freebsd-skq/sys/x86/include/stack.h
markj 97176dfe26 Reimplement stack capture of running threads on i386 and amd64.
After r355784 the td_oncpu field is no longer synchronized by the thread
lock, so the stack capture interrupt cannot be delievered precisely.
Fix this using a loop which drops the thread lock and restarts if the
wrong thread was sampled from the stack capture interrupt handler.

Change the implementation to use a regular interrupt instead of an NMI.
Now that we drop the thread lock, there is no advantage to the latter.

Simplify the KPIs.  Remove stack_save_td_running() and add a return
value to stack_save_td().  On platforms that do not support stack
capture of running threads, stack_save_td() returns EOPNOTSUPP.  If the
target thread is running in user mode, stack_save_td() returns EBUSY.

Reviewed by:	kib
Reported by:	mjg, pho
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23355
2020-01-31 15:43:33 +00:00

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C

/*-
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
#ifndef _X86_STACK_H
#define _X86_STACK_H
/*
* Stack trace.
*/
#ifdef __i386__
struct i386_frame {
struct i386_frame *f_frame;
u_int f_retaddr;
u_int f_arg0;
};
#endif
#ifdef __amd64__
struct amd64_frame {
struct amd64_frame *f_frame;
u_long f_retaddr;
};
struct i386_frame {
uint32_t f_frame;
uint32_t f_retaddr;
uint32_t f_arg0;
};
#endif /* __amd64__ */
#ifdef _KERNEL
void stack_capture_intr(void);
#endif
#endif /* !_X86_STACK_H */