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>
This commit is contained in:
Guo Ren 2022-04-05 15:13:13 +08:00 committed by Palmer Dabbelt
parent 7383ee0531
commit 4608c15959
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889

View File

@ -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;
}