sh: Make syscall tracer use tracehook notifiers, add TIF_NOTIFY_RESUME.
This follows the changes in commits:
7d6d637dac2050f30a1b57b0a3dc5de4a10616ba
4f72c4279eab1e5f3ed1ac4e55d4527617582392
on powerpc. Adding in TIF_NOTIFY_RESUME, and cleaning up the syscall
tracing to be more generic. This is an incremental step to turning
on tracehook, as well as unifying more of the ptrace and signal code
across the 32/64 split.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/cpu/sh5/entry.S b/arch/sh/kernel/cpu/sh5/entry.S
index bba331d..04c7da9 100644
--- a/arch/sh/kernel/cpu/sh5/entry.S
+++ b/arch/sh/kernel/cpu/sh5/entry.S
@@ -987,11 +987,11 @@
work_notifysig:
gettr tr1, LINK
- movi do_signal, r6
+ movi do_notify_resume, r6
ptabs r6, tr0
or SP, ZERO, r2
- or ZERO, ZERO, r3
- blink tr0, LINK /* Call do_signal(regs, 0), return here */
+ or r7, ZERO, r3
+ blink tr0, LINK /* Call do_notify_resume(regs, current_thread_info->flags), return here */
restore_all:
/* Do prefetches */
@@ -1305,13 +1305,15 @@
beq/l r6, ZERO, tr0
/* Trace it by calling syscall_trace before and after */
- movi syscall_trace, r4
+ movi do_syscall_trace_enter, r4
or SP, ZERO, r2
- or ZERO, ZERO, r3
ptabs r4, tr0
blink tr0, LINK
- /* Reload syscall number as r5 is trashed by syscall_trace */
+ /* Save the retval */
+ st.q SP, FRAME_R(2), r2
+
+ /* Reload syscall number as r5 is trashed by do_syscall_trace_enter */
ld.q SP, FRAME_S(FSYSCALL_ID), r5
andi r5, 0x1ff, r5
@@ -1343,9 +1345,8 @@
/* We get back here only if under trace */
st.q SP, FRAME_R(9), r2 /* Save return value */
- movi syscall_trace, LINK
+ movi do_syscall_trace_leave, LINK
or SP, ZERO, r2
- movi 1, r3
ptabs LINK, tr0
blink tr0, LINK
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
index a34417c..0bc17de 100644
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -211,10 +211,8 @@
nop
#endif
sti
- ! XXX setup arguments...
mov r15, r4
- mov #1, r5
- mov.l 4f, r0 ! do_syscall_trace
+ mov.l 8f, r0 ! do_syscall_trace_leave
jsr @r0
nop
bra resume_userspace
@@ -223,12 +221,11 @@
.align 2
syscall_trace_entry:
! Yes it is traced.
- ! XXX setup arguments...
mov r15, r4
- mov #0, r5
- mov.l 4f, r11 ! Call do_syscall_trace which notifies
+ mov.l 7f, r11 ! Call do_syscall_trace_enter which notifies
jsr @r11 ! superior (will chomp R[0-7])
nop
+ mov.l r0, @(OFF_R0,r15) ! Save return value
! Reload R0-R4 from kernel stack, where the
! parent may have modified them using
! ptrace(POKEUSR). (Note that R0-R2 are
@@ -389,8 +386,9 @@
#endif
2: .long NR_syscalls
3: .long sys_call_table
-4: .long do_syscall_trace
#ifdef CONFIG_TRACE_IRQFLAGS
5: .long trace_hardirqs_on
6: .long trace_hardirqs_off
#endif
+7: .long do_syscall_trace_enter
+8: .long do_syscall_trace_leave
diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index ff66f97..f48769b 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -21,6 +21,7 @@
#include <linux/io.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
+#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
@@ -216,41 +217,38 @@
return ret;
}
-asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
- struct task_struct *tsk = current;
+ long ret = 0;
secure_computing(regs->regs[0]);
- if (unlikely(current->audit_context) && entryexit)
- audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
- regs->regs[0]);
+ if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+ tracehook_report_syscall_entry(regs))
+ /*
+ * Tracing decided this syscall should not happen.
+ * We'll return a bogus call number to get an ENOSYS
+ * error, but leave the original number in regs->regs[0].
+ */
+ ret = -1L;
- if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
- !test_thread_flag(TIF_SINGLESTEP))
- goto out;
- if (!(tsk->ptrace & PT_PTRACED))
- goto out;
-
- /* the 0x80 provides a way for the tracing parent to distinguish
- between a syscall stop and SIGTRAP delivery */
- ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) &&
- !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
-
- /*
- * this isn't the same as continuing with a signal, but it will do
- * for normal use. strace only continues with a signal if the
- * stopping signal is not SIGTRAP. -brl
- */
- if (tsk->exit_code) {
- send_sig(tsk->exit_code, tsk, 1);
- tsk->exit_code = 0;
- }
-
-out:
- if (unlikely(current->audit_context) && !entryexit)
+ if (unlikely(current->audit_context))
audit_syscall_entry(AUDIT_ARCH_SH, regs->regs[3],
regs->regs[4], regs->regs[5],
regs->regs[6], regs->regs[7]);
+ return ret ?: regs->regs[0];
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+ int step;
+
+ if (unlikely(current->audit_context))
+ audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
+ regs->regs[0]);
+
+ step = test_thread_flag(TIF_SINGLESTEP);
+ if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+ tracehook_report_syscall_exit(regs, step);
}
diff --git a/arch/sh/kernel/ptrace_64.c b/arch/sh/kernel/ptrace_64.c
index 108f396..236d8be 100644
--- a/arch/sh/kernel/ptrace_64.c
+++ b/arch/sh/kernel/ptrace_64.c
@@ -28,6 +28,7 @@
#include <linux/syscalls.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
+#include <linux/tracehook.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -221,40 +222,37 @@
return sys_ptrace(request, pid, addr, data);
}
-asmlinkage void syscall_trace(struct pt_regs *regs, int entryexit)
+asmlinkage long long do_syscall_trace_enter(struct pt_regs *regs)
{
- struct task_struct *tsk = current;
+ long long ret = 0;
secure_computing(regs->regs[9]);
- if (unlikely(current->audit_context) && entryexit)
- audit_syscall_exit(AUDITSC_RESULT(regs->regs[9]),
- regs->regs[9]);
+ if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+ tracehook_report_syscall_entry(regs))
+ /*
+ * Tracing decided this syscall should not happen.
+ * We'll return a bogus call number to get an ENOSYS
+ * error, but leave the original number in regs->regs[0].
+ */
+ ret = -1LL;
- if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
- !test_thread_flag(TIF_SINGLESTEP))
- goto out;
- if (!(tsk->ptrace & PT_PTRACED))
- goto out;
-
- ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) &&
- !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
-
- /*
- * this isn't the same as continuing with a signal, but it will do
- * for normal use. strace only continues with a signal if the
- * stopping signal is not SIGTRAP. -brl
- */
- if (tsk->exit_code) {
- send_sig(tsk->exit_code, tsk, 1);
- tsk->exit_code = 0;
- }
-
-out:
- if (unlikely(current->audit_context) && !entryexit)
+ if (unlikely(current->audit_context))
audit_syscall_entry(AUDIT_ARCH_SH, regs->regs[1],
regs->regs[2], regs->regs[3],
regs->regs[4], regs->regs[5]);
+
+ return ret ?: regs->regs[9];
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+ if (unlikely(current->audit_context))
+ audit_syscall_exit(AUDITSC_RESULT(regs->regs[9]),
+ regs->regs[9]);
+
+ if (test_thread_flag(TIF_SYSCALL_TRACE))
+ tracehook_report_syscall_exit(regs, 0);
}
/* Called with interrupts disabled */
diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c
index 4bbbde8..51689d2 100644
--- a/arch/sh/kernel/signal_32.c
+++ b/arch/sh/kernel/signal_32.c
@@ -24,6 +24,7 @@
#include <linux/binfmts.h>
#include <linux/freezer.h>
#include <linux/io.h>
+#include <linux/tracehook.h>
#include <asm/system.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
@@ -507,14 +508,13 @@
switch (regs->regs[0]) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
+ no_system_call_restart:
regs->regs[0] = -EINTR;
break;
case -ERESTARTSYS:
- if (!(ka->sa.sa_flags & SA_RESTART)) {
- regs->regs[0] = -EINTR;
- break;
- }
+ if (!(ka->sa.sa_flags & SA_RESTART))
+ goto no_system_call_restart;
/* fallthrough */
case -ERESTARTNOINTR:
regs->regs[0] = save_r0;
@@ -589,12 +589,15 @@
* clear the TIF_RESTORE_SIGMASK flag */
if (test_thread_flag(TIF_RESTORE_SIGMASK))
clear_thread_flag(TIF_RESTORE_SIGMASK);
+
+ tracehook_signal_handler(signr, &info, &ka, regs,
+ test_thread_flag(TIF_SINGLESTEP));
}
return;
}
- no_signal:
+no_signal:
/* Did we come from a system call? */
if (regs->tra >= 0) {
/* Restart the system call - no handlers present */
@@ -618,9 +621,14 @@
}
asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
- __u32 thread_info_flags)
+ unsigned long thread_info_flags)
{
/* deal with pending signal delivery */
- if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+ if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs, save_r0);
+
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
}
diff --git a/arch/sh/kernel/signal_64.c b/arch/sh/kernel/signal_64.c
index 552eb81..1d62dfe 100644
--- a/arch/sh/kernel/signal_64.c
+++ b/arch/sh/kernel/signal_64.c
@@ -22,6 +22,7 @@
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
+#include <linux/tracehook.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -42,7 +43,84 @@
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+static int do_signal(struct pt_regs *regs, sigset_t *oldset)
+{
+ siginfo_t info;
+ int signr;
+ struct k_sigaction ka;
+
+ /*
+ * We want the common case to go fast, which
+ * is why we may in certain cases get here from
+ * kernel mode. Just return without doing anything
+ * if so.
+ */
+ if (!user_mode(regs))
+ return 1;
+
+ if (try_to_freeze())
+ goto no_signal;
+
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ oldset = ¤t->saved_sigmask;
+ else if (!oldset)
+ oldset = ¤t->blocked;
+
+ signr = get_signal_to_deliver(&info, &ka, regs, 0);
+
+ if (signr > 0) {
+ /* Whee! Actually deliver the signal. */
+ handle_signal(signr, &info, &ka, oldset, regs);
+
+ /*
+ * If a signal was successfully delivered, the saved sigmask
+ * is in its frame, and we can clear the TIF_RESTORE_SIGMASK
+ * flag.
+ */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+
+ tracehook_signal_handler(signr, &info, &ka, regs, 0);
+ return 1;
+ }
+
+no_signal:
+ /* Did we come from a system call? */
+ if (regs->syscall_nr >= 0) {
+ /* Restart the system call - no handlers present */
+ switch (regs->regs[REG_RET]) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ /* Decode Syscall # */
+ regs->regs[REG_RET] = regs->syscall_nr;
+ regs->pc -= 4;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ regs->regs[REG_RET] = __NR_restart_syscall;
+ regs->pc -= 4;
+ break;
+ }
+ }
+
+ /* No signal to deliver -- put the saved sigmask back */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
+ }
+
+ return 0;
+}
/*
* Atomically swap in the new signal mask, and wait for a signal.
@@ -643,14 +721,13 @@
switch (regs->regs[REG_RET]) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
+ no_system_call_restart:
regs->regs[REG_RET] = -EINTR;
break;
case -ERESTARTSYS:
- if (!(ka->sa.sa_flags & SA_RESTART)) {
- regs->regs[REG_RET] = -EINTR;
- break;
- }
+ if (!(ka->sa.sa_flags & SA_RESTART))
+ goto no_system_call_restart;
/* fallthrough */
case -ERESTARTNOINTR:
/* Decode syscall # */
@@ -673,80 +750,13 @@
spin_unlock_irq(¤t->sighand->siglock);
}
-/*
- * Note that 'init' is a special process: it doesn't get signals it doesn't
- * want to handle. Thus you cannot kill init even with a SIGKILL even by
- * mistake.
- *
- * Note that we go through the signals twice: once to check the signals that
- * the kernel can handle, and then we build all the user-level signal handling
- * stack-frames in one go after that.
- */
-int do_signal(struct pt_regs *regs, sigset_t *oldset)
+asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
{
- siginfo_t info;
- int signr;
- struct k_sigaction ka;
+ if (thread_info_flags & _TIF_SIGPENDING)
+ do_signal(regs, 0);
- /*
- * We want the common case to go fast, which
- * is why we may in certain cases get here from
- * kernel mode. Just return without doing anything
- * if so.
- */
- if (!user_mode(regs))
- return 1;
-
- if (try_to_freeze())
- goto no_signal;
-
- if (test_thread_flag(TIF_RESTORE_SIGMASK))
- oldset = ¤t->saved_sigmask;
- else if (!oldset)
- oldset = ¤t->blocked;
-
- signr = get_signal_to_deliver(&info, &ka, regs, 0);
-
- if (signr > 0) {
- /* Whee! Actually deliver the signal. */
- handle_signal(signr, &info, &ka, oldset, regs);
-
- /*
- * If a signal was successfully delivered, the saved sigmask
- * is in its frame, and we can clear the TIF_RESTORE_SIGMASK
- * flag.
- */
- if (test_thread_flag(TIF_RESTORE_SIGMASK))
- clear_thread_flag(TIF_RESTORE_SIGMASK);
-
- return 1;
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
}
-
-no_signal:
- /* Did we come from a system call? */
- if (regs->syscall_nr >= 0) {
- /* Restart the system call - no handlers present */
- switch (regs->regs[REG_RET]) {
- case -ERESTARTNOHAND:
- case -ERESTARTSYS:
- case -ERESTARTNOINTR:
- /* Decode Syscall # */
- regs->regs[REG_RET] = regs->syscall_nr;
- regs->pc -= 4;
- break;
-
- case -ERESTART_RESTARTBLOCK:
- regs->regs[REG_RET] = __NR_restart_syscall;
- regs->pc -= 4;
- break;
- }
- }
-
- /* No signal to deliver -- put the saved sigmask back */
- if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
- clear_thread_flag(TIF_RESTORE_SIGMASK);
- sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
- }
-
- return 0;
}