@@ -650,11 +650,16 @@ static int compat_gpr_get(struct task_struct *target,
reg = task_pt_regs(target)->regs[idx];
}
- ret = copy_to_user(ubuf, ®, sizeof(reg));
- if (ret)
- break;
-
- ubuf += sizeof(reg);
+ if (kbuf) {
+ memcpy(kbuf, ®, sizeof(reg));
+ kbuf += sizeof(reg);
+ } else {
+ ret = copy_to_user(ubuf, ®, sizeof(reg));
+ if (ret)
+ break;
+
+ ubuf += sizeof(reg);
+ }
}
return ret;
@@ -684,11 +689,16 @@ static int compat_gpr_set(struct task_struct *target,
unsigned int idx = start + i;
compat_ulong_t reg;
- ret = copy_from_user(®, ubuf, sizeof(reg));
- if (ret)
- return ret;
+ if (kbuf) {
+ memcpy(®, kbuf, sizeof(reg));
+ kbuf += sizeof(reg);
+ } else {
+ ret = copy_from_user(®, ubuf, sizeof(reg));
+ if (ret)
+ return ret;
- ubuf += sizeof(reg);
+ ubuf += sizeof(reg);
+ }
switch (idx) {
case 15:
Currently core file of aarch32 process prstatus note has empty registers set. As result aarch32 core files create by V8 kernel are not very useful. It happens because compat_gpr_get and compat_gpr_set functions can copy registers values to/from either kbuf or ubuf. ELF core file collection function fill_thread_core_info calls compat_gpr_get with kbuf set and ubuf set to 0. But current compat_gpr_get and compat_gpr_set function handle copy to/from only ubuf case. Fix is to handle kbuf and ubuf as two separate cases in similar way as other functions like user_regset_copyout, user_regset_copyin do. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> --- arch/arm64/kernel/ptrace.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-)