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authorJohn Baldwin <jhb@FreeBSD.org>2015-09-01 22:24:54 +0000
committerJohn Baldwin <jhb@FreeBSD.org>2015-09-01 22:24:54 +0000
commit183b68f74f05cf7d66ab344857cd25e4c00513b2 (patch)
tree7d48ab783270ef6dbf8fe7948572ad12b96d274c
parent45d4c036ec4a6dc57b6666d49cd6a2f48976c7a5 (diff)
downloadsrc-183b68f74f05cf7d66ab344857cd25e4c00513b2.tar.gz
src-183b68f74f05cf7d66ab344857cd25e4c00513b2.zip
Export current system call code and argument count for system call entry
and exit events. procfs stop events for system call tracing report these values (argument count for system call entry and code for system call exit), but ptrace() does not provide this information. (Note that while the system call code can be determined in an ABI-specific manner during system call entry, it is not generally available during system call exit.) The values are exported via new fields at the end of struct ptrace_lwpinfo available via PT_LWPINFO. Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D3536
Notes
Notes: svn path=/head/; revision=287386
-rw-r--r--sys/kern/subr_syscall.c6
-rw-r--r--sys/kern/sys_process.c11
-rw-r--r--sys/sys/proc.h4
-rw-r--r--sys/sys/ptrace.h2
4 files changed, 22 insertions, 1 deletions
diff --git a/sys/kern/subr_syscall.c b/sys/kern/subr_syscall.c
index 070ba281cbaf..292b942d4d94 100644
--- a/sys/kern/subr_syscall.c
+++ b/sys/kern/subr_syscall.c
@@ -85,6 +85,8 @@ syscallenter(struct thread *td, struct syscall_args *sa)
STOPEVENT(p, S_SCE, sa->narg);
if (p->p_flag & P_TRACED && p->p_stops & S_PT_SCE) {
PROC_LOCK(p);
+ td->td_dbg_sc_code = sa->code;
+ td->td_dbg_sc_narg = sa->narg;
ptracestop((td), SIGTRAP);
PROC_UNLOCK(p);
}
@@ -94,6 +96,10 @@ syscallenter(struct thread *td, struct syscall_args *sa)
* debugger modified registers or memory.
*/
error = (p->p_sysent->sv_fetch_syscall_args)(td, sa);
+ PROC_LOCK(p);
+ td->td_dbg_sc_code = sa->code;
+ td->td_dbg_sc_narg = sa->narg;
+ PROC_UNLOCK(p);
#ifdef KTRACE
if (KTRPOINT(td, KTR_SYSCALL))
ktrsyscall(sa->code, sa->narg, sa->args);
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 66109604ad57..eb50acda099d 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -97,6 +97,8 @@ struct ptrace_lwpinfo32 {
struct siginfo32 pl_siginfo; /* siginfo for signal */
char pl_tdname[MAXCOMLEN + 1]; /* LWP name. */
int pl_child_pid; /* New child pid */
+ u_int pl_syscall_code;
+ u_int pl_syscall_narg;
};
#endif
@@ -481,6 +483,8 @@ ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
strcpy(pl32->pl_tdname, pl->pl_tdname);
pl32->pl_child_pid = pl->pl_child_pid;
+ pl32->pl_syscall_code = pl->pl_syscall_code;
+ pl32->pl_syscall_narg = pl->pl_syscall_narg;
}
#endif /* COMPAT_FREEBSD32 */
@@ -1211,6 +1215,13 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
pl->pl_sigmask = td2->td_sigmask;
pl->pl_siglist = td2->td_siglist;
strcpy(pl->pl_tdname, td2->td_name);
+ if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
+ pl->pl_syscall_code = td2->td_dbg_sc_code;
+ pl->pl_syscall_narg = td2->td_dbg_sc_narg;
+ } else {
+ pl->pl_syscall_code = 0;
+ pl->pl_syscall_narg = 0;
+ }
#ifdef COMPAT_FREEBSD32
if (wrap32)
ptrace_lwpinfo_to32(pl, pl32);
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 62c4b05c0061..ae01bbf119e8 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -174,6 +174,7 @@ struct procdesc;
struct racct;
struct sbuf;
struct sleepqueue;
+struct syscall_args;
struct td_sched;
struct thread;
struct trapframe;
@@ -282,6 +283,8 @@ struct thread {
int td_no_sleeping; /* (k) Sleeping disabled count. */
int td_dom_rr_idx; /* (k) RR Numa domain selection. */
void *td_su; /* (k) FFS SU private */
+ u_int td_dbg_sc_code; /* (c) Syscall code to debugger. */
+ u_int td_dbg_sc_narg; /* (c) Syscall arg count to debugger.*/
#define td_endzero td_sigmask
/* Copied during fork1() or create_thread(). */
@@ -979,7 +982,6 @@ void userret(struct thread *, struct trapframe *);
void cpu_exit(struct thread *);
void exit1(struct thread *, int, int) __dead2;
-struct syscall_args;
int cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa);
void cpu_fork(struct thread *, struct proc *, struct thread *, int);
void cpu_set_fork_handler(struct thread *, void (*)(void *), void *);
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
index e770a0612eac..de4e7a7c1d4d 100644
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -113,6 +113,8 @@ struct ptrace_lwpinfo {
struct __siginfo pl_siginfo; /* siginfo for signal */
char pl_tdname[MAXCOMLEN + 1]; /* LWP name */
int pl_child_pid; /* New child pid */
+ u_int pl_syscall_code;
+ u_int pl_syscall_narg;
};
/* Argument structure for PT_VM_ENTRY. */