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Commit 3b004569 authored by David S. Miller's avatar David S. Miller
Browse files

ipv4: Avoid use of signed integers in fib_trie code. 



GCC emits all kinds of crazy zero extensions when we go from signed
int, to unsigned short, etc. etc.

This transformation has to be legal because:

1) In tkey_extract_bits() in mask_pfx(), the values are used to
   perform shifts, on which negative values are undefined by C.

2) In fib_table_lookup() we perform comparisons with unsigned
   values, constants, and additions.  None of which should
   encounter negative values.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3c7bd1a1

net/ipv4/fib_trie.c

+5 −5
Original line number Diff line number Diff line
@@ -217,12 +217,12 @@ static inline int tnode_child_length(const struct tnode *tn) 
	return 1 << tn->bits;

}



static inline t_key mask_pfx(t_key k, unsigned short l)

static inline t_key mask_pfx(t_key k, unsigned int l)

{

	return (l == 0) ? 0 : k >> (KEYLENGTH-l) << (KEYLENGTH-l);

}



static inline t_key tkey_extract_bits(t_key a, int offset, int bits)

static inline t_key tkey_extract_bits(t_key a, unsigned int offset, unsigned int bits)

{

	if (offset < KEYLENGTH)

		return ((t_key)(a << offset)) >> (KEYLENGTH - bits);
@@ -1378,11 +1378,11 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi *flp, 
	int ret;

	struct rt_trie_node *n;

	struct tnode *pn;

	int pos, bits;

	unsigned int pos, bits;

	t_key key = ntohl(flp->fl4_dst);

	int chopped_off;

	unsigned int chopped_off;

	t_key cindex = 0;

	int current_prefix_length = KEYLENGTH;

	unsigned int current_prefix_length = KEYLENGTH;

	struct tnode *cn;

	t_key pref_mismatch;