ipmi_si: Fix crash when using hard-coded device

When excuting a command like:
  modprobe ipmi_si ports=0xffc0e3 type=bt
The system would get an oops.

The trouble here is that ipmi_si_hardcode_find_bmc() is called before
ipmi_si_platform_init(), but initialization of the hard-coded device
creates an IPMI platform device, which won't be initialized yet.

The real trouble is that hard-coded devices aren't created with
any device, and the fixup is done later.  So do it right, create the
hard-coded devices as normal platform devices.

This required adding some new resource types to the IPMI platform
code for passing information required by the hard-coded device
and adding some code to remove the hard-coded platform devices
on module removal.

To enforce the "hard-coded devices passed by the user take priority
over firmware devices" rule, some special code was added to check
and see if a hard-coded device already exists.

Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Yang Yingliang <yangyingliang@huawei.com>

1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index ae99d6a14789..abbd526626d5 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -1865,6 +1865,18 @@ int ipmi_si_add_smi(struct si_sm_io *io)
 	int rv = 0;
 	struct smi_info *new_smi, *dup;
 
+	/*
+	 * If the user gave us a hard-coded device at the same
+	 * address, they presumably want us to use it and not what is
+	 * in the firmware.
+	 */
+	if (io->addr_source != SI_HARDCODED &&
+	    ipmi_si_hardcode_match(io->addr_type, io->addr_data)) {
+		dev_info(io->dev,
+			 "Hard-coded device at this address already exists");
+		return -ENODEV;
+	}
+
 	if (!io->io_setup) {
 		if (io->addr_type == IPMI_IO_ADDR_SPACE) {
 			io->io_setup = ipmi_si_port_setup;
@@ -2097,7 +2109,7 @@ static int try_smi_init(struct smi_info *new_smi)
 	return rv;
 }
 
-static int init_ipmi_si(void)
+static int __init init_ipmi_si(void)
 {
 	struct smi_info *e;
 	enum ipmi_addr_src type = SI_INVALID;
@@ -2105,11 +2117,9 @@ static int init_ipmi_si(void)
 	if (initialized)
 		return 0;
 
-	pr_info("IPMI System Interface driver\n");
+	ipmi_hardcode_init();
 
-	/* If the user gave us a device, they presumably want us to use it */
-	if (!ipmi_si_hardcode_find_bmc())
-		goto do_scan;
+	pr_info("IPMI System Interface driver\n");
 
 	ipmi_si_platform_init();
 
@@ -2121,7 +2131,6 @@ static int init_ipmi_si(void)
 	   with multiple BMCs we assume that there will be several instances
 	   of a given type so if we succeed in registering a type then also
 	   try to register everything else of the same type */
-do_scan:
 	mutex_lock(&smi_infos_lock);
 	list_for_each_entry(e, &smi_infos, link) {
 		/* Try to register a device if it has an IRQ and we either
@@ -2307,6 +2316,8 @@ static void cleanup_ipmi_si(void)
 	list_for_each_entry_safe(e, tmp_e, &smi_infos, link)
 		cleanup_one_si(e);
 	mutex_unlock(&smi_infos_lock);
+
+	ipmi_si_hardcode_exit();
 }
 module_exit(cleanup_ipmi_si);