riscv: compat: ptrace: Add compat_arch_ptrace implement

Now, you can use native gdb on riscv64 for rv32 app debugging. $ uname -a Linux buildroot 5.16.0-rc4-00036-gbef6b82fdf23-dirty #53 SMP Mon Dec 20 23:06:53 CST 2021 riscv64 GNU/Linux $ cat /proc/cpuinfo processor : 0 hart : 0 isa : rv64imafdcsuh mmu : sv48 $ file /bin/busybox /bin/busybox: setuid ELF 32-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped $ file /usr/bin/gdb /usr/bin/gdb: ELF 32-bit LSB shared object, UCB RISC-V, version 1 (GNU/Linux), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped $ /usr/bin/gdb /bin/busybox GNU gdb (GDB) 10.2 Copyright (C) 2021 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> ... Reading symbols from /bin/busybox... (No debugging symbols found in /bin/busybox) (gdb) b main Breakpoint 1 at 0x8ddc (gdb) r Starting program: /bin/busybox Failed to read a valid object file image from memory. Breakpoint 1, 0x555a8ddc in main () (gdb) i r ra 0x77df0b74 0x77df0b74 sp 0x7fdd3d10 0x7fdd3d10 gp 0x5567e800 0x5567e800 <bb_common_bufsiz1+160> tp 0x77f64280 0x77f64280 t0 0x0 0 t1 0x555a6fac 1431990188 t2 0x77dd8db4 2011008436 fp 0x7fdd3e34 0x7fdd3e34 s1 0x7fdd3e34 2145205812 a0 0xffffffff -1 a1 0x2000 8192 a2 0x7fdd3e3c 2145205820 a3 0x0 0 a4 0x7fdd3d30 2145205552 a5 0x555a8dc0 1431997888 a6 0x77f2c170 2012397936 a7 0x6a7c7a2f 1786542639 s2 0x0 0 s3 0x0 0 s4 0x555a8dc0 1431997888 s5 0x77f8a3a8 2012783528 s6 0x7fdd3e3c 2145205820 s7 0x5567cecc 1432866508 --Type <RET> for more, q to quit, c to continue without paging-- s8 0x1 1 s9 0x0 0 s10 0x55634448 1432568904 s11 0x0 0 t3 0x77df0bb8 2011106232 t4 0x42fc 17148 t5 0x0 0 t6 0x40 64 pc 0x555a8ddc 0x555a8ddc <main+28> (gdb) si 0x555a78f0 in mallopt@plt () (gdb) c Continuing. BusyBox v1.34.1 (2021-12-19 22:39:48 CST) multi-call binary. BusyBox is copyrighted by many authors between 1998-2015. Licensed under GPLv2. See source distribution for detailed copyright notices. Usage: busybox [function [arguments]...] or: busybox --list[-full] ... [Inferior 1 (process 107) exited normally] (gdb) q Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20220405071314.3225832-20-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-24 12:44:11 +08:00 · 2022-04-05 15:13:13 +08:00 · 2022-04-05 15:13:13 +08:00 · 4608c15959
commit 4608c15959
parent 7383ee0531
1 changed files with 82 additions and 5 deletions
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@ -12,6 +12,7 @@
 #include <asm/thread_info.h>
 #include <asm/switch_to.h>
 #include <linux/audit.h>
+#include <linux/compat.h>
 #include <linux/ptrace.h>
 #include <linux/elf.h>
 #include <linux/regset.h>
@ -110,11 +111,6 @@ static const struct user_regset_view riscv_user_native_view = {
 	.n = ARRAY_SIZE(riscv_user_regset),
 };

-const struct user_regset_view *task_user_regset_view(struct task_struct *task)
-{
-	return &riscv_user_native_view;
-}
-
 struct pt_regs_offset {
 	const char *name;
 	int offset;
@ -272,3 +268,84 @@ __visible void do_syscall_trace_exit(struct pt_regs *regs)
 		trace_sys_exit(regs, regs_return_value(regs));
 #endif
 }
+
+#ifdef CONFIG_COMPAT
+static int compat_riscv_gpr_get(struct task_struct *target,
+				const struct user_regset *regset,
+				struct membuf to)
+{
+	struct compat_user_regs_struct cregs;
+
+	regs_to_cregs(&cregs, task_pt_regs(target));
+
+	return membuf_write(&to, &cregs,
+			    sizeof(struct compat_user_regs_struct));
+}
+
+static int compat_riscv_gpr_set(struct task_struct *target,
+				const struct user_regset *regset,
+				unsigned int pos, unsigned int count,
+				const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct compat_user_regs_struct cregs;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &cregs, 0, -1);
+
+	cregs_to_regs(&cregs, task_pt_regs(target));
+
+	return ret;
+}
+
+static const struct user_regset compat_riscv_user_regset[] = {
+	[REGSET_X] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(compat_elf_greg_t),
+		.align = sizeof(compat_elf_greg_t),
+		.regset_get = compat_riscv_gpr_get,
+		.set = compat_riscv_gpr_set,
+	},
+#ifdef CONFIG_FPU
+	[REGSET_F] = {
+		.core_note_type = NT_PRFPREG,
+		.n = ELF_NFPREG,
+		.size = sizeof(elf_fpreg_t),
+		.align = sizeof(elf_fpreg_t),
+		.regset_get = riscv_fpr_get,
+		.set = riscv_fpr_set,
+	},
+#endif
+};
+
+static const struct user_regset_view compat_riscv_user_native_view = {
+	.name = "riscv",
+	.e_machine = EM_RISCV,
+	.regsets = compat_riscv_user_regset,
+	.n = ARRAY_SIZE(compat_riscv_user_regset),
+};
+
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+			compat_ulong_t caddr, compat_ulong_t cdata)
+{
+	long ret = -EIO;
+
+	switch (request) {
+	default:
+		ret = compat_ptrace_request(child, request, caddr, cdata);
+		break;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_COMPAT */
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+#ifdef CONFIG_COMPAT
+	if (test_tsk_thread_flag(task, TIF_32BIT))
+		return &compat_riscv_user_native_view;
+	else
+#endif
+		return &riscv_user_native_view;
+}