[PATCH v3] x86/pci: fix the function type for check_reserved_t

[Sami Tolvanen <samitolvanen@google.com>]

e820__mapped_all is passed as a callback to is_mmconf_reserved,
which expects a function of type:

typedef bool (*check_reserved_t)(u64 start, u64 end, unsigned type);

However, e820__mapped_all accepts enum e820_type as the last
argument and this type mismatch trips indirect call checking with
Clang's Control-Flow Integrity (CFI).

As is_mmconf_reserved only passes enum e820_type values for the
type argument, change the typedef and the unused type argument in
is_acpi_reserved to enum e820_type to fix the type mismatch.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/x86/pci/mmconfig-shared.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 6fa42e9c4e6f..234998f196d4 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -425,7 +425,7 @@ static acpi_status find_mboard_resource(acpi_handle handle, u32 lvl,
 	return AE_OK;
 }
 
-static bool is_acpi_reserved(u64 start, u64 end, unsigned not_used)
+static bool is_acpi_reserved(u64 start, u64 end, enum e820_type not_used)
 {
 	struct resource mcfg_res;
 
@@ -442,7 +442,7 @@ static bool is_acpi_reserved(u64 start, u64 end, unsigned not_used)
 	return mcfg_res.flags;
 }
 
-typedef bool (*check_reserved_t)(u64 start, u64 end, unsigned type);
+typedef bool (*check_reserved_t)(u64 start, u64 end, enum e820_type type);
 
 static bool __ref is_mmconf_reserved(check_reserved_t is_reserved,
 				     struct pci_mmcfg_region *cfg,

base-commit: b65054597872ce3aefbc6a666385eabdf9e288da
-- 
2.29.2.454.gaff20da3a2-goog