[PATCH v3 1/2] powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N

From: Ravi Bangoria
Date: Wed Aug 05 2020 - 02:28:33 EST


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.

Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@xxxxxxxxxx>
Suggested-by: Pedro Miraglia Franco de Carvalho <pedromfc@xxxxxxxxxx>
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
---
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..bf94ab837735 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_USER;
brk.len = DABR_MAX_LEN;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
brk.type |= HW_BRK_TYPE_READ;
--
2.26.2