linux-kernel - [PATCH V7 2/8] powerpc, process: Add the function flush_tmregs_to

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: <1421219330-19984-3-git-send-email-khandual@linux.vnet.ibm.com>
Date:	Wed, 14 Jan 2015 12:38:44 +0530
From:	Anshuman Khandual <khandual@...ux.vnet.ibm.com>
To:	linux-kernel@...r.kernel.org, linuxppc-dev@...abs.org
Cc:	peterz@...radead.org, akpm@...ux-foundation.org,
	tglx@...utronix.de, james.hogan@...tec.com, avagin@...nvz.org,
	Paul.Clothier@...tec.com, palves@...hat.com, oleg@...hat.com,
	dhowells@...hat.com, davej@...hat.com, davem@...emloft.net,
	mikey@...ling.org, benh@...nel.crashing.org,
	sukadev@...ux.vnet.ibm.com, mpe@...erman.id.au,
	sam.bobroff@....ibm.com, kirjanov@...il.com,
	shuahkh@....samsung.com
Subject: [PATCH V7 2/8] powerpc, process: Add the function flush_tmregs_to_thread

This patch creates a function flush_tmregs_to_thread which
will then be used by subsequent patches in this series. The
function checks for self tracing ptrace interface attempts
while in the TM context and logs appropriate warning message.

Signed-off-by: Anshuman Khandual <khandual@...ux.vnet.ibm.com>
---
 arch/powerpc/include/asm/switch_to.h |  8 ++++++++
 arch/powerpc/kernel/process.c        | 20 ++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index 58abeda..23752a9 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -82,6 +82,14 @@ static inline void flush_spe_to_thread(struct task_struct *t)
 }
 #endif
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+extern void flush_tmregs_to_thread(struct task_struct *);
+#else
+static inline void flush_tmregs_to_thread(struct task_struct *t)
+{
+}
+#endif
+
 static inline void clear_task_ebb(struct task_struct *t)
 {
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index b4cc7be..a6f7ca5 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -745,6 +745,26 @@ void restore_tm_state(struct pt_regs *regs)
 #define __switch_to_tm(prev)
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+void flush_tmregs_to_thread(struct task_struct *tsk)
+{
+	/*
+	 * Process self tracing is not yet supported through
+	 * ptrace interface. Ptrace generic code should have
+	 * prevented this from happening in the first place.
+	 * Warn once here with the message, if some how it
+	 * is attempted.
+	 */
+	WARN_ONCE(tsk == current,
+		"Not expecting ptrace on self: TM regs may be incorrect\n");
+
+	/*
+	 * If task is not current, it should have been flushed
+	 * already to it's thread_struct during __switch_to().
+	 */
+}
+#endif
+
 struct task_struct *__switch_to(struct task_struct *prev,
 	struct task_struct *new)
 {
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/