Messages in this thread | | | Subject | Re: [PATCH v6 8/8] powerpc/watchpoint/selftests: Tests for kernel accessing user memory | From | Rogerio Alves <> | Date | Thu, 17 Sep 2020 10:26:20 -0300 |
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On 9/2/20 1:29 AM, Ravi Bangoria wrote: > 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 out- > side 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> Tested-by: Rogerio Alves <rcardoso@linux.ibm.com> > --- > .../selftests/powerpc/ptrace/ptrace-hwbreak.c | 48 ++++++++++++++++++- > 1 file changed, 46 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c > index fc477dfe86a2..2e0d86e0687e 100644 > --- a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c > +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c > @@ -20,6 +20,8 @@ > #include <signal.h> > #include <sys/types.h> > #include <sys/wait.h> > +#include <sys/syscall.h> > +#include <linux/limits.h> > #include "ptrace.h" > > #define SPRN_PVR 0x11F > @@ -44,6 +46,7 @@ struct gstruct { > }; > static volatile struct gstruct gstruct __attribute__((aligned(512))); > > +static volatile char cwd[PATH_MAX] __attribute__((aligned(8))); > > static void get_dbginfo(pid_t child_pid, struct ppc_debug_info *dbginfo) > { > @@ -138,6 +141,9 @@ static void test_workload(void) > write_var(len); > } > > + /* PTRACE_SET_DEBUGREG, Kernel Access Userspace test */ > + syscall(__NR_getcwd, &cwd, PATH_MAX); > + > /* PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO test */ > write_var(1); > > @@ -150,6 +156,9 @@ static void test_workload(void) > else > read_var(1); > > + /* PPC_PTRACE_SETHWDEBUG, MODE_EXACT, Kernel Access Userspace test */ > + syscall(__NR_getcwd, &cwd, PATH_MAX); > + > /* PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, WO test */ > gstruct.a[rand() % A_LEN] = 'a'; > > @@ -293,6 +302,24 @@ static int test_set_debugreg(pid_t child_pid) > return 0; > } > > +static int test_set_debugreg_kernel_userspace(pid_t child_pid) > +{ > + unsigned long wp_addr = (unsigned long)cwd; > + char *name = "PTRACE_SET_DEBUGREG"; > + > + /* PTRACE_SET_DEBUGREG, Kernel Access Userspace test */ > + wp_addr &= ~0x7UL; > + wp_addr |= (1Ul << DABR_READ_SHIFT); > + wp_addr |= (1UL << DABR_WRITE_SHIFT); > + wp_addr |= (1UL << DABR_TRANSLATION_SHIFT); > + ptrace_set_debugreg(child_pid, wp_addr); > + ptrace(PTRACE_CONT, child_pid, NULL, 0); > + check_success(child_pid, name, "Kernel Access Userspace", wp_addr, 8); > + > + ptrace_set_debugreg(child_pid, 0); > + return 0; > +} > + > static void get_ppc_hw_breakpoint(struct ppc_hw_breakpoint *info, int type, > unsigned long addr, int len) > { > @@ -338,6 +365,22 @@ static void test_sethwdebug_exact(pid_t child_pid) > ptrace_delhwdebug(child_pid, wh); > } > > +static void test_sethwdebug_exact_kernel_userspace(pid_t child_pid) > +{ > + struct ppc_hw_breakpoint info; > + unsigned long wp_addr = (unsigned long)&cwd; > + char *name = "PPC_PTRACE_SETHWDEBUG, MODE_EXACT"; > + int len = 1; /* hardcoded in kernel */ > + int wh; > + > + /* PPC_PTRACE_SETHWDEBUG, MODE_EXACT, Kernel Access Userspace test */ > + get_ppc_hw_breakpoint(&info, PPC_BREAKPOINT_TRIGGER_WRITE, wp_addr, 0); > + wh = ptrace_sethwdebug(child_pid, &info); > + ptrace(PTRACE_CONT, child_pid, NULL, 0); > + check_success(child_pid, name, "Kernel Access Userspace", wp_addr, len); > + ptrace_delhwdebug(child_pid, wh); > +} > + > static void test_sethwdebug_range_aligned(pid_t child_pid) > { > struct ppc_hw_breakpoint info; > @@ -452,9 +495,10 @@ static void > run_tests(pid_t child_pid, struct ppc_debug_info *dbginfo, bool dawr) > { > test_set_debugreg(child_pid); > + test_set_debugreg_kernel_userspace(child_pid); > + test_sethwdebug_exact(child_pid); > + test_sethwdebug_exact_kernel_userspace(child_pid); > if (dbginfo->features & PPC_DEBUG_FEATURE_DATA_BP_RANGE) { > - test_sethwdebug_exact(child_pid); > - > test_sethwdebug_range_aligned(child_pid); > if (dawr || is_8xx) { > test_sethwdebug_range_unaligned(child_pid); >
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