[PATCH] powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#"

[Greg Kurz]

All these commands end up peeking into the PACA using the user originated
cpu id as an index. Check the cpu id is valid in order to prevent xmon to
crash. Instead of printing an error, this follows the same behavior as the
"lp s #" command : ignore the buggy cpu id parameter and fall back to the
#-less version of the command.

Signed-off-by: Greg Kurz <groug at kaod.org>
---
 arch/powerpc/xmon/xmon.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 80fbf8968f77..d3d6e044228e 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1248,7 +1248,7 @@ static int cpu_cmd(void)
 	unsigned long cpu, first_cpu, last_cpu;
 	int timeout;
 
-	if (!scanhex(&cpu)) {
+	if (!scanhex(&cpu) || cpu >= num_possible_cpus()) {
 		/* print cpus waiting or in xmon */
 		printf("cpus stopped:");
 		last_cpu = first_cpu = NR_CPUS;
@@ -2678,7 +2678,7 @@ static void dump_pacas(void)
 
 	termch = c;	/* Put c back, it wasn't 'a' */
 
-	if (scanhex(&num))
+	if (scanhex(&num) && num < num_possible_cpus())
 		dump_one_paca(num);
 	else
 		dump_one_paca(xmon_owner);
@@ -2751,7 +2751,7 @@ static void dump_xives(void)
 
 	termch = c;	/* Put c back, it wasn't 'a' */
 
-	if (scanhex(&num))
+	if (scanhex(&num) && num < num_possible_cpus())
 		dump_one_xive(num);
 	else
 		dump_one_xive(xmon_owner);