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authorArnd Bergmann <arnd@arndb.de>2019-08-29 18:23:51 +0300
committerArnd Bergmann <arnd@arndb.de>2019-08-29 18:23:52 +0300
commit34614c30bf16d84392f8cc0173461b99e95a7b75 (patch)
tree44086f3e340f954a9ad6b5a65a003828cca9f1a7 /lib
parent305cd70ec311be420cc9154e77427dd9aaa0b7bc (diff)
parent10e62b47973b0b0ceda076255bcb147b83e20517 (diff)
downloadlinux-34614c30bf16d84392f8cc0173461b99e95a7b75.tar.xz
Merge tag 'hisi-fixes-for-5.3' of git://github.com/hisilicon/linux-hisi into arm/fixes
Hisilicon fixes for v5.3-rc - Fixed RCU usage in logical PIO - Added a function to unregister a logical PIO range in logical PIO to support the fixes in the hisi-lpc driver - Fixed and optimized hisi-lpc driver to avoid potential use-after-free and driver unbind crash * tag 'hisi-fixes-for-5.3' of git://github.com/hisilicon/linux-hisi: bus: hisi_lpc: Add .remove method to avoid driver unbind crash bus: hisi_lpc: Unregister logical PIO range to avoid potential use-after-free lib: logic_pio: Add logic_pio_unregister_range() lib: logic_pio: Avoid possible overlap for unregistering regions lib: logic_pio: Fix RCU usage Link: https://lore.kernel.org/r/5D562335.7000902@hisilicon.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'lib')
-rw-r--r--lib/logic_pio.c73
1 files changed, 54 insertions, 19 deletions
diff --git a/lib/logic_pio.c b/lib/logic_pio.c
index feea48fd1a0d..905027574e5d 100644
--- a/lib/logic_pio.c
+++ b/lib/logic_pio.c
@@ -35,7 +35,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
struct logic_pio_hwaddr *range;
resource_size_t start;
resource_size_t end;
- resource_size_t mmio_sz = 0;
+ resource_size_t mmio_end = 0;
resource_size_t iio_sz = MMIO_UPPER_LIMIT;
int ret = 0;
@@ -46,7 +46,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
end = new_range->hw_start + new_range->size;
mutex_lock(&io_range_mutex);
- list_for_each_entry_rcu(range, &io_range_list, list) {
+ list_for_each_entry(range, &io_range_list, list) {
if (range->fwnode == new_range->fwnode) {
/* range already there */
goto end_register;
@@ -56,7 +56,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
/* for MMIO ranges we need to check for overlap */
if (start >= range->hw_start + range->size ||
end < range->hw_start) {
- mmio_sz += range->size;
+ mmio_end = range->io_start + range->size;
} else {
ret = -EFAULT;
goto end_register;
@@ -69,16 +69,16 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
/* range not registered yet, check for available space */
if (new_range->flags == LOGIC_PIO_CPU_MMIO) {
- if (mmio_sz + new_range->size - 1 > MMIO_UPPER_LIMIT) {
+ if (mmio_end + new_range->size - 1 > MMIO_UPPER_LIMIT) {
/* if it's too big check if 64K space can be reserved */
- if (mmio_sz + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
+ if (mmio_end + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
ret = -E2BIG;
goto end_register;
}
new_range->size = SZ_64K;
pr_warn("Requested IO range too big, new size set to 64K\n");
}
- new_range->io_start = mmio_sz;
+ new_range->io_start = mmio_end;
} else if (new_range->flags == LOGIC_PIO_INDIRECT) {
if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) {
ret = -E2BIG;
@@ -99,6 +99,20 @@ end_register:
}
/**
+ * logic_pio_unregister_range - unregister a logical PIO range for a host
+ * @range: pointer to the IO range which has been already registered.
+ *
+ * Unregister a previously-registered IO range node.
+ */
+void logic_pio_unregister_range(struct logic_pio_hwaddr *range)
+{
+ mutex_lock(&io_range_mutex);
+ list_del_rcu(&range->list);
+ mutex_unlock(&io_range_mutex);
+ synchronize_rcu();
+}
+
+/**
* find_io_range_by_fwnode - find logical PIO range for given FW node
* @fwnode: FW node handle associated with logical PIO range
*
@@ -108,26 +122,38 @@ end_register:
*/
struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
{
- struct logic_pio_hwaddr *range;
+ struct logic_pio_hwaddr *range, *found_range = NULL;
+ rcu_read_lock();
list_for_each_entry_rcu(range, &io_range_list, list) {
- if (range->fwnode == fwnode)
- return range;
+ if (range->fwnode == fwnode) {
+ found_range = range;
+ break;
+ }
}
- return NULL;
+ rcu_read_unlock();
+
+ return found_range;
}
/* Return a registered range given an input PIO token */
static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
{
- struct logic_pio_hwaddr *range;
+ struct logic_pio_hwaddr *range, *found_range = NULL;
+ rcu_read_lock();
list_for_each_entry_rcu(range, &io_range_list, list) {
- if (in_range(pio, range->io_start, range->size))
- return range;
+ if (in_range(pio, range->io_start, range->size)) {
+ found_range = range;
+ break;
+ }
}
- pr_err("PIO entry token %lx invalid\n", pio);
- return NULL;
+ rcu_read_unlock();
+
+ if (!found_range)
+ pr_err("PIO entry token 0x%lx invalid\n", pio);
+
+ return found_range;
}
/**
@@ -180,14 +206,23 @@ unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
{
struct logic_pio_hwaddr *range;
+ rcu_read_lock();
list_for_each_entry_rcu(range, &io_range_list, list) {
if (range->flags != LOGIC_PIO_CPU_MMIO)
continue;
- if (in_range(addr, range->hw_start, range->size))
- return addr - range->hw_start + range->io_start;
+ if (in_range(addr, range->hw_start, range->size)) {
+ unsigned long cpuaddr;
+
+ cpuaddr = addr - range->hw_start + range->io_start;
+
+ rcu_read_unlock();
+ return cpuaddr;
+ }
}
- pr_err("addr %llx not registered in io_range_list\n",
- (unsigned long long) addr);
+ rcu_read_unlock();
+
+ pr_err("addr %pa not registered in io_range_list\n", &addr);
+
return ~0UL;
}