pc(void) > if (mode == KCOV_MODE_TRACE) { > unsigned long *area; > unsigned long pos; > + unsigned long ip = _RET_IP_; > + > +#ifdef CONFIG_RANDOMIZE_BASE > + ip -= kaslr_offset(); > +#endif > > /* > * There is some code that runs in interrupts but for which > @@ -81,7 +87,7 @@ void notrace __sanitizer_cov_trace_pc(void) > /* The first word is number of subsequent PCs. */ > pos = READ_ONCE(area[0]) + 1; > if (likely(pos < t->kcov_size)) { > - area[pos] = _RET_IP_; > + area[pos] = ip; > WRITE_ONCE(area[0], pos); > } > } > -- > 2.7.4 Hi, I think generally this is the right thing to do. There are 2 pending patches for kcov by +Quentin (hopefully in mm): "kcov: add AFL-style tracing" "kcov: size of arena is now given in bytes" https://groups.google.com/forum/#!topic/syzkaller/gcqbIhKjGcY https://groups.google.com/d/msg/syzkaller/gcqbIhKjGcY/KQFryjBKCAAJ Your patch probably conflicts with them. Should you base them on top of these patches, so that Andrew can merge it without conflicts?
On 11.12.2016 12:32, Dmitry Vyukov wrote: > On Sun, Dec 11, 2016 at 1:50 AM, Alexander Popov <alex.popov@linux.com> wrote: >> Subtract KASLR offset from the kernel addresses reported by kcov. >> Tested on x86_64 and AArch64 (Hikey LeMaker). >> >> Signed-off-by: Alexander Popov <alex.popov@linux.com> >> --- >> kernel/kcov.c | 8 +++++++- >> 1 file changed, 7 insertions(+), 1 deletion(-) > > I think generally this is the right thing to do. > > There are 2 pending patches for kcov by +Quentin (hopefully in mm): > "kcov: add AFL-style tracing" > "kcov: size of arena is now given in bytes" > https://groups.google.com/forum/#!topic/syzkaller/gcqbIhKjGcY > https://groups.google.com/d/msg/syzkaller/gcqbIhKjGcY/KQFryjBKCAAJ > > Your patch probably conflicts with them. > Should you base them on top of these patches, so that Andrew can merge > it without conflicts? Excuse me, I can't find these patches in: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git git://git.cmpxchg.org/linux-mmots.git Could you point at the tree which I can rebase onto? Should I cherry-pick Quentin's patches manually? Best regards, Alexander
On Sun, Dec 11, 2016 at 10:37 PM, Alexander Popov <alex.popov@linux.com> wrote: > On 11.12.2016 12:32, Dmitry Vyukov wrote: >> On Sun, Dec 11, 2016 at 1:50 AM, Alexander Popov <alex.popov@linux.com> wrote: >>> Subtract KASLR offset from the kernel addresses reported by kcov. >>> Tested on x86_64 and AArch64 (Hikey LeMaker). >>> >>> Signed-off-by: Alexander Popov <alex.popov@linux.com> >>> --- >>> kernel/kcov.c | 8 +++++++- >>> 1 file changed, 7 insertions(+), 1 deletion(-) >> >> I think generally this is the right thing to do. >> >> There are 2 pending patches for kcov by +Quentin (hopefully in mm): >> "kcov: add AFL-style tracing" >> "kcov: size of arena is now given in bytes" >> https://groups.google.com/forum/#!topic/syzkaller/gcqbIhKjGcY >> https://groups.google.com/d/msg/syzkaller/gcqbIhKjGcY/KQFryjBKCAAJ >> >> Your patch probably conflicts with them. >> Should you base them on top of these patches, so that Andrew can merge >> it without conflicts? > > Excuse me, I can't find these patches in: > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git > git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git > git://git.cmpxchg.org/linux-mmots.git > > Could you point at the tree which I can rebase onto? > Should I cherry-pick Quentin's patches manually? Quentin, do you know destiny of your patches? They does not seem to be in mm tree.
On Mon, Dec 12, 2016 at 07:58:03AM +0100, Dmitry Vyukov wrote: > On Sun, Dec 11, 2016 at 10:37 PM, Alexander Popov <alex.popov@linux.com> wrote: > > On 11.12.2016 12:32, Dmitry Vyukov wrote: > >> On Sun, Dec 11, 2016 at 1:50 AM, Alexander Popov <alex.popov@linux.com> wrote: > >>> Subtract KASLR offset from the kernel addresses reported by kcov. > >>> Tested on x86_64 and AArch64 (Hikey LeMaker). > >>> > >>> Signed-off-by: Alexander Popov <alex.popov@linux.com> > >>> --- > >>> kernel/kcov.c | 8 +++++++- > >>> 1 file changed, 7 insertions(+), 1 deletion(-) > >> > >> I think generally this is the right thing to do. > >> > >> There are 2 pending patches for kcov by +Quentin (hopefully in mm): > >> "kcov: add AFL-style tracing" > >> "kcov: size of arena is now given in bytes" > >> https://groups.google.com/forum/#!topic/syzkaller/gcqbIhKjGcY > >> https://groups.google.com/d/msg/syzkaller/gcqbIhKjGcY/KQFryjBKCAAJ > >> > >> Your patch probably conflicts with them. > >> Should you base them on top of these patches, so that Andrew can merge > >> it without conflicts? > > > > Excuse me, I can't find these patches in: > > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git > > git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git > > git://git.cmpxchg.org/linux-mmots.git > > > > Could you point at the tree which I can rebase onto? > > Should I cherry-pick Quentin's patches manually? > > > Quentin, do you know destiny of your patches? They does not seem to be > in mm tree. Huh since apologies, looks like I messed up my filters and completely missed this thread. I was going to ask where my patches landed and who should take them... I'm happy to re-send them rebased on the mm tree if that's where they're going to land initially. Thanks, Quentin
diff --git a/kernel/kcov.c b/kernel/kcov.c index 3cbb0c8..f8f3f4c 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -14,6 +14,7 @@ #include <linux/debugfs.h> #include <linux/uaccess.h> #include <linux/kcov.h> +#include <asm/setup.h> /* * kcov descriptor (one per opened debugfs file). @@ -68,6 +69,11 @@ void notrace __sanitizer_cov_trace_pc(void) if (mode == KCOV_MODE_TRACE) { unsigned long *area; unsigned long pos; + unsigned long ip = _RET_IP_; + +#ifdef CONFIG_RANDOMIZE_BASE + ip -= kaslr_offset(); +#endif /* * There is some code that runs in interrupts but for which @@ -81,7 +87,7 @@ void notrace __sanitizer_cov_trace_pc(void) /* The first word is number of subsequent PCs. */ pos = READ_ONCE(area[0]) + 1; if (likely(pos < t->kcov_size)) { - area[pos] = _RET_IP_; + area[pos] = ip; WRITE_ONCE(area[0], pos); } }
Subtract KASLR offset from the kernel addresses reported by kcov. Tested on x86_64 and AArch64 (Hikey LeMaker). Signed-off-by: Alexander Popov <alex.popov@linux.com> --- kernel/kcov.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)