# \[PATCH v6 3/8\] powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG\_HAVE\_HW\_BREAKPOINT=N - From: Ravi Bangoria \ - Date: 2020-09-02 04:30:27 - List: linuxppc-dev - Page: https://ratatoskr.run/linuxppc-dev/2020/09/6091186 - Thread: https://ratatoskr.run/linuxppc-dev/2020/09/6091184/t.md ```text When kernel is compiled with CONFIG_HAVE_HW_BREAKPOINT=N, user can still create watchpoint using PPC_PTRACE_SETHWDEBUG, with limited functionalities. But, such watchpoints are never firing because of the missing privilege settings. Fix that. It's safe to set HW_BRK_TYPE_PRIV_ALL because we don't really leak any kernel address in signal info. Setting HW_BRK_TYPE_PRIV_ALL will also help to find scenarios when kernel accesses user memory. Reported-by: Pedro Miraglia Franco de Carvalho Suggested-by: Pedro Miraglia Franco de Carvalho Signed-off-by: Ravi Bangoria --- arch/powerpc/kernel/ptrace/ptrace-noadv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c index 697c7e4b5877..57a0ab822334 100644 --- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c +++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c @@ -217,7 +217,7 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf return -EIO; brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE); - brk.type = HW_BRK_TYPE_TRANSLATE; + brk.type = HW_BRK_TYPE_TRANSLATE | HW_BRK_TYPE_PRIV_ALL; brk.len = DABR_MAX_LEN; if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ) brk.type |= HW_BRK_TYPE_READ; -- 2.26.2 ```