From: Rogerio Alves <rcardoso@linux.ibm.com>
To: Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
mpe@ellerman.id.au, christophe.leroy@c-s.fr
Cc: mikey@neuling.org, jniethe5@gmail.com, pedromfc@linux.ibm.com,
linux-kernel@vger.kernel.org, paulus@samba.org,
rogealve@linux.ibm.com, naveen.n.rao@linux.vnet.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v6 3/8] powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N
Date: Thu, 17 Sep 2020 10:25:43 -0300 [thread overview]
Message-ID: <07c3e17e-df5a-884a-ac5d-f38cf40f2ad9@linux.ibm.com> (raw)
In-Reply-To: <20200902042945.129369-4-ravi.bangoria@linux.ibm.com>
On 9/2/20 1:29 AM, Ravi Bangoria wrote:
> 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@linux.ibm.com>
> Suggested-by: Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Rogerio Alves <rcardoso@linux.ibm.com>
> ---
> 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;
>
next prev parent reply other threads:[~2020-09-17 15:03 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 4:29 [PATCH v6 0/8] powerpc/watchpoint: Bug fixes plus new feature flag Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-02 4:29 ` [PATCH v6 1/8] powerpc/watchpoint: Fix quarword instruction handling on p10 predecessors Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:25 ` Rogerio Alves
2020-09-02 4:29 ` [PATCH v6 2/8] powerpc/watchpoint: Fix handling of vector instructions Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:25 ` Rogerio Alves
2020-09-02 4:29 ` [PATCH v6 3/8] powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:25 ` Rogerio Alves [this message]
2020-09-02 4:29 ` [PATCH v6 4/8] powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:25 ` Rogerio Alves
2020-09-02 4:29 ` [PATCH v6 5/8] powerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:25 ` Rogerio Alves
2020-09-02 4:29 ` [PATCH v6 6/8] powerpc/watchpoint: Add hw_len wherever missing Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:26 ` Rogerio Alves
2020-09-02 4:29 ` [PATCH v6 7/8] powerpc/watchpoint/ptrace: Introduce PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:26 ` Rogerio Alves
2020-09-02 4:29 ` [PATCH v6 8/8] powerpc/watchpoint/selftests: Tests for kernel accessing user memory Ravi Bangoria
2020-09-02 4:29 ` Ravi Bangoria
2020-09-17 13:26 ` Rogerio Alves
2020-09-17 11:27 ` [PATCH v6 0/8] powerpc/watchpoint: Bug fixes plus new feature flag Michael Ellerman
2020-09-17 11:27 ` Michael Ellerman
2020-09-17 13:24 ` Rogerio Alves
2020-09-18 8:31 ` Ravi Bangoria
2020-09-18 8:31 ` Ravi Bangoria
2020-09-18 10:50 ` Michael Ellerman
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