Resguardo inicial

linux-7.2.3/arch/riscv/kernel/pi/Makefile

@@ -0,0 +1,42 @@
+# 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_KSTACK_ERASE) \
+		   $(call cc-option,-mbranch-protection=none) \
+		   -I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
+		   -include $(srctree)/include/linux/hidden.h \
+		   -D__DISABLE_EXPORTS -ffreestanding \
+		   -fno-asynchronous-unwind-tables -fno-unwind-tables \
+		   $(call cc-option,-fno-addrsig)
+
+# Disable LTO
+KBUILD_CFLAGS	:= $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS))
+
+KBUILD_CFLAGS	+= -mcmodel=medany
+
+CFLAGS_cmdline_early.o += -D__NO_FORTIFY
+CFLAGS_fdt_early.o += -D__NO_FORTIFY
+# lib/string.c already defines __NO_FORTIFY
+CFLAGS_ctype.o += -D__NO_FORTIFY
+CFLAGS_lib-fdt.o += -D__NO_FORTIFY
+CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY
+CFLAGS_archrandom_early.o += -D__NO_FORTIFY
+
+$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \
+			       --remove-section=.note.gnu.property \
+			       --prefix-alloc-sections=.init.pi
+$(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 fdt_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o archrandom_early.pi.o
+targets		:= $(patsubst %.pi.o,%.o,$(obj-y))

linux-7.2.3/arch/riscv/kernel/pi/archrandom_early.c

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/csr.h>
+#include <linux/processor.h>
+
+#include "pi.h"
+
+/*
+ * To avoid rewriting code include asm/archrandom.h and create macros
+ * for the functions that won't be included.
+ */
+#undef riscv_has_extension_unlikely
+#define riscv_has_extension_likely(...) false
+#undef pr_err_once
+#define pr_err_once(...)
+
+#include <asm/archrandom.h>
+
+u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa)
+{
+	unsigned long seed = 0;
+
+	if (!fdt_early_match_extension_isa((const void *)dtb_pa, "zkr"))
+		return 0;
+
+	if (!csr_seed_long(&seed))
+		return 0;
+
+	return seed;
+}

linux-7.2.3/arch/riscv/kernel/pi/cmdline_early.c

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/libfdt.h>
+#include <linux/string.h>
+#include <asm/pgtable.h>
+#include <asm/setup.h>
+
+#include "pi.h"
+
+static char early_cmdline[COMMAND_LINE_SIZE];
+
+static char *get_early_cmdline(uintptr_t dtb_pa)
+{
+	const char *fdt_cmdline;
+	ssize_t 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 = strscpy(early_cmdline, fdt_cmdline);
+				if (fdt_cmdline_size < 0)
+					return early_cmdline;
+			}
+		}
+	}
+
+	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+	    fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */)
+		strscpy(early_cmdline + fdt_cmdline_size, CONFIG_CMDLINE,
+			COMMAND_LINE_SIZE - fdt_cmdline_size);
+
+	return early_cmdline;
+}
+
+static u64 match_noXlvl(char *cmdline)
+{
+	if (strstr(cmdline, "no4lvl"))
+		return SATP_MODE_39;
+	else if (strstr(cmdline, "no5lvl"))
+		return SATP_MODE_48;
+
+	return 0;
+}
+
+u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa)
+{
+	char *cmdline = get_early_cmdline(dtb_pa);
+
+	return match_noXlvl(cmdline);
+}
+
+static bool match_nokaslr(char *cmdline)
+{
+	return strstr(cmdline, "nokaslr");
+}
+
+bool set_nokaslr_from_cmdline(uintptr_t dtb_pa)
+{
+	char *cmdline = get_early_cmdline(dtb_pa);
+
+	return match_nokaslr(cmdline);
+}

linux-7.2.3/arch/riscv/kernel/pi/fdt_early.c

@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/libfdt.h>
+#include <linux/ctype.h>
+#include <asm/csr.h>
+
+#include "pi.h"
+
+u64 get_kaslr_seed(uintptr_t dtb_pa)
+{
+	int node, len;
+	fdt64_t *prop;
+	u64 ret;
+
+	node = fdt_path_offset((void *)dtb_pa, "/chosen");
+	if (node < 0)
+		return 0;
+
+	prop = fdt_getprop_w((void *)dtb_pa, node, "kaslr-seed", &len);
+	if (!prop || len != sizeof(u64))
+		return 0;
+
+	ret = fdt64_to_cpu(*prop);
+	*prop = 0;
+	return ret;
+}
+
+/**
+ *  fdt_device_is_available - check if a device is available for use
+ *
+ * @fdt: pointer to the device tree blob
+ * @node: offset of the node whose property to find
+ *
+ *  Returns true if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+static bool fdt_device_is_available(const void *fdt, int node)
+{
+	const char *status;
+	int statlen;
+
+	status = fdt_getprop(fdt, node, "status", &statlen);
+	if (!status)
+		return true;
+
+	if (statlen > 0) {
+		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+			return true;
+	}
+
+	return false;
+}
+
+/* Copy of fdt_nodename_eq_ */
+static int fdt_node_name_eq(const void *fdt, int offset,
+			    const char *s)
+{
+	int olen;
+	int len = strlen(s);
+	const char *p = fdt_get_name(fdt, offset, &olen);
+
+	if (!p || olen < len)
+		/* short match */
+		return 0;
+
+	if (memcmp(p, s, len) != 0)
+		return 0;
+
+	if (p[len] == '\0')
+		return 1;
+	else if (!memchr(s, '@', len) && (p[len] == '@'))
+		return 1;
+	else
+		return 0;
+}
+
+/**
+ *  isa_string_contains - check if isa string contains an extension
+ *
+ * @isa_str: isa string to search
+ * @ext_name: the extension to search for
+ *
+ *  Returns true if the extension is in the given isa string,
+ *  false otherwise
+ */
+static bool isa_string_contains(const char *isa_str, const char *ext_name)
+{
+	size_t i, single_end, len = strlen(ext_name);
+	char ext_end;
+
+	/* Error must contain rv32/64 */
+	if (strlen(isa_str) < 4)
+		return false;
+
+	if (len == 1) {
+		single_end = strcspn(isa_str, "sSxXzZ");
+		/* Search for single chars between rv32/64 and multi-letter extensions */
+		for (i = 4; i < single_end; i++) {
+			if (tolower(isa_str[i]) == ext_name[0])
+				return true;
+		}
+		return false;
+	}
+
+	/* Skip to start of multi-letter extensions */
+	isa_str = strpbrk(isa_str, "sSxXzZ");
+	while (isa_str) {
+		if (strncasecmp(isa_str, ext_name, len) == 0) {
+			ext_end = isa_str[len];
+			/* Check if matches the whole extension. */
+			if (ext_end == '\0' || ext_end == '_')
+				return true;
+		}
+		/* Multi-letter extensions must be split from other multi-letter
+		 * extensions with an "_", the end of a multi-letter extension will
+		 * either be the null character or the "_" at the start of the next
+		 * multi-letter extension.
+		 */
+		isa_str = strchr(isa_str, '_');
+		if (isa_str)
+			isa_str++;
+	}
+
+	return false;
+}
+
+/**
+ *  early_cpu_isa_ext_available - check if cpu node has an extension
+ *
+ * @fdt: pointer to the device tree blob
+ * @node: offset of the cpu node
+ * @ext_name: the extension to search for
+ *
+ *  Returns true if the cpu node has the extension,
+ *  false otherwise
+ */
+static bool early_cpu_isa_ext_available(const void *fdt, int node, const char *ext_name)
+{
+	const void *prop;
+	int len;
+
+	prop = fdt_getprop(fdt, node, "riscv,isa-extensions", &len);
+	if (prop && fdt_stringlist_contains(prop, len, ext_name))
+		return true;
+
+	prop = fdt_getprop(fdt, node, "riscv,isa", &len);
+	if (prop && isa_string_contains(prop, ext_name))
+		return true;
+
+	return false;
+}
+
+/**
+ *  fdt_early_match_extension_isa - check if all cpu nodes have an extension
+ *
+ * @fdt: pointer to the device tree blob
+ * @ext_name: the extension to search for
+ *
+ *  Returns true if the all available the cpu nodes have the extension,
+ *  false otherwise
+ */
+bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name)
+{
+	int node, parent;
+	bool ret = false;
+
+	parent = fdt_path_offset(fdt, "/cpus");
+	if (parent < 0)
+		return false;
+
+	fdt_for_each_subnode(node, fdt, parent) {
+		if (!fdt_node_name_eq(fdt, node, "cpu"))
+			continue;
+
+		if (!fdt_device_is_available(fdt, node))
+			continue;
+
+		if (!early_cpu_isa_ext_available(fdt, node, ext_name))
+			return false;
+
+		ret = true;
+	}
+
+	return ret;
+}
+
+/**
+ *  set_satp_mode_from_fdt - determine SATP mode based on the MMU type in fdt
+ *
+ * @dtb_pa: physical address of the device tree blob
+ *
+ *  Returns the SATP mode corresponding to the MMU type of the first enabled CPU,
+ *  0 otherwise
+ */
+u64 set_satp_mode_from_fdt(uintptr_t dtb_pa)
+{
+	const void *fdt = (const void *)dtb_pa;
+	const char *mmu_type;
+	int node, parent;
+
+	parent = fdt_path_offset(fdt, "/cpus");
+	if (parent < 0)
+		return 0;
+
+	fdt_for_each_subnode(node, fdt, parent) {
+		if (!fdt_node_name_eq(fdt, node, "cpu"))
+			continue;
+
+		if (!fdt_device_is_available(fdt, node))
+			continue;
+
+		mmu_type = fdt_getprop(fdt, node, "mmu-type", NULL);
+		if (!mmu_type)
+			break;
+
+		if (!strcmp(mmu_type, "riscv,sv39"))
+			return SATP_MODE_39;
+		else if (!strcmp(mmu_type, "riscv,sv48"))
+			return SATP_MODE_48;
+		break;
+	}
+
+	return 0;
+}

linux-7.2.3/arch/riscv/kernel/pi/pi.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _RISCV_PI_H_
+#define _RISCV_PI_H_
+
+#include <linux/types.h>
+
+/*
+ * The following functions are exported (but prefixed). Declare them here so
+ * that LLVM does not complain it lacks the 'static' keyword (which, if
+ * added, makes LLVM complain because the function is unused).
+ */
+
+u64 get_kaslr_seed(uintptr_t dtb_pa);
+u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa);
+bool set_nokaslr_from_cmdline(uintptr_t dtb_pa);
+u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa);
+u64 set_satp_mode_from_fdt(uintptr_t dtb_pa);
+
+bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name);
+
+#endif /* _RISCV_PI_H_ */