Currently, the compat32 passes PT_* request values to kernel functions
without translation. This works fine for low PT_* requests that happen
to have the same values both on i386 and amd64. However, for requests
higher than PT_SETFPREGS, the value passed from userland (matching i386
const) does not match the correct kernel (amd64) request. As a result,
e.g. when compat32 process calls PT_GETDBREGS, kernel actually processes
it as PT_SETSTEP.
To resolve this, introduce support for compat32 PT_* request
translation. The interface is based on PTRACE_TRANSLATE_REQUEST32 macro
that is defined to a mapping function on architectures needing it.
In case of amd64, this function maps userland i386 PT_* values into
appropriate amd64 PT_* values.
For the time being, the two additional PT_GETXMMREGS and PT_SETXMMREGS
requests are unsupported due to lack of matching free amd64 constant.
---
sys/arch/amd64/amd64/netbsd32_machdep.c | 37 +++++++++++++++++++++++
sys/arch/amd64/include/netbsd32_machdep.h | 3 ++
sys/arch/amd64/include/ptrace.h | 2 ++
sys/compat/netbsd32/netbsd32_ptrace.c | 8 ++++-
sys/sys/ptrace.h | 4 +++
5 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/sys/arch/amd64/amd64/netbsd32_machdep.c
b/sys/arch/amd64/amd64/netbsd32_machdep.c
index 39d671a4b9b6..06f6cbdf3703 100644
--- a/sys/arch/amd64/amd64/netbsd32_machdep.c
+++ b/sys/arch/amd64/amd64/netbsd32_machdep.c
@@ -335,6 +335,43 @@ cpu_coredump32(struct lwp *l, struct coredump_iostate
*iocookie,
}
#endif
+int
+netbsd32_ptrace_translate_request(int req)
+{
+
+ switch (req)
+ {
+ case 0 ... PT_FIRSTMACH - 1:
+ return req;
+ case PT_FIRSTMACH + 0:
+ return PT_STEP;
+ case PT_FIRSTMACH + 1:
+ return PT_GETREGS;
+ case PT_FIRSTMACH + 2:
+ return PT_SETREGS;
+ case PT_FIRSTMACH + 3:
+ return PT_GETFPREGS;
+ case PT_FIRSTMACH + 4:
+ return PT_SETFPREGS;
+ case PT_FIRSTMACH + 5:
+ /* PT_GETXMMREGS */
+ return -1;
+ case PT_FIRSTMACH + 6:
+ /* PT_SETXMMREGS */
+ return -1;
+ case PT_FIRSTMACH + 7:
+ return PT_GETDBREGS;
+ case PT_FIRSTMACH + 8:
+ return PT_SETDBREGS;
+ case PT_FIRSTMACH + 9:
+ return PT_SETSTEP;
+ case PT_FIRSTMACH + 10:
+ return PT_CLEARSTEP;
+ default:
+ return -1;
+ }
+}
+
int
netbsd32_process_read_regs(struct lwp *l, struct reg32 *regs)
{
diff --git a/sys/arch/amd64/include/netbsd32_machdep.h
b/sys/arch/amd64/include/netbsd32_machdep.h
index 51691eb7c90f..37019d29134d 100644
--- a/sys/arch/amd64/include/netbsd32_machdep.h
+++ b/sys/arch/amd64/include/netbsd32_machdep.h
@@ -151,6 +151,9 @@ struct x86_64_set_mtrr_args32 {
#define NETBSD32_MID_MACHINE MID_I386
+/* Translate ptrace() PT_* request from 32-bit userland to kernel. */
+int netbsd32_ptrace_translate_request(int);
+
int netbsd32_process_read_regs(struct lwp *, struct reg32 *);
int netbsd32_process_read_fpregs(struct lwp *, struct fpreg32 *, size_t *);
int netbsd32_process_read_dbregs(struct lwp *, struct dbreg32 *, size_t *);
diff --git a/sys/arch/amd64/include/ptrace.h b/sys/arch/amd64/include/ptrace.h
index c5cef941fd16..8d0f54dbad24 100644
--- a/sys/arch/amd64/include/ptrace.h
+++ b/sys/arch/amd64/include/ptrace.h
@@ -87,6 +87,8 @@
#define process_reg32 struct reg32
#define process_fpreg32 struct fpreg32
#define process_dbreg32 struct dbreg32
+
+#define PTRACE_TRANSLATE_REQUEST32(x) netbsd32_ptrace_translate_request(x)
#endif /* COMPAT_NETBSD32 */
#endif /* _KERNEL_OPT */
diff --git a/sys/compat/netbsd32/netbsd32_ptrace.c
b/sys/compat/netbsd32/netbsd32_ptrace.c
index 614d363c3126..feb2b99c8d54 100644
--- a/sys/compat/netbsd32/netbsd32_ptrace.c
+++ b/sys/compat/netbsd32/netbsd32_ptrace.c
@@ -243,6 +243,8 @@ int
netbsd32_ptrace(struct lwp *l, const struct netbsd32_ptrace_args *uap,
register_t *retval)
{
+ int req;
+
/* {
syscallarg(int) req;
syscallarg(pid_t) pid;
@@ -250,7 +252,11 @@ netbsd32_ptrace(struct lwp *l, const struct
netbsd32_ptrace_args *uap,
syscallarg(int) data;
} */
- return do_ptrace(&netbsd32_ptm, l, SCARG(uap, req), SCARG(uap, pid),
+ req = PTRACE_TRANSLATE_REQUEST32(SCARG(uap, req));
+ if (req == -1)
+ return EOPNOTSUPP;
+
+ return do_ptrace(&netbsd32_ptm, l, req, SCARG(uap, pid),
SCARG_P32(uap, addr), SCARG(uap, data), retval);
}
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
index b213b38f5c6b..484f0ff6d268 100644
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -283,6 +283,10 @@ int ptrace_machdep_dorequest(struct lwp *, struct
lwp *, int,
#define FIX_SSTEP(p)
#endif
+#ifndef PTRACE_TRANSLATE_REQUEST32
+#define PTRACE_TRANSLATE_REQUEST32(x) x
+#endif
+
#else /* !_KERNEL */
#include <sys/cdefs.h>
--
2.22.0.rc1
