Re: [PATCH v6 8/8] powerpc/watchpoint/selftests: Tests for kernel accessing user memory
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
Signed-off-by: Ravi Bangoria
Tested-by: Rogerio Alves
---
.../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
#include
#include
+#include
+#include
#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, , 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, , 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)
+ 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(, PPC_BREAKPOINT_TRIGGER_WRITE, wp_addr, 0);
+ wh = ptrace_sethwdebug(child_pid, );
+ 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);
[PATCH v6 8/8] powerpc/watchpoint/selftests: Tests for kernel accessing user memory
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
Signed-off-by: Ravi Bangoria
---
.../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
#include
#include
+#include
+#include
#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, , 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, , 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)
+ 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(, PPC_BREAKPOINT_TRIGGER_WRITE, wp_addr, 0);
+ wh = ptrace_sethwdebug(child_pid, );
+ 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);
--
2.26.2
