This is a note to let you know that I've just added the patch titled
powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-watchpoint-ptrace-fix-sethwdebug-when-config.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit aabd62eeadeb16f096eff9f11f67db15e25be67a
Author: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
Date: Wed Sep 2 09:59:40 2020 +0530
powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N
[ Upstream commit 9b6b7c680cc20971444d9f836e49fc98848bcd0a ]
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 <pedromfc@xxxxxxxxxxxxx>
Suggested-by: Pedro Miraglia Franco de Carvalho <pedromfc@xxxxxxxxxxxxx>
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200902042945.129369-4-ravi.bangoria@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 8bd8d8de5c40b..a570782e954be 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;
brk.hw_len = DABR_MAX_LEN;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
