Revision 6a6b0b9914e73a8a54253dd5f6f5e5dd5e4a756c authored by Mat Martineau on 21 December 2017, 18:29:09 UTC, committed by David S. Miller on 26 December 2017, 22:25:22 UTC
Using a preprocessor directive to check for CONFIG_IPV6 in the middle of
a DECLARE_EVENT_CLASS macro's arg list causes sparse to report a series
of errors:

./include/trace/events/tcp.h:68:1: error: directive in argument list
./include/trace/events/tcp.h:75:1: error: directive in argument list
./include/trace/events/tcp.h:144:1: error: directive in argument list
./include/trace/events/tcp.h:151:1: error: directive in argument list
./include/trace/events/tcp.h:216:1: error: directive in argument list
./include/trace/events/tcp.h:223:1: error: directive in argument list
./include/trace/events/tcp.h:274:1: error: directive in argument list
./include/trace/events/tcp.h:281:1: error: directive in argument list

Once sparse finds an error, it stops printing warnings for the file it
is checking. This masks any sparse warnings that would normally be
reported for the core TCP code.

Instead, handle the preprocessor conditionals in a couple of auxiliary
macros. This also has the benefit of reducing duplicate code.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 3a33a19
Raw File
min_addr.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/security.h>
#include <linux/sysctl.h>

/* amount of vm to protect from userspace access by both DAC and the LSM*/
unsigned long mmap_min_addr;
/* amount of vm to protect from userspace using CAP_SYS_RAWIO (DAC) */
unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
/* amount of vm to protect from userspace using the LSM = CONFIG_LSM_MMAP_MIN_ADDR */

/*
 * Update mmap_min_addr = max(dac_mmap_min_addr, CONFIG_LSM_MMAP_MIN_ADDR)
 */
static void update_mmap_min_addr(void)
{
#ifdef CONFIG_LSM_MMAP_MIN_ADDR
	if (dac_mmap_min_addr > CONFIG_LSM_MMAP_MIN_ADDR)
		mmap_min_addr = dac_mmap_min_addr;
	else
		mmap_min_addr = CONFIG_LSM_MMAP_MIN_ADDR;
#else
	mmap_min_addr = dac_mmap_min_addr;
#endif
}

/*
 * sysctl handler which just sets dac_mmap_min_addr = the new value and then
 * calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly
 */
int mmap_min_addr_handler(struct ctl_table *table, int write,
			  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	int ret;

	if (write && !capable(CAP_SYS_RAWIO))
		return -EPERM;

	ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);

	update_mmap_min_addr();

	return ret;
}

static int __init init_mmap_min_addr(void)
{
	update_mmap_min_addr();

	return 0;
}
pure_initcall(init_mmap_min_addr);
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