| Message ID | 20190613111335.7645-5-cristian.marussi@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add arm64/signal initial kselftest support | expand |
On Thu, Jun 13, 2019 at 12:13:26PM +0100, Cristian Marussi wrote: > Added a simple mangle testcase which messes with the ucontext_t > from within the sig_handler, trying to badly modify the PC to point > toward Kernel land. > Expects SIGSEGV on test PASS. > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > --- > .../arm64/signal/testcases/.gitignore | 1 + > .../signal/testcases/mangle_pc_invalid.c | 24 +++++++++++++++++++ > 2 files changed, 25 insertions(+) > create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c > > diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore > index 7f7414d241f2..a87fb0f0d2cf 100644 > --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore > +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore > @@ -1 +1,2 @@ > mangle_sp_misaligned > +mangle_pc_invalid > diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c > new file mode 100644 > index 000000000000..0024032528bc > --- /dev/null > +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c > @@ -0,0 +1,24 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* Copyright (C) 2019 ARM Limited */ > + > +#include "test_signals_utils.h" > +#include "testcases.h" > + > +static int mangle_invalid_pc_run(struct tdescr *td, siginfo_t *si, > + ucontext_t *uc) > +{ > + ASSERT_GOOD_CONTEXT(uc); > + > + uc->uc_mcontext.pc = 0xffffffffcccccccc; Similarly to the previous test, I don't think this is testing the sigreturn behaviour: the kernel just restores the bogus PC value and returns to userspace. We then rely on the architecture to generate a prefetch abort when trying to fetch from the bogus PC. Am I missing anything? Could we have a test that points SP to kernel memory and the calls sigreturn: there is a real behaviour to test there: we must not be able to trick the kernel into interpreting kernel memory as a signal frame. [...] Cheers --Dave
diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore index 7f7414d241f2..a87fb0f0d2cf 100644 --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore @@ -1 +1,2 @@ mangle_sp_misaligned +mangle_pc_invalid diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c new file mode 100644 index 000000000000..0024032528bc --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2019 ARM Limited */ + +#include "test_signals_utils.h" +#include "testcases.h" + +static int mangle_invalid_pc_run(struct tdescr *td, siginfo_t *si, + ucontext_t *uc) +{ + ASSERT_GOOD_CONTEXT(uc); + + uc->uc_mcontext.pc = 0xffffffffcccccccc; + + return 1; +} + +struct tdescr tde = { + .sanity_disabled = true, + .name = "MANGLE_PC_INVALID", + .descr = "Mangling uc_mcontext with INVALID PC", + .sig_trig = SIGUSR1, + .sig_ok = SIGSEGV, + .run = mangle_invalid_pc_run, +};
Added a simple mangle testcase which messes with the ucontext_t from within the sig_handler, trying to badly modify the PC to point toward Kernel land. Expects SIGSEGV on test PASS. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- .../arm64/signal/testcases/.gitignore | 1 + .../signal/testcases/mangle_pc_invalid.c | 24 +++++++++++++++++++ 2 files changed, 25 insertions(+) create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c