Merge tag 'riscv-for-linus-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - A revert for the mmap() change that ties the allocation range to the
   hint adress, as what we tried to do ended up regressing on other
   userspace workloads.

 - A fix to avoid a kernel memory leak when emulating misaligned
   accesses from userspace.

 - A Kconfig fix for toolchain vector detection, which now correctly
   detects vector support on toolchains where the V extension depends on
   the M extension.

 - A fix to avoid failing the linear mapping bootmem bounds check on
   NOMMU systems.

 - A fix for early alternatives on relocatable kernels.

* tag 'riscv-for-linus-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Fix RISCV_ALTERNATIVE_EARLY
  riscv: Do not restrict memory size because of linear mapping on nommu
  riscv: Fix toolchain vector detection
  riscv: misaligned: Restrict user access to kernel memory
  riscv: mm: Do not restrict mmap address based on hint
  riscv: selftests: Remove mmap hint address checks
  Revert "RISC-V: mm: Document mmap changes"

Author: torvalds

Documentation/arch/riscv/vm-layout.rst

@@ -134,19 +134,3 @@ RISC-V Linux Kernel SV57
    ffffffff00000000 |  -4     GB | ffffffff7fffffff |    2 GB | modules, BPF
    ffffffff80000000 |  -2     GB | ffffffffffffffff |    2 GB | kernel
   __________________|____________|__________________|_________|____________________________________________________________
-
-
-Userspace VAs
---------------------
-To maintain compatibility with software that relies on the VA space with a
-maximum of 48 bits the kernel will, by default, return virtual addresses to
-userspace from a 48-bit range (sv48). This default behavior is achieved by
-passing 0 into the hint address parameter of mmap. On CPUs with an address space
-smaller than sv48, the CPU maximum supported address space will be the default.
-
-Software can "opt-in" to receiving VAs from another VA space by providing
-a hint address to mmap. When a hint address is passed to mmap, the returned
-address will never use more bits than the hint address. For example, if a hint
-address of `1 << 40` is passed to mmap, a valid returned address will never use
-bits 41 through 63. If no mappable addresses are available in that range, mmap
-will return `MAP_FAILED`.

arch/riscv/Kconfig

@@ -552,8 +552,8 @@ config RISCV_ISA_SVPBMT
 config TOOLCHAIN_HAS_V
 	bool
 	default y
-	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
-	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
+	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
+	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
 	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
 	depends on AS_HAS_OPTION_ARCH
 

arch/riscv/include/asm/processor.h

@@ -14,36 +14,14 @@
 
 #include <asm/ptrace.h>
 
-/*
- * addr is a hint to the maximum userspace address that mmap should provide, so
- * this macro needs to return the largest address space available so that
- * mmap_end < addr, being mmap_end the top of that address space.
- * See Documentation/arch/riscv/vm-layout.rst for more details.
- */
 #define arch_get_mmap_end(addr, len, flags)			\
 ({								\
-	unsigned long mmap_end;					\
-	typeof(addr) _addr = (addr);				\
-	if ((_addr) == 0 || is_compat_task() ||			\
-	    ((_addr + len) > BIT(VA_BITS - 1)))			\
-		mmap_end = STACK_TOP_MAX;			\
-	else							\
-		mmap_end = (_addr + len);			\
-	mmap_end;						\
+	STACK_TOP_MAX;						\
 })
 
 #define arch_get_mmap_base(addr, base)				\
 ({								\
-	unsigned long mmap_base;				\
-	typeof(addr) _addr = (addr);				\
-	typeof(base) _base = (base);				\
-	unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);	\
-	if ((_addr) == 0 || is_compat_task() || 		\
-	    ((_addr + len) > BIT(VA_BITS - 1)))			\
-		mmap_base = (_base);				\
-	else							\
-		mmap_base = (_addr + len) - rnd_gap;		\
-	mmap_base;						\
+	base;							\
 })
 
 #ifdef CONFIG_64BIT

arch/riscv/include/asm/sbi.h

@@ -9,6 +9,7 @@
 
 #include <linux/types.h>
 #include <linux/cpumask.h>
+#include <linux/jump_label.h>
 
 #ifdef CONFIG_RISCV_SBI
 enum sbi_ext_id {
@@ -304,6 +305,7 @@ struct sbiret {
 };
 
 void sbi_init(void);
+long __sbi_base_ecall(int fid);
 struct sbiret __sbi_ecall(unsigned long arg0, unsigned long arg1,
 			  unsigned long arg2, unsigned long arg3,
 			  unsigned long arg4, unsigned long arg5,
@@ -373,7 +375,23 @@ static inline unsigned long sbi_mk_version(unsigned long major,
 		| (minor & SBI_SPEC_VERSION_MINOR_MASK);
 }
 
-int sbi_err_map_linux_errno(int err);
+static inline int sbi_err_map_linux_errno(int err)
+{
+	switch (err) {
+	case SBI_SUCCESS:
+		return 0;
+	case SBI_ERR_DENIED:
+		return -EPERM;
+	case SBI_ERR_INVALID_PARAM:
+		return -EINVAL;
+	case SBI_ERR_INVALID_ADDRESS:
+		return -EFAULT;
+	case SBI_ERR_NOT_SUPPORTED:
+	case SBI_ERR_FAILURE:
+	default:
+		return -ENOTSUPP;
+	};
+}
 
 extern bool sbi_debug_console_available;
 int sbi_debug_console_write(const char *bytes, unsigned int num_bytes);

arch/riscv/kernel/Makefile

@@ -20,17 +20,21 @@ endif
 ifdef CONFIG_RISCV_ALTERNATIVE_EARLY
 CFLAGS_alternative.o := -mcmodel=medany
 CFLAGS_cpufeature.o := -mcmodel=medany
+CFLAGS_sbi_ecall.o := -mcmodel=medany
 ifdef CONFIG_FTRACE
 CFLAGS_REMOVE_alternative.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_cpufeature.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_sbi_ecall.o = $(CC_FLAGS_FTRACE)
 endif
 ifdef CONFIG_RELOCATABLE
 CFLAGS_alternative.o += -fno-pie
 CFLAGS_cpufeature.o += -fno-pie
+CFLAGS_sbi_ecall.o += -fno-pie
 endif
 ifdef CONFIG_KASAN
 KASAN_SANITIZE_alternative.o := n
 KASAN_SANITIZE_cpufeature.o := n
+KASAN_SANITIZE_sbi_ecall.o := n
 endif
 endif
 
@@ -88,7 +92,7 @@ obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o
 
 obj-$(CONFIG_PERF_EVENTS)	+= perf_callchain.o
 obj-$(CONFIG_HAVE_PERF_REGS)	+= perf_regs.o
-obj-$(CONFIG_RISCV_SBI)		+= sbi.o
+obj-$(CONFIG_RISCV_SBI)		+= sbi.o sbi_ecall.o
 ifeq ($(CONFIG_RISCV_SBI), y)
 obj-$(CONFIG_SMP)		+= sbi-ipi.o
 obj-$(CONFIG_SMP) += cpu_ops_sbi.o

arch/riscv/kernel/sbi.c

@@ -14,9 +14,6 @@
 #include <asm/smp.h>
 #include <asm/tlbflush.h>
 
-#define CREATE_TRACE_POINTS
-#include <asm/trace.h>
-
 /* default SBI version is 0.1 */
 unsigned long sbi_spec_version __ro_after_init = SBI_SPEC_VERSION_DEFAULT;
 EXPORT_SYMBOL(sbi_spec_version);
@@ -27,55 +24,6 @@ static int (*__sbi_rfence)(int fid, const struct cpumask *cpu_mask,
 			   unsigned long start, unsigned long size,
 			   unsigned long arg4, unsigned long arg5) __ro_after_init;
 
-struct sbiret __sbi_ecall(unsigned long arg0, unsigned long arg1,
-			  unsigned long arg2, unsigned long arg3,
-			  unsigned long arg4, unsigned long arg5,
-			  int fid, int ext)
-{
-	struct sbiret ret;
-
-	trace_sbi_call(ext, fid);
-
-	register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
-	register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
-	register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
-	register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
-	register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
-	register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
-	register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
-	register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
-	asm volatile ("ecall"
-		      : "+r" (a0), "+r" (a1)
-		      : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
-		      : "memory");
-	ret.error = a0;
-	ret.value = a1;
-
-	trace_sbi_return(ext, ret.error, ret.value);
-
-	return ret;
-}
-EXPORT_SYMBOL(__sbi_ecall);
-
-int sbi_err_map_linux_errno(int err)
-{
-	switch (err) {
-	case SBI_SUCCESS:
-		return 0;
-	case SBI_ERR_DENIED:
-		return -EPERM;
-	case SBI_ERR_INVALID_PARAM:
-		return -EINVAL;
-	case SBI_ERR_INVALID_ADDRESS:
-		return -EFAULT;
-	case SBI_ERR_NOT_SUPPORTED:
-	case SBI_ERR_FAILURE:
-	default:
-		return -ENOTSUPP;
-	};
-}
-EXPORT_SYMBOL(sbi_err_map_linux_errno);
-
 #ifdef CONFIG_RISCV_SBI_V01
 static unsigned long __sbi_v01_cpumask_to_hartmask(const struct cpumask *cpu_mask)
 {
@@ -535,17 +483,6 @@ long sbi_probe_extension(int extid)
 }
 EXPORT_SYMBOL(sbi_probe_extension);
 
-static long __sbi_base_ecall(int fid)
-{
-	struct sbiret ret;
-
-	ret = sbi_ecall(SBI_EXT_BASE, fid, 0, 0, 0, 0, 0, 0);
-	if (!ret.error)
-		return ret.value;
-	else
-		return sbi_err_map_linux_errno(ret.error);
-}
-
 static inline long sbi_get_spec_version(void)
 {
 	return __sbi_base_ecall(SBI_EXT_BASE_GET_SPEC_VERSION);

arch/riscv/kernel/sbi_ecall.c

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Rivos Inc. */
+
+#include <asm/sbi.h>
+#define CREATE_TRACE_POINTS
+#include <asm/trace.h>
+
+long __sbi_base_ecall(int fid)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, fid, 0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		return ret.value;
+	else
+		return sbi_err_map_linux_errno(ret.error);
+}
+EXPORT_SYMBOL(__sbi_base_ecall);
+
+struct sbiret __sbi_ecall(unsigned long arg0, unsigned long arg1,
+			  unsigned long arg2, unsigned long arg3,
+			  unsigned long arg4, unsigned long arg5,
+			  int fid, int ext)
+{
+	struct sbiret ret;
+
+	trace_sbi_call(ext, fid);
+
+	register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
+	register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
+	register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
+	register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
+	register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
+	register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
+	register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
+	register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
+	asm volatile ("ecall"
+		       : "+r" (a0), "+r" (a1)
+		       : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
+		       : "memory");
+	ret.error = a0;
+	ret.value = a1;
+
+	trace_sbi_return(ext, ret.error, ret.value);
+
+	return ret;
+}
+EXPORT_SYMBOL(__sbi_ecall);

arch/riscv/kernel/traps_misaligned.c

@@ -417,7 +417,7 @@ int handle_misaligned_load(struct pt_regs *regs)
 
 	val.data_u64 = 0;
 	if (user_mode(regs)) {
-		if (raw_copy_from_user(&val, (u8 __user *)addr, len))
+		if (copy_from_user(&val, (u8 __user *)addr, len))
 			return -1;
 	} else {
 		memcpy(&val, (u8 *)addr, len);
@@ -515,7 +515,7 @@ int handle_misaligned_store(struct pt_regs *regs)
 		return -EOPNOTSUPP;
 
 	if (user_mode(regs)) {
-		if (raw_copy_to_user((u8 __user *)addr, &val, len))
+		if (copy_to_user((u8 __user *)addr, &val, len))
 			return -1;
 	} else {
 		memcpy((u8 *)addr, &val, len);

arch/riscv/mm/init.c

@@ -252,7 +252,7 @@ static void __init setup_bootmem(void)
 	 * The size of the linear page mapping may restrict the amount of
 	 * usable RAM.
 	 */
-	if (IS_ENABLED(CONFIG_64BIT)) {
+	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) {
 		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
 		memblock_cap_memory_range(phys_ram_base,
 					  max_mapped_addr - phys_ram_base);

tools/testing/selftests/riscv/mm/mmap_bottomup.c

@@ -7,8 +7,6 @@
 TEST(infinite_rlimit)
 {
 	EXPECT_EQ(BOTTOM_UP, memory_layout());
-
-	TEST_MMAPS;
 }
 
 TEST_HARNESS_MAIN