git: 4cae9d803a95 - stable/13 - Remove PT_GET_SC_ARGS_ALL
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Date: Mon, 21 Feb 2022 13:48:53 UTC
The branch stable/13 has been updated by trasz:
URL: https://cgit.FreeBSD.org/src/commit/?id=4cae9d803a9562a003d00bf8f7b90674e011bae7
commit 4cae9d803a9562a003d00bf8f7b90674e011bae7
Author: Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2021-09-15 13:24:09 +0000
Commit: Edward Tomasz Napierala <trasz@FreeBSD.org>
CommitDate: 2022-02-21 13:34:16 +0000
Remove PT_GET_SC_ARGS_ALL
Reimplement bdf0f24bb16d556a5b by checking for the caller' ABI in
the implementation of PT_GET_SC_ARGS, and copying out everything if
it is Linuxolator.
Also fix a minor information leak: if PT_GET_SC_ARGS_ALL is done on the
thread reused after other process, it allows to read some number of that
thread last syscall arguments. Clear td_sa.args in thread_alloc().
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D31968
(cherry picked from commit f575573ca57716395ad88b962388a55d755cf6a7)
---
lib/libsysdecode/mktables | 2 +-
sys/amd64/linux/linux_ptrace.c | 18 ++++++++++--------
sys/compat/freebsd32/freebsd32_misc.c | 3 ---
sys/kern/kern_thread.c | 1 +
sys/kern/sys_process.c | 23 ++++-------------------
sys/sys/ptrace.h | 4 ----
6 files changed, 16 insertions(+), 35 deletions(-)
diff --git a/lib/libsysdecode/mktables b/lib/libsysdecode/mktables
index f044784717c0..77cfa15bd1f5 100644
--- a/lib/libsysdecode/mktables
+++ b/lib/libsysdecode/mktables
@@ -116,7 +116,7 @@ gen_table "nfssvcflags" "NFSSVC_[A-Z0-9]+[[:space:]]+0x[0-9]+" "nfs/
gen_table "pathconfname" "_PC_[A-Z4_]+[[:space:]]+[0-9]+" "sys/unistd.h"
gen_table "prio" "PRIO_[A-Z]+[[:space:]]+[0-9]" "sys/resource.h"
gen_table "procctlcmd" "PROC_[A-Z_]+[[:space:]]+[0-9]" "sys/procctl.h" "PROC_TRACE_CTL_"
-gen_table "ptraceop" "PT_[[:alnum:]_]+[[:space:]]+[0-9]+" "sys/ptrace.h" "PT_GET_SC_ARGS_ALL"
+gen_table "ptraceop" "PT_[[:alnum:]_]+[[:space:]]+[0-9]+" "sys/ptrace.h"
gen_table "quotactlcmds" "Q_[A-Z]+[[:space:]]+0x[0-9]+" "ufs/ufs/quota.h"
gen_table "rebootopt" "RB_[A-Z]+[[:space:]]+0x[0-9]+" "sys/reboot.h"
gen_table "rforkflags" "RF[A-Z]+[[:space:]]+\([0-9]+<<[0-9]+\)" "sys/unistd.h"
diff --git a/sys/amd64/linux/linux_ptrace.c b/sys/amd64/linux/linux_ptrace.c
index fa400e0d3529..a29a3310dfcd 100644
--- a/sys/amd64/linux/linux_ptrace.c
+++ b/sys/amd64/linux/linux_ptrace.c
@@ -578,17 +578,19 @@ linux_ptrace_get_syscall_info(struct thread *td, pid_t pid,
si.op = LINUX_PTRACE_SYSCALL_INFO_ENTRY;
si.entry.nr = lwpinfo.pl_syscall_code;
/*
- * The reason for using PT_GET_SC_ARGS_ALL instead
- * of PT_GET_SC_ARGS is to emulate Linux bug which strace(1)
- * depends on: at initialization it tests whether ptrace works
- * by calling close(2), or some other single-argument syscall,
- * _with six arguments_, and then verifies whether it can
- * fetch them all using this API; otherwise it bails out.
+ * The use of PT_GET_SC_ARGS there is special,
+ * implementation of PT_GET_SC_ARGS for Linux-ABI
+ * callers emulates Linux bug which strace(1) depends
+ * on: at initialization it tests whether ptrace works
+ * by calling close(2), or some other single-argument
+ * syscall, _with six arguments_, and then verifies
+ * whether it can fetch them all using this API;
+ * otherwise it bails out.
*/
- error = kern_ptrace(td, PT_GET_SC_ARGS_ALL, pid,
+ error = kern_ptrace(td, PT_GET_SC_ARGS, pid,
&si.entry.args, sizeof(si.entry.args));
if (error != 0) {
- linux_msg(td, "PT_GET_SC_ARGS_ALL failed with error %d",
+ linux_msg(td, "PT_GET_SC_ARGS failed with error %d",
error);
return (error);
}
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index b7128debd97f..e56ab423f538 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -1025,9 +1025,6 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap)
r.pc.pc_limit = PAIR32TO64(off_t, r32.pc.pc_limit);
data = sizeof(r.pc);
break;
- case PT_GET_SC_ARGS_ALL:
- error = EINVAL;
- break;
default:
addr = uap->addr;
break;
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index 48aac8e057b8..54254112b376 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -761,6 +761,7 @@ thread_alloc(int pages)
return (NULL);
}
td->td_tid = tid;
+ bzero(&td->td_sa.args, sizeof(td->td_sa.args));
cpu_thread_alloc(td);
EVENTHANDLER_DIRECT_INVOKE(thread_ctor, td);
return (td);
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 75d950a57057..1b9c00179bda 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -532,9 +532,6 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap)
else
error = copyin(uap->addr, &r.pc, uap->data);
break;
- case PT_GET_SC_ARGS_ALL:
- error = EINVAL;
- break;
default:
addr = uap->addr;
break;
@@ -716,7 +713,6 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
case PT_SET_EVENT_MASK:
case PT_DETACH:
case PT_GET_SC_ARGS:
- case PT_GET_SC_ARGS_ALL:
sx_xlock(&proctree_lock);
proctree_locked = true;
break;
@@ -1016,21 +1012,10 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
break;
}
bzero(addr, sizeof(td2->td_sa.args));
- bcopy(td2->td_sa.args, addr, td2->td_sa.callp->sy_narg *
- sizeof(register_t));
- break;
-
- case PT_GET_SC_ARGS_ALL:
- CTR1(KTR_PTRACE, "PT_GET_SC_ARGS_ALL: pid %d", p->p_pid);
- if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
-#ifdef COMPAT_FREEBSD32
- || (wrap32 && !safe)
-#endif
- ) {
- error = EINVAL;
- break;
- }
- bcopy(td2->td_sa.args, addr, sizeof(td2->td_sa.args));
+ /* See the explanation in linux_ptrace_get_syscall_info(). */
+ bcopy(td2->td_sa.args, addr, SV_PROC_ABI(td->td_proc) ==
+ SV_ABI_LINUX ? sizeof(td2->td_sa.args) :
+ td2->td_sa.callp->sy_narg * sizeof(register_t));
break;
case PT_GET_SC_RET:
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
index de7a49576c30..4cd7a3fceaec 100644
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -86,10 +86,6 @@
#define PT_VM_TIMESTAMP 40 /* Get VM version (timestamp) */
#define PT_VM_ENTRY 41 /* Get VM map (entry) */
-#ifdef _KERNEL
-#define PT_GET_SC_ARGS_ALL 42 /* Used by linux(4) */
-#endif
-
#define PT_FIRSTMACH 64 /* for machine-specific requests */
#include <machine/ptrace.h> /* machine-specific requests, if any */