Introduce tests to cover simple scenarios where user is watching
memory which can be accessed by kernel as well. We also support
_MODE_EXACT with _SETHWDEBUG interface. Move those testcases outside
of _BP_RANGE condition. This will help to test _MODE_EXACT scenarios
when CONFIG_HAVE_HW_BREAKPOINT is not set, eg:
$ ./ptrace-hwbreak
...
PTRACE_SET_DEBUGREG, Kernel Access Userspace, len: 8: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, Kernel Access Userspace, len: 1: Ok
success: ptrace-hwbreak
Suggested-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-9-ravi.bangoria@linux.ibm.com
On the 8xx, signals are generated after executing the instruction. So
no need to manually single-step on 8xx. Also, 8xx __set_dabr()
currently ignores length and hardcodes the length to 8 bytes. So all
unaligned and 512 byte testcase will fail on 8xx. Ignore those
testcases on 8xx.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191017093204.7511-8-ravi.bangoria@linux.ibm.com
ptrace-hwbreak.c selftest is logically broken. On powerpc, when
watchpoint is created with ptrace, signals are generated before
executing the instruction and user has to manually singlestep the
instruction with watchpoint disabled, which selftest never does and
thus it keeps on getting the signal at the same instruction. If we fix
it, selftest fails because the logical connection between
tracer(parent) and tracee(child) is also broken. Rewrite the selftest
and add new tests for unaligned access.
With patch:
$ ./tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak
test: ptrace-hwbreak
tags: git_version:powerpc-5.3-4-224-g218b868240c7-dirty
PTRACE_SET_DEBUGREG, WO, len: 1: Ok
PTRACE_SET_DEBUGREG, WO, len: 2: Ok
PTRACE_SET_DEBUGREG, WO, len: 4: Ok
PTRACE_SET_DEBUGREG, WO, len: 8: Ok
PTRACE_SET_DEBUGREG, RO, len: 1: Ok
PTRACE_SET_DEBUGREG, RO, len: 2: Ok
PTRACE_SET_DEBUGREG, RO, len: 4: Ok
PTRACE_SET_DEBUGREG, RO, len: 8: Ok
PTRACE_SET_DEBUGREG, RW, len: 1: Ok
PTRACE_SET_DEBUGREG, RW, len: 2: Ok
PTRACE_SET_DEBUGREG, RW, len: 4: Ok
PTRACE_SET_DEBUGREG, RW, len: 8: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, WO, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RO, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RW, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, WO, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, RO, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, RW, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, DAR OUTSIDE, RW, len: 6: Ok
PPC_PTRACE_SETHWDEBUG, DAWR_MAX_LEN, RW, len: 512: Ok
success: ptrace-hwbreak
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191017093204.7511-6-ravi.bangoria@linux.ibm.com
This test the ptrace hw breakpoints via PTRACE_SET_DEBUGREG and
PPC_PTRACE_SETHWDEBUG. This test was use to find the bugs fixed by
these recent commits:
4f7c06e26e powerpc/ptrace: Fix setting 512B aligned breakpoints with PTRACE_SET_DEBUGREG
cd6ef7eebf powerpc/ptrace: Fix enforcement of DAWR constraints
Signed-off-by: Michael Neuling <mikey@neuling.org>
[mpe: Add SPDX tag, clang format it]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
