Revision 0f399305cd31e5c813086eaa264f7f47e205c10e authored by Julian Wiedmann on 18 December 2019, 15:32:27 UTC, committed by David S. Miller on 21 December 2019, 05:00:27 UTC
When managing the promiscuous mode during an RX modeset, qeth caches the current HW state to avoid repeated programming of the same state on each modeset. But while tearing down a device, we forget to clear the cached state. So when the device is later set online again, the initial RX modeset doesn't program the promiscuous mode since we believe it is already enabled. Fix this by clearing the cached state in the tear-down path. Note that for the SBP variant of promiscuous mode, this accidentally works right now because we unconditionally restore the SBP role while re-initializing. Fixes: 4a71df50047f ("qeth: new qeth device driver") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 2e3d7fa
bug.c
// SPDX-License-Identifier: GPL-2.0
/*
Generic support for BUG()
This respects the following config options:
CONFIG_BUG - emit BUG traps. Nothing happens without this.
CONFIG_GENERIC_BUG - enable this code.
CONFIG_GENERIC_BUG_RELATIVE_POINTERS - use 32-bit pointers relative to
the containing struct bug_entry for bug_addr and file.
CONFIG_DEBUG_BUGVERBOSE - emit full file+line information for each BUG
CONFIG_BUG and CONFIG_DEBUG_BUGVERBOSE are potentially user-settable
(though they're generally always on).
CONFIG_GENERIC_BUG is set by each architecture using this code.
To use this, your architecture must:
1. Set up the config options:
- Enable CONFIG_GENERIC_BUG if CONFIG_BUG
2. Implement BUG (and optionally BUG_ON, WARN, WARN_ON)
- Define HAVE_ARCH_BUG
- Implement BUG() to generate a faulting instruction
- NOTE: struct bug_entry does not have "file" or "line" entries
when CONFIG_DEBUG_BUGVERBOSE is not enabled, so you must generate
the values accordingly.
3. Implement the trap
- In the illegal instruction trap handler (typically), verify
that the fault was in kernel mode, and call report_bug()
- report_bug() will return whether it was a false alarm, a warning,
or an actual bug.
- You must implement the is_valid_bugaddr(bugaddr) callback which
returns true if the eip is a real kernel address, and it points
to the expected BUG trap instruction.
Jeremy Fitzhardinge <jeremy@goop.org> 2006
*/
#define pr_fmt(fmt) fmt
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/sched.h>
#include <linux/rculist.h>
extern struct bug_entry __start___bug_table[], __stop___bug_table[];
static inline unsigned long bug_addr(const struct bug_entry *bug)
{
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
return bug->bug_addr;
#else
return (unsigned long)bug + bug->bug_addr_disp;
#endif
}
#ifdef CONFIG_MODULES
/* Updates are protected by module mutex */
static LIST_HEAD(module_bug_list);
static struct bug_entry *module_find_bug(unsigned long bugaddr)
{
struct module *mod;
struct bug_entry *bug = NULL;
rcu_read_lock_sched();
list_for_each_entry_rcu(mod, &module_bug_list, bug_list) {
unsigned i;
bug = mod->bug_table;
for (i = 0; i < mod->num_bugs; ++i, ++bug)
if (bugaddr == bug_addr(bug))
goto out;
}
bug = NULL;
out:
rcu_read_unlock_sched();
return bug;
}
void module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
char *secstrings;
unsigned int i;
lockdep_assert_held(&module_mutex);
mod->bug_table = NULL;
mod->num_bugs = 0;
/* Find the __bug_table section, if present */
secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (i = 1; i < hdr->e_shnum; i++) {
if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table"))
continue;
mod->bug_table = (void *) sechdrs[i].sh_addr;
mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);
break;
}
/*
* Strictly speaking this should have a spinlock to protect against
* traversals, but since we only traverse on BUG()s, a spinlock
* could potentially lead to deadlock and thus be counter-productive.
* Thus, this uses RCU to safely manipulate the bug list, since BUG
* must run in non-interruptive state.
*/
list_add_rcu(&mod->bug_list, &module_bug_list);
}
void module_bug_cleanup(struct module *mod)
{
lockdep_assert_held(&module_mutex);
list_del_rcu(&mod->bug_list);
}
#else
static inline struct bug_entry *module_find_bug(unsigned long bugaddr)
{
return NULL;
}
#endif
struct bug_entry *find_bug(unsigned long bugaddr)
{
struct bug_entry *bug;
for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
if (bugaddr == bug_addr(bug))
return bug;
return module_find_bug(bugaddr);
}
enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
{
struct bug_entry *bug;
const char *file;
unsigned line, warning, once, done;
if (!is_valid_bugaddr(bugaddr))
return BUG_TRAP_TYPE_NONE;
bug = find_bug(bugaddr);
if (!bug)
return BUG_TRAP_TYPE_NONE;
file = NULL;
line = 0;
warning = 0;
if (bug) {
#ifdef CONFIG_DEBUG_BUGVERBOSE
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
file = bug->file;
#else
file = (const char *)bug + bug->file_disp;
#endif
line = bug->line;
#endif
warning = (bug->flags & BUGFLAG_WARNING) != 0;
once = (bug->flags & BUGFLAG_ONCE) != 0;
done = (bug->flags & BUGFLAG_DONE) != 0;
if (warning && once) {
if (done)
return BUG_TRAP_TYPE_WARN;
/*
* Since this is the only store, concurrency is not an issue.
*/
bug->flags |= BUGFLAG_DONE;
}
}
/*
* BUG() and WARN_ON() families don't print a custom debug message
* before triggering the exception handler, so we must add the
* "cut here" line now. WARN() issues its own "cut here" before the
* extra debugging message it writes before triggering the handler.
*/
if ((bug->flags & BUGFLAG_NO_CUT_HERE) == 0)
printk(KERN_DEFAULT CUT_HERE);
if (warning) {
/* this is a WARN_ON rather than BUG/BUG_ON */
__warn(file, line, (void *)bugaddr, BUG_GET_TAINT(bug), regs,
NULL);
return BUG_TRAP_TYPE_WARN;
}
if (file)
pr_crit("kernel BUG at %s:%u!\n", file, line);
else
pr_crit("Kernel BUG at %pB [verbose debug info unavailable]\n",
(void *)bugaddr);
return BUG_TRAP_TYPE_BUG;
}
static void clear_once_table(struct bug_entry *start, struct bug_entry *end)
{
struct bug_entry *bug;
for (bug = start; bug < end; bug++)
bug->flags &= ~BUGFLAG_DONE;
}
void generic_bug_clear_once(void)
{
#ifdef CONFIG_MODULES
struct module *mod;
rcu_read_lock_sched();
list_for_each_entry_rcu(mod, &module_bug_list, bug_list)
clear_once_table(mod->bug_table,
mod->bug_table + mod->num_bugs);
rcu_read_unlock_sched();
#endif
clear_once_table(__start___bug_table, __stop___bug_table);
}
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