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author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2020-09-02 09:59:45 +0530 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-09-15 22:13:21 +1000 |
commit | ac234524056da4e0c081f682da3ea25cdaab737a (patch) | |
tree | a7e2edb055bf396028cf1c39d107cf7537bc9033 | |
parent | fa725cc53d353110f39a9e5b9f60d6acb2c7ff49 (diff) | |
download | linux-stable-ac234524056da4e0c081f682da3ea25cdaab737a.tar.gz linux-stable-ac234524056da4e0c081f682da3ea25cdaab737a.tar.bz2 linux-stable-ac234524056da4e0c081f682da3ea25cdaab737a.zip |
selftests/powerpc: 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 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
-rw-r--r-- | tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c | 48 |
1 files 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); |