Added suport for Riscv64 architecture

Makefile

@@ -82,6 +82,8 @@ ifndef ARCH
         ARCH = arm
     else ifeq ($(findstring aarch64, $(GCC_TARGET)), aarch64)
         ARCH = arm64
+    else ifeq ($(findstring riscv64, $(GCC_TARGET)), riscv64)
+        ARCH = riscv64
     else
         $(error unable to detect arch: $(GCC_TARGET))
     endif
@@ -94,6 +96,8 @@ else ifeq ($(ARCH), arm)
     PCFLAGS += -marm
 else ifeq ($(ARCH), arm64)
     # do nothing
+else ifeq ($(ARCH), riscv64)
+    # do nothing
 else
     $(error unsupported arch: $(ARCH))
 endif

README.md

@@ -33,7 +33,7 @@ make COMPRESS_LZ4=1 CHECKSUM_MD5=1 ENCRYPT=1
 ```
 
 ##### cross compilation
-Currently, supported architectures are x86_64, arm and arm64. You can cross compile memcr by providing `CROSS_COMPILE` prefix. i.e.:
+Currently, supported architectures are x86_64, arm,  arm64 and riscv64. You can cross compile memcr by providing `CROSS_COMPILE` prefix. i.e.:
 ```
 make CROSS_COMPILE=arm-linux-gnueabihf-
 make CROSS_COMPILE=aarch64-linux-gnu-

arch/cpu.h

@@ -25,6 +25,8 @@
 #include "arm/cpu.h"
 #elif defined(__aarch64__)
 #include "arm64/cpu.h"
+#elif defined(__riscv_xlen)
+#include "riscv64/cpu.h"
 #else
 #error unsupported arch
 #endif

arch/riscv64/cpu.c

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2023 Mariusz Kozłowski
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2
+ * of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <linux/ptrace.h>
+#include <sys/user.h>
+#include <assert.h>
+
+#include "../cpu.h"
+
+void set_cpu_regs(struct registers *regs, unsigned long *pc, unsigned long arg0, unsigned long arg1)
+{
+	regs->pc = (unsigned long)pc;		/* point to the injected blob */
+	regs->s6 = arg0;			/* s6 used as arg0 to blob */
+	regs->s7 = arg1;			/* s7 used as arg1 to blob */
+}
+
+void *get_cpu_regs_sp(struct registers *regs)
+{
+	return (void *)regs->sp;
+}
+
+void *get_cpu_regs_pc(struct registers *regs)
+{
+	return (void *)regs->pc;
+}
+
+unsigned long get_cpu_syscall_ret(struct registers *regs)
+{
+	return regs->a0;
+}
+
+#if 0
+unsigned long get_cpu_syscall_arg0(struct registers *regs)
+{
+	return regs->x10;
+}
+#endif
+
+void print_cpu_regs(struct registers *regs)
+{
+	int idx;
+	const char *rg_names[] = {
+		"pc", "ra", "sp", "gp", "tp", "t0", "t1", "t2",
+		"s0", "s1", "a0", "a1", "a2", "a3", "a4", "a5",
+		"a6", "a7", "s2", "s3", "s4", "s5", "s6", "s7",
+		"s8", "s9", "s10", "s11", "t3", "t4", "t5", "t6"
+	};
+
+	for (idx = 0; idx < sizeof(*regs)/sizeof(regs->pc); idx++) {
+		fprintf(stdout, "regs[%s]\t %0*lx\n", rg_names[idx], 2 * (int)sizeof(unsigned long), ((unsigned long *)regs)[idx]);
+	}
+}
+
+static_assert(sizeof(struct registers) == sizeof(struct user_regs_struct), "struct registers size mismatch");

arch/riscv64/cpu.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2023 Mariusz Kozłowski
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2
+ * of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+struct registers {
+	unsigned long pc;
+	unsigned long ra;
+	unsigned long sp;
+	unsigned long gp;
+	unsigned long tp;
+	unsigned long t0;
+	unsigned long t1;
+	unsigned long t2;
+	unsigned long s0;
+	unsigned long s1;
+	unsigned long a0;
+	unsigned long a1;
+	unsigned long a2;
+	unsigned long a3;
+	unsigned long a4;
+	unsigned long a5;
+	unsigned long a6;
+	unsigned long a7;
+	unsigned long s2;
+	unsigned long s3;
+	unsigned long s4;
+	unsigned long s5;
+	unsigned long s6;
+	unsigned long s7;
+	unsigned long s8;
+	unsigned long s9;
+	unsigned long s10;
+	unsigned long s11;
+	unsigned long t3;
+	unsigned long t4;
+	unsigned long t5;
+	unsigned long t6;
+};

arch/riscv64/enter.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2023 Mariusz Kozłowski
+ * Copyright (C) 2024 Wojciech Łazarski
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2
+ * of the license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <signal.h>
+#include <sys/mman.h>
+#include <linux/sched.h>
+
+#include <string.h>
+
+
+static void __attribute__((used)) container(void)
+{
+	/*
+	 * Upon completion, each blob triggers debug trap to pass the
+	 * control back to the main program.
+	 */
+
+	/* rt_sigprocmask(), expects pointer to area for masks in a6 */
+
+	asm volatile(
+		".global sigprocmask_blob			\n"
+		".align 3					\n"
+		"sigprocmask_blob:				\n"
+		"li a7, 135					\n" /* __NR_rt_sigprocmask */
+		"li a0, %0					\n" /* @how */
+		"mv a1, s6					\n" /* @nset */
+		"mv a2, s6					\n" /* @oset */
+		"li a3, 8					\n" /* @sigsetsize */
+		"ecall						\n"
+		"ebreak						\n" /* SIGTRAP */
+		".global sigprocmask_blob_size			\n"
+		".align 3					\n"
+		"sigprocmask_blob_size:				\n"
+		".int sigprocmask_blob_size - sigprocmask_blob	\n"
+		:: "i" (SIG_SETMASK)
+	);
+
+	/* mmaps anon area for parasite_blob */
+	asm volatile(
+		".global mmap_blob				\n"
+		".align 3					\n"
+		"mmap_blob:					\n"
+		"li a7, 222					\n" /* __NR_mmap2 */
+		"li a0, 0					\n" /* @addr */
+		"mv a1, s6					\n" /* @len */
+		"li a2, %0					\n" /* @prot */
+		"li a3, %1					\n" /* @flags */
+		"li a4, -1					\n" /* @fd */
+		"li a5, 0					\n" /* @off */
+		"ecall						\n"
+		"ebreak						\n" /* SIGTRAP */
+		".global mmap_blob_size				\n"
+
+		".align 3					\n"
+		"mmap_blob_size:				\n"
+		".int mmap_blob_size - mmap_blob		\n"
+		:: "i" (PROT_EXEC | PROT_READ | PROT_WRITE),
+		   "i" (MAP_ANONYMOUS | MAP_PRIVATE)
+	);
+
+	/* clones parasite, expects parasite address in a6 */
+	asm volatile(
+		".global clone_blob				\n"
+		".align 3					\n"
+		"clone_blob:					\n"
+		"li a7, 220					\n" /* __NR_clone */
+		"ld a0, CLONE_FLAGS				\n" /* @flags */
+		"li a1, 0					\n" /* @newsp */
+		"li a2, 0					\n" /* @parent_tid */
+		"li a3, 0					\n" /* @child_tid */
+		"ecall						\n"
+		"li a1, 0					\n"
+		"beq a0, a1, .child				\n"
+		"ebreak						\n" /* SIGTRAP */
+		".child:					\n"
+		"jr s6						\n" /* br parasite */
+		"CLONE_FLAGS:					\n"
+		".quad (%0 & 0xffffffff)			\n" /* zero high .word */
+		".global clone_blob_size			\n"
+		"clone_blob_size:				\n"
+
+		".align 3					\n"
+		".int clone_blob_size - clone_blob		\n"
+		:: "i" (CLONE_FILES | CLONE_FS | CLONE_IO | CLONE_SIGHAND | CLONE_SYSVSEM | CLONE_THREAD | CLONE_VM)
+	);
+
+	/* munmap anon area for parasite_blob, expects addr in a6 and len in a7 */
+	asm volatile(
+		".global munmap_blob				\n"
+		".align 3					\n"
+		"munmap_blob:					\n"
+		"li a7, 215					\n" /* __NR_munmap */
+		"mv a0, s6					\n" /* @addr */
+		"mv a1, s7					\n" /* @len */
+		"ecall						\n"
+		"ebreak						\n" /* SIGTRAP */
+		".global munmap_blob_size			\n"
+
+		".align 3					\n"
+		"munmap_blob_size:				\n"
+		".int munmap_blob_size - munmap_blob		\n"
+	);
+}