vmlinux.o: warning: objtool: exc_debug()+0xbb: call to
clear_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: noist_exc_debug()+0x55: call to
clear_ti_thread_flag.constprop.0() leaves .noinstr.text section
Rework things so that handle_debug() looses the noinstr and move the
clear_thread_flag() into that.
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
arch/x86/kernel/traps.c | 55 +++++++++++++++++++++++-------------------------
1 file changed, 27 insertions(+), 28 deletions(-)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -775,26 +775,44 @@ static __always_inline void debug_exit(u
*
* May run on IST stack.
*/
-static void noinstr handle_debug(struct pt_regs *regs, unsigned long dr6,
- bool user_icebp)
+static void handle_debug(struct pt_regs *regs, unsigned long dr6, bool user)
{
struct task_struct *tsk = current;
+ bool user_icebp;
int si_code;
+ /*
+ * The SDM says "The processor clears the BTF flag when it
+ * generates a debug exception." Clear TIF_BLOCKSTEP to keep
+ * TIF_BLOCKSTEP in sync with the hardware BTF flag.
+ */
+ clear_thread_flag(TIF_BLOCKSTEP);
+
+ /*
+ * If DR6 is zero, no point in trying to handle it. The kernel is
+ * not using INT1.
+ */
+ if (!user && !dr6)
+ return;
+
+ /*
+ * If dr6 has no reason to give us about the origin of this trap,
+ * then it's very likely the result of an icebp/int01 trap.
+ * User wants a sigtrap for that.
+ */
+ user_icebp = user && !dr6;
+
/* Store the virtualized DR6 value */
tsk->thread.debugreg6 = dr6;
- instrumentation_begin();
#ifdef CONFIG_KPROBES
if (kprobe_debug_handler(regs)) {
- instrumentation_end();
return;
}
#endif
if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, 0,
SIGTRAP) == NOTIFY_STOP) {
- instrumentation_end();
return;
}
@@ -825,7 +843,6 @@ static void noinstr handle_debug(struct
out:
cond_local_irq_disable(regs);
- instrumentation_end();
}
static __always_inline void exc_debug_kernel(struct pt_regs *regs,
@@ -834,14 +851,6 @@ static __always_inline void exc_debug_ke
nmi_enter();
instrumentation_begin();
trace_hardirqs_off_finish();
- instrumentation_end();
-
- /*
- * The SDM says "The processor clears the BTF flag when it
- * generates a debug exception." Clear TIF_BLOCKSTEP to keep
- * TIF_BLOCKSTEP in sync with the hardware BTF flag.
- */
- clear_thread_flag(TIF_BLOCKSTEP);
/*
* Catch SYSENTER with TF set and clear DR_STEP. If this hit a
@@ -850,14 +859,8 @@ static __always_inline void exc_debug_ke
if ((dr6 & DR_STEP) && is_sysenter_singlestep(regs))
dr6 &= ~DR_STEP;
- /*
- * If DR6 is zero, no point in trying to handle it. The kernel is
- * not using INT1.
- */
- if (dr6)
- handle_debug(regs, dr6, false);
+ handle_debug(regs, dr6, false);
- instrumentation_begin();
if (regs->flags & X86_EFLAGS_IF)
trace_hardirqs_on_prepare();
instrumentation_end();
@@ -868,14 +871,10 @@ static __always_inline void exc_debug_us
unsigned long dr6)
{
idtentry_enter_user(regs);
- clear_thread_flag(TIF_BLOCKSTEP);
+ instrumentation_begin();
- /*
- * If dr6 has no reason to give us about the origin of this trap,
- * then it's very likely the result of an icebp/int01 trap.
- * User wants a sigtrap for that.
- */
- handle_debug(regs, dr6, !dr6);
+ handle_debug(regs, dr6, true);
+ instrumentation_end();
idtentry_exit_user(regs);
}
