3 files changed, 71 insertions, 23 deletions

diff --git a/arch/riscv/mm/extable.c b/arch/riscv/mm/extable.c
index ddb7d3b99e89..05978f78579f 100644
--- a/arch/riscv/mm/extable.c
+++ b/arch/riscv/mm/extable.c
@@ -7,27 +7,65 @@
  */
 
 
+#include <linux/bitfield.h>
 #include <linux/extable.h>
 #include <linux/module.h>
 #include <linux/uaccess.h>
+#include <asm/asm-extable.h>
+#include <asm/ptrace.h>
 
-#if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I)
-int rv_bpf_fixup_exception(const struct exception_table_entry *ex, struct pt_regs *regs);
-#endif
+static inline unsigned long
+get_ex_fixup(const struct exception_table_entry *ex)
+{
+	return ((unsigned long)&ex->fixup + ex->fixup);
+}
+
+static bool ex_handler_fixup(const struct exception_table_entry *ex,
+			     struct pt_regs *regs)
+{
+	regs->epc = get_ex_fixup(ex);
+	return true;
+}
+
+static inline void regs_set_gpr(struct pt_regs *regs, unsigned int offset,
+				unsigned long val)
+{
+	if (unlikely(offset > MAX_REG_OFFSET))
+		return;
+
+	if (!offset)
+		*(unsigned long *)((unsigned long)regs + offset) = val;
+}
+
+static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
+					struct pt_regs *regs)
+{
+	int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+	int reg_zero = FIELD_GET(EX_DATA_REG_ZERO, ex->data);
+
+	regs_set_gpr(regs, reg_err, -EFAULT);
+	regs_set_gpr(regs, reg_zero, 0);
+
+	regs->epc = get_ex_fixup(ex);
+	return true;
+}
 
-int fixup_exception(struct pt_regs *regs)
+bool fixup_exception(struct pt_regs *regs)
 {
-	const struct exception_table_entry *fixup;
+	const struct exception_table_entry *ex;
 
-	fixup = search_exception_tables(regs->epc);
-	if (!fixup)
-		return 0;
+	ex = search_exception_tables(regs->epc);
+	if (!ex)
+		return false;
 
-#if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I)
-	if (regs->epc >= BPF_JIT_REGION_START && regs->epc < BPF_JIT_REGION_END)
-		return rv_bpf_fixup_exception(fixup, regs);
-#endif
+	switch (ex->type) {
+	case EX_TYPE_FIXUP:
+		return ex_handler_fixup(ex, regs);
+	case EX_TYPE_BPF:
+		return ex_handler_bpf(ex, regs);
+	case EX_TYPE_UACCESS_ERR_ZERO:
+		return ex_handler_uaccess_err_zero(ex, regs);
+	}
 
-	regs->epc = fixup->fixup;
-	return 1;
+	BUG();
 }
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index aa08dd2f8fae..4e9efbe46d5f 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -31,7 +31,7 @@ static void die_kernel_fault(const char *msg, unsigned long addr,
 
 	bust_spinlocks(0);
 	die(regs, "Oops");
-	do_exit(SIGKILL);
+	make_task_dead(SIGKILL);
 }
 
 static inline void no_context(struct pt_regs *regs, unsigned long addr)
@@ -235,7 +235,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 	 * only copy the information from the master page table,
 	 * nothing more.
 	 */
-	if (unlikely((addr >= VMALLOC_START) && (addr <= VMALLOC_END))) {
+	if (unlikely((addr >= VMALLOC_START) && (addr < VMALLOC_END))) {
 		vmalloc_fault(regs, code, addr);
 		return;
 	}
@@ -330,7 +330,7 @@ good_area:
 	if (fault_signal_pending(fault, regs))
 		return;
 
-	if (unlikely((fault & VM_FAULT_RETRY) && (flags & FAULT_FLAG_ALLOW_RETRY))) {
+	if (unlikely(fault & VM_FAULT_RETRY)) {
 		flags |= FAULT_FLAG_TRIED;
 
 		/*
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 24b2b8044602..0624c68331d8 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -187,10 +187,10 @@ static void __init setup_bootmem(void)
 
 
 	phys_ram_end = memblock_end_of_DRAM();
-#ifndef CONFIG_64BIT
 #ifndef CONFIG_XIP_KERNEL
 	phys_ram_base = memblock_start_of_DRAM();
 #endif
+#ifndef CONFIG_64BIT
 	/*
 	 * memblock allocator is not aware of the fact that last 4K bytes of
 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
@@ -367,7 +367,8 @@ static phys_addr_t __init alloc_pmd_late(uintptr_t va)
 	unsigned long vaddr;
 
 	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr);
+	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page(vaddr)));
+
 	return __pa(vaddr);
 }
 
@@ -812,13 +813,22 @@ static void __init reserve_crashkernel(void)
 	/*
 	 * Current riscv boot protocol requires 2MB alignment for
 	 * RV64 and 4MB alignment for RV32 (hugepage size)
+	 *
+	 * Try to alloc from 32bit addressible physical memory so that
+	 * swiotlb can work on the crash kernel.
 	 */
 	crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
-					       search_start, search_end);
+					       search_start,
+					       min(search_end, (unsigned long) SZ_4G));
 	if (crash_base == 0) {
-		pr_warn("crashkernel: couldn't allocate %lldKB\n",
-			crash_size >> 10);
-		return;
+		/* Try again without restricting region to 32bit addressible memory */
+		crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
+						search_start, search_end);
+		if (crash_base == 0) {
+			pr_warn("crashkernel: couldn't allocate %lldKB\n",
+				crash_size >> 10);
+			return;
+		}
 	}
 
 	pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",