treewide: Change list_sort to use const pointers

[ Upstream commit 4f0f586bf0c898233d8f316f471a21db2abd522d ]

list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.

Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

15 files changed, 28 insertions, 18 deletions

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index cb18cb5c51b1..d061bff5cc96 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1194,7 +1194,8 @@ static int __nfit_mem_init(struct acpi_nfit_desc *acpi_desc,
 	return 0;
 }
 
-static int nfit_mem_cmp(void *priv, struct list_head *_a, struct list_head *_b)
+static int nfit_mem_cmp(void *priv, const struct list_head *_a,
+		const struct list_head *_b)
 {
 	struct nfit_mem *a = container_of(_a, typeof(*a), list);
 	struct nfit_mem *b = container_of(_b, typeof(*b), list);
diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index cb73a5d6ea76..137a5dd880c2 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -558,7 +558,8 @@ static bool hmat_update_best(u8 type, u32 value, u32 *best)
 	return updated;
 }
 
-static int initiator_cmp(void *priv, struct list_head *a, struct list_head *b)
+static int initiator_cmp(void *priv, const struct list_head *a,
+			 const struct list_head *b)
 {
 	struct memory_initiator *ia;
 	struct memory_initiator *ib;
diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
index aaf31abe1c8f..7e1b136e71ae 100644
--- a/drivers/clk/keystone/sci-clk.c
+++ b/drivers/clk/keystone/sci-clk.c
@@ -503,8 +503,8 @@ static int ti_sci_scan_clocks_from_fw(struct sci_clk_provider *provider)
 
 #else
 
-static int _cmp_sci_clk_list(void *priv, struct list_head *a,
-			     struct list_head *b)
+static int _cmp_sci_clk_list(void *priv, const struct list_head *a,
+			     const struct list_head *b)
 {
 	struct sci_clk *ca = container_of(a, struct sci_clk, node);
 	struct sci_clk *cb = container_of(b, struct sci_clk, node);
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 511cde5c7fa6..0f99e5453f15 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1290,7 +1290,8 @@ EXPORT_SYMBOL(drm_mode_prune_invalid);
  * Negative if @lh_a is better than @lh_b, zero if they're equivalent, or
  * positive if @lh_b is better than @lh_a.
  */
-static int drm_mode_compare(void *priv, struct list_head *lh_a, struct list_head *lh_b)
+static int drm_mode_compare(void *priv, const struct list_head *lh_a,
+			    const struct list_head *lh_b)
 {
 	struct drm_display_mode *a = list_entry(lh_a, struct drm_display_mode, head);
 	struct drm_display_mode *b = list_entry(lh_b, struct drm_display_mode, head);
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c b/drivers/gpu/drm/i915/gt/intel_engine_user.c
index 34e6096f196e..da21d2a10cc9 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_user.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c
@@ -49,7 +49,8 @@ static const u8 uabi_classes[] = {
 	[VIDEO_ENHANCEMENT_CLASS] = I915_ENGINE_CLASS_VIDEO_ENHANCE,
 };
 
-static int engine_cmp(void *priv, struct list_head *A, struct list_head *B)
+static int engine_cmp(void *priv, const struct list_head *A,
+		      const struct list_head *B)
 {
 	const struct intel_engine_cs *a =
 		container_of((struct rb_node *)A, typeof(*a), uabi_node);
diff --git a/drivers/gpu/drm/i915/gvt/debugfs.c b/drivers/gpu/drm/i915/gvt/debugfs.c
index 62e6a14ad58e..9f1c209d9251 100644
--- a/drivers/gpu/drm/i915/gvt/debugfs.c
+++ b/drivers/gpu/drm/i915/gvt/debugfs.c
@@ -41,7 +41,7 @@ struct diff_mmio {
 
 /* Compare two diff_mmio items. */
 static int mmio_offset_compare(void *priv,
-	struct list_head *a, struct list_head *b)
+	const struct list_head *a, const struct list_head *b)
 {
 	struct diff_mmio *ma;
 	struct diff_mmio *mb;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 713770fb2b92..65e28c4cd4ce 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1075,7 +1075,8 @@ static int igt_ppgtt_shrink_boom(void *arg)
 	return exercise_ppgtt(arg, shrink_boom);
 }
 
-static int sort_holes(void *priv, struct list_head *A, struct list_head *B)
+static int sort_holes(void *priv, const struct list_head *A,
+		      const struct list_head *B)
 {
 	struct drm_mm_node *a = list_entry(A, typeof(*a), hole_stack);
 	struct drm_mm_node *b = list_entry(B, typeof(*b), hole_stack);
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 21ce2f9502c0..a78b60b62caf 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -394,8 +394,8 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 	return 0;
 }
 
-static int cmp_size_smaller_first(void *priv, struct list_head *a,
-				  struct list_head *b)
+static int cmp_size_smaller_first(void *priv, const struct list_head *a,
+				  const struct list_head *b)
 {
 	struct radeon_bo_list *la = list_entry(a, struct radeon_bo_list, tv.head);
 	struct radeon_bo_list *lb = list_entry(b, struct radeon_bo_list, tv.head);
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
index d399523206c7..29d71267af78 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
@@ -83,7 +83,8 @@ usnic_uiom_interval_node_alloc(long int start, long int last, int ref_cnt,
 	return interval;
 }
 
-static int interval_cmp(void *priv, struct list_head *a, struct list_head *b)
+static int interval_cmp(void *priv, const struct list_head *a,
+			const struct list_head *b)
 {
 	struct usnic_uiom_interval_node *node_a, *node_b;
 
diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c
index dd0e3bd50b94..3c0809095a31 100644
--- a/drivers/interconnect/qcom/bcm-voter.c
+++ b/drivers/interconnect/qcom/bcm-voter.c
@@ -39,7 +39,7 @@ struct bcm_voter {
 	u32 tcs_wait;
 };
 
-static int cmp_vcd(void *priv, struct list_head *a, struct list_head *b)
+static int cmp_vcd(void *priv, const struct list_head *a, const struct list_head *b)
 {
 	const struct qcom_icc_bcm *bcm_a =
 			list_entry(a, struct qcom_icc_bcm, list);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 39343479ac2a..c82953a3299e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -953,7 +953,8 @@ static void dispatch_bio_list(struct bio_list *tmp)
 		submit_bio_noacct(bio);
 }
 
-static int cmp_stripe(void *priv, struct list_head *a, struct list_head *b)
+static int cmp_stripe(void *priv, const struct list_head *a,
+		      const struct list_head *b)
 {
 	const struct r5pending_data *da = list_entry(a,
 				struct r5pending_data, sibling);
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index 6c1a23cb3e8c..202bf951e909 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -144,8 +144,8 @@ static void sram_free_partitions(struct sram_dev *sram)
 	}
 }
 
-static int sram_reserve_cmp(void *priv, struct list_head *a,
-					struct list_head *b)
+static int sram_reserve_cmp(void *priv, const struct list_head *a,
+					const struct list_head *b)
 {
 	struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
 	struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 5a9b2f1b1418..9c97628519e0 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3801,7 +3801,8 @@ out_unlock:
 	return ret;
 }
 
-static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
+static int ns_cmp(void *priv, const struct list_head *a,
+		const struct list_head *b)
 {
 	struct nvme_ns *nsa = container_of(a, struct nvme_ns, list);
 	struct nvme_ns *nsb = container_of(b, struct nvme_ns, list);
diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
index a40ed9e12b4b..fb96d37a135c 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-host.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -345,7 +345,8 @@ static int cdns_pcie_host_bar_config(struct cdns_pcie_rc *rc,
 	return 0;
 }
 
-static int cdns_pcie_host_dma_ranges_cmp(void *priv, struct list_head *a, struct list_head *b)
+static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a,
+					 const struct list_head *b)
 {
 	struct resource_entry *entry1, *entry2;
 
diff --git a/drivers/spi/spi-loopback-test.c b/drivers/spi/spi-loopback-test.c
index 89b91cdfb2a5..4d4f77a186a9 100644
--- a/drivers/spi/spi-loopback-test.c
+++ b/drivers/spi/spi-loopback-test.c
@@ -454,7 +454,8 @@ struct rx_ranges {
 	u8 *end;
 };
 
-static int rx_ranges_cmp(void *priv, struct list_head *a, struct list_head *b)
+static int rx_ranges_cmp(void *priv, const struct list_head *a,
+			 const struct list_head *b)
 {
 	struct rx_ranges *rx_a = list_entry(a, struct rx_ranges, list);
 	struct rx_ranges *rx_b = list_entry(b, struct rx_ranges, list);