Revision 9ecfe875c4f311618cc918aded716017dcd2ddf1 authored by Karicheri, Muralidharan on 19 February 2016, 17:58:42 UTC, committed by David S. Miller on 22 February 2016, 03:03:15 UTC
The commit 899077791403 ("netcp: try to reduce type confusion in descriptors") introduces a regression in Kernel 4.5-rc1 and it breaks get/set_pad_info() functionality. The TI NETCP driver uses pad0 and pad1 fields of knav_dma_desc to store DMA/MEM buffer pointer and buffer size respectively. And in both cases for Keystone 2 the pointer type size is 32 bit regardless of LAPE enabled or not, because CONFIG_ARCH_DMA_ADDR_T_64BIT originally is not expected to be defined. Unfortunately, above commit changed buffer's pointers save/restore code (get/set_pad_info()) and added intermediate conversation to u64 which works incorrectly on 32bit Keystone 2 and causes TI NETCP driver crash in RX/TX path due to "Unable to handle kernel NULL pointer" exception. This issue was reported and discussed in [1]. Hence, fix it by partially reverting above commit and restoring get/set_pad_info() functionality as it was before. [1] https://www.mail-archive.com/netdev@vger.kernel.org/msg95361.html Cc: Wingman Kwok <w-kwok2@ti.com> Cc: Mugunthan V N <mugunthanvnm@ti.com> CC: David Laight <David.Laight@ACULAB.COM> CC: Arnd Bergmann <arnd@arndb.de> Reported-by: Franklin S Cooper Jr <fcooper@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
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backtracetest.c
/*
* Simple stack backtrace regression test module
*
* (C) Copyright 2008 Intel Corporation
* Author: Arjan van de Ven <arjan@linux.intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*/
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
static void backtrace_test_normal(void)
{
pr_info("Testing a backtrace from process context.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
dump_stack();
}
static DECLARE_COMPLETION(backtrace_work);
static void backtrace_test_irq_callback(unsigned long data)
{
dump_stack();
complete(&backtrace_work);
}
static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);
static void backtrace_test_irq(void)
{
pr_info("Testing a backtrace from irq context.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
init_completion(&backtrace_work);
tasklet_schedule(&backtrace_tasklet);
wait_for_completion(&backtrace_work);
}
#ifdef CONFIG_STACKTRACE
static void backtrace_test_saved(void)
{
struct stack_trace trace;
unsigned long entries[8];
pr_info("Testing a saved backtrace.\n");
pr_info("The following trace is a kernel self test and not a bug!\n");
trace.nr_entries = 0;
trace.max_entries = ARRAY_SIZE(entries);
trace.entries = entries;
trace.skip = 0;
save_stack_trace(&trace);
print_stack_trace(&trace, 0);
}
#else
static void backtrace_test_saved(void)
{
pr_info("Saved backtrace test skipped.\n");
}
#endif
static int backtrace_regression_test(void)
{
pr_info("====[ backtrace testing ]===========\n");
backtrace_test_normal();
backtrace_test_irq();
backtrace_test_saved();
pr_info("====[ end of backtrace testing ]====\n");
return 0;
}
static void exitf(void)
{
}
module_init(backtrace_regression_test);
module_exit(exitf);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
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