diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6221a1d057dd..accc400b43f1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3576,7 +3576,10 @@ emulation library even if a 387 maths coprocessor is present. - no5lvl [X86-64] Disable 5-level paging mode. Forces + no4lvl [RISCV] Disable 4-level and 5-level paging modes. Forces + kernel to use 3-level paging instead. + + no5lvl [X86-64,RISCV] Disable 5-level paging mode. Forces kernel to use 4-level paging instead. nofsgsbase [X86] Disables FSGSBASE instructions. diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index e859e1721a8f..d44d0fb98168 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -7,8 +7,9 @@ # OBJCOPYFLAGS := -O binary +LDFLAGS_vmlinux := -z norelro ifeq ($(CONFIG_RELOCATABLE),y) - LDFLAGS_vmlinux += -shared -Bsymbolic -z notext -z norelro --emit-relocs + LDFLAGS_vmlinux += -shared -Bsymbolic -z notext --emit-relocs KBUILD_CFLAGS += -fPIE endif ifeq ($(CONFIG_DYNAMIC_FTRACE),y) diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 392fa6e35d4a..0fee73a20c87 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -87,3 +87,5 @@ obj-$(CONFIG_EFI) += efi.o obj-$(CONFIG_COMPAT) += compat_syscall_table.o obj-$(CONFIG_COMPAT) += compat_signal.o obj-$(CONFIG_COMPAT) += compat_vdso/ + +obj-$(CONFIG_64BIT) += pi/ diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile new file mode 100644 index 000000000000..5d7cb991f2b8 --- /dev/null +++ b/arch/riscv/kernel/pi/Makefile @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: GPL-2.0 +# This file was copied from arm64/kernel/pi/Makefile. + +KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) -fpie \ + -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK_PLUGIN) \ + $(call cc-option,-mbranch-protection=none) \ + -I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \ + -D__DISABLE_EXPORTS -ffreestanding \ + -fno-asynchronous-unwind-tables -fno-unwind-tables \ + $(call cc-option,-fno-addrsig) + +KBUILD_CFLAGS += -mcmodel=medany + +CFLAGS_cmdline_early.o += -D__NO_FORTIFY +CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY + +GCOV_PROFILE := n +KASAN_SANITIZE := n +KCSAN_SANITIZE := n +UBSAN_SANITIZE := n +KCOV_INSTRUMENT := n + +$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \ + --remove-section=.note.gnu.property \ + --prefix-alloc-sections=.init +$(obj)/%.pi.o: $(obj)/%.o FORCE + $(call if_changed,objcopy) + +$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE + $(call if_changed_rule,cc_o_c) + +$(obj)/string.o: $(srctree)/lib/string.c FORCE + $(call if_changed_rule,cc_o_c) + +$(obj)/ctype.o: $(srctree)/lib/ctype.c FORCE + $(call if_changed_rule,cc_o_c) + +obj-y := cmdline_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o +extra-y := $(patsubst %.pi.o,%.o,$(obj-y)) diff --git a/arch/riscv/kernel/pi/cmdline_early.c b/arch/riscv/kernel/pi/cmdline_early.c new file mode 100644 index 000000000000..05652d13c746 --- /dev/null +++ b/arch/riscv/kernel/pi/cmdline_early.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include + +static char early_cmdline[COMMAND_LINE_SIZE]; + +/* + * Declare the functions that are exported (but prefixed) here so that LLVM + * does not complain it lacks the 'static' keyword (which, if added, makes + * LLVM complain because the function is actually unused in this file). + */ +u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa); + +static char *get_early_cmdline(uintptr_t dtb_pa) +{ + const char *fdt_cmdline = NULL; + unsigned int fdt_cmdline_size = 0; + int chosen_node; + + if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) { + chosen_node = fdt_path_offset((void *)dtb_pa, "/chosen"); + if (chosen_node >= 0) { + fdt_cmdline = fdt_getprop((void *)dtb_pa, chosen_node, + "bootargs", NULL); + if (fdt_cmdline) { + fdt_cmdline_size = strlen(fdt_cmdline); + strscpy(early_cmdline, fdt_cmdline, + COMMAND_LINE_SIZE); + } + } + } + + if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || + IS_ENABLED(CONFIG_CMDLINE_FORCE) || + fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) { + strncat(early_cmdline, CONFIG_CMDLINE, + COMMAND_LINE_SIZE - fdt_cmdline_size); + } + + return early_cmdline; +} + +static u64 match_noXlvl(char *cmdline) +{ + if (strstr(cmdline, "no4lvl")) + return SATP_MODE_48; + else if (strstr(cmdline, "no5lvl")) + return SATP_MODE_57; + + return 0; +} + +u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa) +{ + char *cmdline = get_early_cmdline(dtb_pa); + + return match_noXlvl(cmdline); +} diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index 615ff5842690..305877d85e96 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -83,6 +83,14 @@ SECTIONS /* Start of init data section */ __init_data_begin = .; INIT_DATA_SECTION(16) + + /* Those sections result from the compilation of kernel/pi/string.c */ + .init.pidata : { + *(.init.srodata.cst8*) + *(.init__bug_table*) + *(.init.sdata*) + } + .init.bss : { *(.init.bss) /* from the EFI stub */ } @@ -128,9 +136,10 @@ SECTIONS __rela_dyn_end = .; } + .got : { *(.got*) } + #ifdef CONFIG_RELOCATABLE .data.rel : { *(.data.rel*) } - .got : { *(.got*) } .plt : { *(.plt) } .dynamic : { *(.dynamic) } .dynsym : { *(.dynsym) } diff --git a/arch/riscv/lib/memcpy.S b/arch/riscv/lib/memcpy.S index 51ab716253fa..1a40d01a9543 100644 --- a/arch/riscv/lib/memcpy.S +++ b/arch/riscv/lib/memcpy.S @@ -106,3 +106,5 @@ WEAK(memcpy) 6: ret END(__memcpy) +SYM_FUNC_ALIAS(__pi_memcpy, __memcpy) +SYM_FUNC_ALIAS(__pi___memcpy, __memcpy) diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S index e0609e1f0864..838ff2022fe3 100644 --- a/arch/riscv/lib/memmove.S +++ b/arch/riscv/lib/memmove.S @@ -314,3 +314,5 @@ return_from_memmove: SYM_FUNC_END(memmove) SYM_FUNC_END(__memmove) +SYM_FUNC_ALIAS(__pi_memmove, __memmove) +SYM_FUNC_ALIAS(__pi___memmove, __memmove) diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S index db3d42d99b78..8ae3064e45ff 100644 --- a/arch/riscv/lib/strlen.S +++ b/arch/riscv/lib/strlen.S @@ -130,3 +130,4 @@ strlen_zbb: .option pop #endif SYM_FUNC_END(strlen) +SYM_FUNC_ALIAS(__pi_strlen, strlen) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index bce899b180cd..3ad771571c2d 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -746,6 +746,8 @@ static __init pgprot_t pgprot_from_va(uintptr_t va) #endif /* CONFIG_STRICT_KERNEL_RWX */ #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) +u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa); + static void __init disable_pgtable_l5(void) { pgtable_l5_enabled = false; @@ -760,17 +762,39 @@ static void __init disable_pgtable_l4(void) satp_mode = SATP_MODE_39; } +static int __init print_no4lvl(char *p) +{ + pr_info("Disabled 4-level and 5-level paging"); + return 0; +} +early_param("no4lvl", print_no4lvl); + +static int __init print_no5lvl(char *p) +{ + pr_info("Disabled 5-level paging"); + return 0; +} +early_param("no5lvl", print_no5lvl); + /* * There is a simple way to determine if 4-level is supported by the * underlying hardware: establish 1:1 mapping in 4-level page table mode * then read SATP to see if the configuration was taken into account * meaning sv48 is supported. */ -static __init void set_satp_mode(void) +static __init void set_satp_mode(uintptr_t dtb_pa) { u64 identity_satp, hw_satp; uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK; - bool check_l4 = false; + u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa); + + if (satp_mode_cmdline == SATP_MODE_57) { + disable_pgtable_l5(); + } else if (satp_mode_cmdline == SATP_MODE_48) { + disable_pgtable_l5(); + disable_pgtable_l4(); + return; + } create_p4d_mapping(early_p4d, set_satp_mode_pmd, (uintptr_t)early_pud, @@ -789,7 +813,8 @@ static __init void set_satp_mode(void) retry: create_pgd_mapping(early_pg_dir, set_satp_mode_pmd, - check_l4 ? (uintptr_t)early_pud : (uintptr_t)early_p4d, + pgtable_l5_enabled ? + (uintptr_t)early_p4d : (uintptr_t)early_pud, PGDIR_SIZE, PAGE_TABLE); identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode; @@ -800,9 +825,8 @@ retry: local_flush_tlb_all(); if (hw_satp != identity_satp) { - if (!check_l4) { + if (pgtable_l5_enabled) { disable_pgtable_l5(); - check_l4 = true; memset(early_pg_dir, 0, PAGE_SIZE); goto retry; } @@ -1031,7 +1055,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #endif #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) - set_satp_mode(); + set_satp_mode(dtb_pa); #endif /*