From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Date: Thu, 27 Jun 2019 09:59:40 +0000 (+0530)
Subject: powerpc/xmon: Fix disabling tracing while in xmon
X-Git-Tag: v5.3-rc1~94^2~123
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=aaf06665f7ea3ee9f9754e16c1a507a89f1de5b1;p=thirdparty%2Fkernel%2Flinux.git

powerpc/xmon: Fix disabling tracing while in xmon

Commit ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering
xmon") added code to disable recording trace entries while in xmon. The
commit introduced a variable 'tracing_enabled' to record if tracing was
enabled on xmon entry, and used this to conditionally enable tracing
during exit from xmon.

However, we are not checking the value of 'fromipi' variable in
xmon_core() when setting 'tracing_enabled'. Due to this, when secondary
cpus enter xmon, they will see tracing as being disabled already and
tracing won't be re-enabled on exit. Fix the same.

Fixes: ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering xmon")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 1b0149b2bb6c9..f1c4e1601b9d3 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -469,8 +469,10 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
 	local_irq_save(flags);
 	hard_irq_disable();
 
-	tracing_enabled = tracing_is_on();
-	tracing_off();
+	if (!fromipi) {
+		tracing_enabled = tracing_is_on();
+		tracing_off();
+	}
 
 	bp = in_breakpoint_table(regs->nip, &offset);
 	if (bp != NULL) {