libvirt/src/util/virscsi.h
Daniel P. Berrange 407a281a8e Revert "Prevent more compiler optimization of mockable functions"
This reverts commit e4b980c853.

When a binary links against a .a archive (as opposed to a shared library),
any symbols which are marked as 'weak' get silently dropped. As a result
when the binary later runs, those 'weak' functions have an address of
0x0 and thus crash when run.

This happened with virtlogd and virtlockd because they don't link to
libvirt.so, but instead just libvirt_util.a and libvirt_rpc.a. The
virRandomBits symbols was weak and so left out of the virtlogd &
virtlockd binaries, despite being required by virHashTable functions.

Various other binaries like libvirt_lxc, libvirt_iohelper, etc also
link directly to .a files instead of libvirt.so, so are potentially
at risk of dropping symbols leading to a later runtime crash.

This is normal linker behaviour because a weak symbol is not treated
as undefined, so nothing forces it to be pulled in from the .a You
have to force the linker to pull in weak symbols using -u$SYMNAME
which is not a practical approach.

This risk is silent bad linkage that affects runtime behaviour is
not acceptable for a fix that was merely trying to fix the test
suite. So stop using __weak__ again.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-13 13:07:06 +01:00

99 lines
4.0 KiB
C

/*
* virscsi.h: helper APIs for managing host SCSI devices
*
* Copyright (C) 2013 Fujitsu, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
* Authors:
* Han Cheng <hanc.fnst@cn.fujitsu.com>
*/
#ifndef __VIR_SCSI_H__
# define __VIR_SCSI_H__
# include "internal.h"
# include "virobject.h"
typedef struct _virSCSIDevice virSCSIDevice;
typedef virSCSIDevice *virSCSIDevicePtr;
typedef struct _virSCSIDeviceList virSCSIDeviceList;
typedef virSCSIDeviceList *virSCSIDeviceListPtr;
char *virSCSIDeviceGetSgName(const char *sysfs_prefix,
const char *adapter,
unsigned int bus,
unsigned int target,
unsigned long long unit) ATTRIBUTE_NOINLINE;
char *virSCSIDeviceGetDevName(const char *sysfs_prefix,
const char *adapter,
unsigned int bus,
unsigned int target,
unsigned long long unit);
virSCSIDevicePtr virSCSIDeviceNew(const char *sysfs_prefix,
const char *adapter,
unsigned int bus,
unsigned int target,
unsigned long long unit,
bool readonly,
bool shareable);
void virSCSIDeviceFree(virSCSIDevicePtr dev);
int virSCSIDeviceSetUsedBy(virSCSIDevicePtr dev,
const char *drvname,
const char *domname);
bool virSCSIDeviceIsAvailable(virSCSIDevicePtr dev);
const char *virSCSIDeviceGetName(virSCSIDevicePtr dev);
const char *virSCSIDeviceGetPath(virSCSIDevicePtr dev);
unsigned int virSCSIDeviceGetAdapter(virSCSIDevicePtr dev);
unsigned int virSCSIDeviceGetBus(virSCSIDevicePtr dev);
unsigned int virSCSIDeviceGetTarget(virSCSIDevicePtr dev);
unsigned long long virSCSIDeviceGetUnit(virSCSIDevicePtr dev);
bool virSCSIDeviceGetReadonly(virSCSIDevicePtr dev);
bool virSCSIDeviceGetShareable(virSCSIDevicePtr dev);
/*
* Callback that will be invoked once for each file
* associated with / used for SCSI host device access.
*
* Should return 0 if successfully processed, or
* -1 to indicate error and abort iteration
*/
typedef int (*virSCSIDeviceFileActor)(virSCSIDevicePtr dev,
const char *path, void *opaque);
int virSCSIDeviceFileIterate(virSCSIDevicePtr dev,
virSCSIDeviceFileActor actor,
void *opaque);
virSCSIDeviceListPtr virSCSIDeviceListNew(void);
int virSCSIDeviceListAdd(virSCSIDeviceListPtr list,
virSCSIDevicePtr dev);
virSCSIDevicePtr virSCSIDeviceListGet(virSCSIDeviceListPtr list,
int idx);
size_t virSCSIDeviceListCount(virSCSIDeviceListPtr list);
virSCSIDevicePtr virSCSIDeviceListSteal(virSCSIDeviceListPtr list,
virSCSIDevicePtr dev);
void virSCSIDeviceListDel(virSCSIDeviceListPtr list,
virSCSIDevicePtr dev,
const char *drvname,
const char *domname);
virSCSIDevicePtr virSCSIDeviceListFind(virSCSIDeviceListPtr list,
virSCSIDevicePtr dev);
#endif /* __VIR_SCSI_H__ */