2 files changed, 20 insertions, 12 deletions

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 5224f37338..a9f2b4af8f 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -61,26 +61,27 @@ static inline void no_context(struct pt_regs *regs, unsigned long addr)
 
 static inline void mm_fault_error(struct pt_regs *regs, unsigned long addr, vm_fault_t fault)
 {
+	if (!user_mode(regs)) {
+		no_context(regs, addr);
+		return;
+	}
+
 	if (fault & VM_FAULT_OOM) {
 		/*
 		 * We ran out of memory, call the OOM killer, and return the userspace
 		 * (which will retry the fault, or kill us if we got oom-killed).
 		 */
-		if (!user_mode(regs)) {
-			no_context(regs, addr);
-			return;
-		}
 		pagefault_out_of_memory();
 		return;
 	} else if (fault & (VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) {
 		/* Kernel mode? Handle exceptions or die */
-		if (!user_mode(regs)) {
-			no_context(regs, addr);
-			return;
-		}
 		do_trap(regs, SIGBUS, BUS_ADRERR, addr);
 		return;
+	} else if (fault & VM_FAULT_SIGSEGV) {
+		do_trap(regs, SIGSEGV, SEGV_MAPERR, addr);
+		return;
 	}
+
 	BUG();
 }
 
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index e3405e4b99..7e25606f85 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -233,8 +233,6 @@ static void __init setup_bootmem(void)
 	 */
 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
 
-	phys_ram_end = memblock_end_of_DRAM();
-
 	/*
 	 * Make sure we align the start of the memory on a PMD boundary so that
 	 * at worst, we map the linear mapping with PMD mappings.
@@ -250,6 +248,16 @@ static void __init setup_bootmem(void)
 		kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
 
 	/*
+	 * The size of the linear page mapping may restrict the amount of
+	 * usable RAM.
+	 */
+	if (IS_ENABLED(CONFIG_64BIT)) {
+		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
+		memblock_cap_memory_range(phys_ram_base,
+					  max_mapped_addr - phys_ram_base);
+	}
+
+	/*
 	 * Reserve physical address space that would be mapped to virtual
 	 * addresses greater than (void *)(-PAGE_SIZE) because:
 	 *  - This memory would overlap with ERR_PTR
@@ -265,6 +273,7 @@ static void __init setup_bootmem(void)
 		memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
 	}
 
+	phys_ram_end = memblock_end_of_DRAM();
 	min_low_pfn = PFN_UP(phys_ram_base);
 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
@@ -1289,8 +1298,6 @@ static void __init create_linear_mapping_page_table(void)
 		if (start <= __pa(PAGE_OFFSET) &&
 		    __pa(PAGE_OFFSET) < end)
 			start = __pa(PAGE_OFFSET);
-		if (end >= __pa(PAGE_OFFSET) + memory_limit)
-			end = __pa(PAGE_OFFSET) + memory_limit;
 
 		create_linear_mapping_range(start, end, 0);
 	}