Add TIF_FD_SLOTS and test it after the untraced system call has stored its return value. A task that reserved descriptors joins the traced path, where syscall_trace_exit() commits them before audit and the ptrace exit stop.
Signed-off-by: Christian Brauner (Amutable) <[email protected]> --- arch/csky/include/asm/thread_info.h | 2 ++ arch/csky/kernel/entry.S | 9 +++++++++ arch/csky/kernel/ptrace.c | 4 ++++ 3 files changed, 15 insertions(+) diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h index fdd4f8ad45ac..59109ce64695 100644 --- a/arch/csky/include/asm/thread_info.h +++ b/arch/csky/include/asm/thread_info.h @@ -61,6 +61,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SYSCALL_TRACEPOINT 5 /* syscall tracepoint instrumentation */ #define TIF_SYSCALL_AUDIT 6 /* syscall auditing */ #define TIF_NOTIFY_SIGNAL 7 /* signal notifications exist */ +#define TIF_FD_SLOTS 8 /* syscall prepared descriptors */ #define TIF_POLLING_NRFLAG 16 /* poll_idle() is TIF_NEED_RESCHED */ #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ #define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */ @@ -73,6 +74,7 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) +#define _TIF_FD_SLOTS (1 << TIF_FD_SLOTS) #define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_MEMDIE (1 << TIF_MEMDIE) diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index 3261f46f2244..6ff3074b9787 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -80,6 +80,15 @@ ENTRY(csky_systemcall) jsr syscallid #endif stw a0, (sp, LSAVE_A0) /* Save return value */ + /* descriptors reserved by the syscall are committed in syscall_trace_exit() */ + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + ldw r10, (r9, TINFO_FLAGS) + lrw r9, _TIF_FD_SLOTS + and r10, r9 + cmpnei r10, 0 + bt 1f jmpi ret_from_exception csky_syscall_trace: diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index ee2867a1576e..b19fef9d396d 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -4,6 +4,7 @@ #include <linux/audit.h> #include <linux/elf.h> #include <linux/errno.h> +#include <linux/file.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/ptrace.h> @@ -335,6 +336,9 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs) asmlinkage void syscall_trace_exit(struct pt_regs *regs) { + if (test_thread_flag(TIF_FD_SLOTS)) + fd_slots_commit(regs); + audit_syscall_exit(regs); if (test_thread_flag(TIF_SYSCALL_TRACE)) -- 2.53.0
