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Require the STACK option for code that captures stacks of running threads.

Browse Source 
stack_machdep.c is compiled if either of the DDB or STACK options is
specified, but stack_save_td_running() isn't useable from DDB. Moreover,
stack_save_td_running() works by raising an NMI on the CPU running the
target thread, and the corresponding handler is compiled only if STACK is
configured.

Reported by:	kib
MFC after:	1 week
This commit is contained in:
markj 2016-12-06 22:48:28 +00:00
parent fe5a91c61d
commit d4d64ed3c6
1 changed files with 14 additions and 2 deletions
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16
sys/x86/x86/stack_machdep.c
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@ -28,6 +28,8 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_stack.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
@ -59,6 +61,7 @@ typedef struct i386_frame *x86_frame_t;
typedef struct amd64_frame *x86_frame_t;
#endif
#ifdef STACK
static struct stack *nmi_stack;
static volatile struct thread *nmi_pending;
@ -66,6 +69,7 @@ static volatile struct thread *nmi_pending;
static struct mtx nmi_lock;
MTX_SYSINIT(nmi_lock, &nmi_lock, "stack_nmi", MTX_SPIN);
#endif
#endif
static void
stack_capture(struct thread *td, struct stack *st, register_t fp)
@ -95,6 +99,7 @@ int
stack_nmi_handler(struct trapframe *tf)
{
#ifdef STACK
/* Don't consume an NMI that wasn't meant for us. */
if (nmi_stack == NULL || curthread != nmi_pending)
return (0);
@ -107,6 +112,9 @@ stack_nmi_handler(struct trapframe *tf)
atomic_store_rel_ptr((long *)&nmi_pending, (long)NULL);
return (1);
#else
return (0);
#endif
}
void
@ -125,6 +133,7 @@ int
stack_save_td_running(struct stack *st, struct thread *td)
{
#ifdef STACK
THREAD_LOCK_ASSERT(td, MA_OWNED);
MPASS(TD_IS_RUNNING(td));
@ -148,10 +157,13 @@ stack_save_td_running(struct stack *st, struct thread *td)
if (st->depth == 0)
/* We interrupted a thread in user mode. */
return (EAGAIN);
#else
#else /* !SMP */
KASSERT(0, ("curthread isn't running"));
#endif
#endif /* SMP */
return (0);
#else /* !STACK */
return (EOPNOTSUPP);
#endif /* STACK */
}
void