Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull more arm64 fixes from Will Deacon:

 - Fix incorrect LDADD instruction encoding in our disassembly macros

 - Disable the broken ARM64_PSEUDO_NMI support for now

 - Add workaround for Cortex-A76 CPU erratum #1463225

 - Handle Cortex-A76/Neoverse-N1 erratum #1418040 w/ existing workaround

 - Fix IORT build failure if IOMMU_SUPPORT=n

 - Fix place-relative module relocation range checking and its
   interaction with KASLR

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: insn: Add BUILD_BUG_ON() for invalid masks
  arm64: insn: Fix ldadd instruction encoding
  arm64: Kconfig: Make ARM64_PSEUDO_NMI depend on BROKEN for now
  arm64: Handle erratum 1418040 as a superset of erratum 1188873
  arm64/module: deal with ambiguity in PRELxx relocation ranges
  ACPI/IORT: Fix build error when IOMMU_SUPPORT is disabled
  arm64/kernel: kaslr: reduce module randomization range to 2 GB
  arm64: errata: Add workaround for Cortex-A76 erratum #1463225
  arm64: Remove useless message during oops

1 files changed, 15 insertions, 3 deletions

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index f713e2fc4d75..f32359cffb01 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -56,7 +56,7 @@ void *module_alloc(unsigned long size)
 		 * can simply omit this fallback in that case.
 		 */
 		p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
-				module_alloc_base + SZ_4G, GFP_KERNEL,
+				module_alloc_base + SZ_2G, GFP_KERNEL,
 				PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
 				__builtin_return_address(0));
 
@@ -96,15 +96,27 @@ static int reloc_data(enum aarch64_reloc_op op, void *place, u64 val, int len)
 {
 	s64 sval = do_reloc(op, place, val);
 
+	/*
+	 * The ELF psABI for AArch64 documents the 16-bit and 32-bit place
+	 * relative relocations as having a range of [-2^15, 2^16) or
+	 * [-2^31, 2^32), respectively. However, in order to be able to detect
+	 * overflows reliably, we have to choose whether we interpret such
+	 * quantities as signed or as unsigned, and stick with it.
+	 * The way we organize our address space requires a signed
+	 * interpretation of 32-bit relative references, so let's use that
+	 * for all R_AARCH64_PRELxx relocations. This means our upper
+	 * bound for overflow detection should be Sxx_MAX rather than Uxx_MAX.
+	 */
+
 	switch (len) {
 	case 16:
 		*(s16 *)place = sval;
-		if (sval < S16_MIN || sval > U16_MAX)
+		if (sval < S16_MIN || sval > S16_MAX)
 			return -ERANGE;
 		break;
 	case 32:
 		*(s32 *)place = sval;
-		if (sval < S32_MIN || sval > U32_MAX)
+		if (sval < S32_MIN || sval > S32_MAX)
 			return -ERANGE;
 		break;
 	case 64: