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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2016-07-05 05:03:59 (GMT)
committerMichael Ellerman <mpe@ellerman.id.au>2016-07-21 08:59:21 (GMT)
commit84b62c72faa197a5c9b75ee93527add31695fb32 (patch)
tree2b17401ea116e80f5c36b228d349e48dc7f9c9af /arch/powerpc
parent7025776ed1ebdfa1959932e7a4662c2f88607df0 (diff)
downloadlinux-84b62c72faa197a5c9b75ee93527add31695fb32.tar.xz
powerpc: Ensure that ppc_md is empty before probing for machine type
Anything in there will be overwritten, so it helps catching nasty bugs if we check that it's indeed full of NULL's before we do so. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/setup-common.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 2a3564c..b8ee1c8 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -575,6 +575,7 @@ void probe_machine(void)
{
extern struct machdep_calls __machine_desc_start;
extern struct machdep_calls __machine_desc_end;
+ unsigned int i;
/*
* Iterate all ppc_md structures until we find the proper
@@ -582,6 +583,17 @@ void probe_machine(void)
*/
DBG("Probing machine type ...\n");
+ /*
+ * Check ppc_md is empty, if not we have a bug, ie, we setup an
+ * entry before probe_machine() which will be overwritten
+ */
+ for (i = 0; i < (sizeof(ppc_md) / sizeof(void *)); i++) {
+ if (((void **)&ppc_md)[i]) {
+ printk(KERN_ERR "Entry %d in ppc_md non empty before"
+ " machine probe !\n", i);
+ }
+ }
+
for (machine_id = &__machine_desc_start;
machine_id < &__machine_desc_end;
machine_id++) {