linux-kernel - [PATCH 4.12 033/106] powerpc/tm: Fix saving of TM SPRs in core dump

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170809164520.794277957@linuxfoundation.org>
Date:   Wed,  9 Aug 2017 09:52:17 -0700
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Gustavo Romero <gromero@...ux.vnet.ibm.com>,
        Cyril Bur <cyrilbur@...il.com>,
        Michael Ellerman <mpe@...erman.id.au>
Subject: [PATCH 4.12 033/106] powerpc/tm: Fix saving of TM SPRs in core dump

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gustavo Romero <gromero@...ux.vnet.ibm.com>

commit cd63f3cf1d59b7ad8419eba1cac8f9126e79cc43 upstream.

Currently flush_tmregs_to_thread() does not save the TM SPRs (TFHAR,
TFIAR, TEXASR) to the thread struct, unless the process is currently
inside a suspended transaction.

If the process is core dumping, and the TM SPRs have changed since the
last time the process was context switched, then we will save stale
values of the TM SPRs to the core dump.

Fix it by saving the live register state to the thread struct in that
case.

Fixes: 08e1c01d6aed ("powerpc/ptrace: Enable support for TM SPR state")
Signed-off-by: Gustavo Romero <gromero@...ux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyrilbur@...il.com>
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/powerpc/kernel/ptrace.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -127,12 +127,19 @@ static void flush_tmregs_to_thread(struc
 	 * If task is not current, it will have been flushed already to
 	 * it's thread_struct during __switch_to().
 	 *
-	 * A reclaim flushes ALL the state.
+	 * A reclaim flushes ALL the state or if not in TM save TM SPRs
+	 * in the appropriate thread structures from live.
 	 */
 
-	if (tsk == current && MSR_TM_SUSPENDED(mfmsr()))
-		tm_reclaim_current(TM_CAUSE_SIGNAL);
+	if (tsk != current)
+		return;
 
+	if (MSR_TM_SUSPENDED(mfmsr())) {
+		tm_reclaim_current(TM_CAUSE_SIGNAL);
+	} else {
+		tm_enable();
+		tm_save_sprs(&(tsk->thread));
+	}
 }
 #else
 static inline void flush_tmregs_to_thread(struct task_struct *tsk) { }