/*===========================================================================
Copyright (c) 1998-2000, The Santa Cruz Operation
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
*Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
*Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
*Neither name of The Santa Cruz Operation nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
=========================================================================*/
/* cscope - interactive C symbol cross-reference
*
* keyword look-up routine for the C symbol scanner
*/
#include "global.h"
#include "lookup.h"
static char const rcsid[] = "$Id: lookup.c,v 1.4 2006/04/21 10:45:48 broeker Exp $";
/* keyword text for fast testing of keywords in the scanner */
char enumtext[] = "enum";
char externtext[] = "extern";
char structtext[] = "struct";
char typedeftext[] = "typedef";
char uniontext[] = "union";
/* This keyword table is also used for keyword text compression. Keywords
* with an index less than the numeric value of a space are replaced with the
* control character corresponding to the index, so they cannot be moved
* without changing the database file version and adding compatibility code
* for old databases.
*/
struct keystruct keyword[] = {
{"", '\0', NULL}, /* dummy entry */
{"#define", ' ', NULL}, /* must be table entry 1 */
{"#include", ' ', NULL}, /* must be table entry 2 */
{"break", '\0', NULL}, /* rarely in cross-reference */
{"case", ' ', NULL},
{"char", ' ', NULL},
{"continue", '\0', NULL}, /* rarely in cross-reference */
{"default", '\0', NULL}, /* rarely in cross-reference */
{"double", ' ', NULL},
{"\t", '\0', NULL}, /* must be the table entry 9 */
{"\n", '\0', NULL}, /* must be the table entry 10 */
{"else", ' ', NULL},
{enumtext, ' ', NULL},
{externtext, ' ', NULL},
{"float", ' ', NULL},
{"for", '(', NULL},
{"goto", ' ', NULL},
{"if", '(', NULL},
{"int", ' ', NULL},
{"long", ' ', NULL},
{"register", ' ', NULL},
{"return", '\0', NULL},
{"short", ' ', NULL},
{"sizeof", '\0', NULL},
{"static", ' ', NULL},
{structtext, ' ', NULL},
{"switch", '(', NULL},
{typedeftext, ' ', NULL},
{uniontext, ' ', NULL},
{"unsigned", ' ', NULL},
{"void", ' ', NULL},
{"while", '(', NULL},
/* these keywords are not compressed */
{"do", '\0', NULL},
{"auto", ' ', NULL},
{"fortran", ' ', NULL},
{"const", ' ', NULL},
{"signed", ' ', NULL},
{"volatile", ' ', NULL},
};
#define KEYWORDS (sizeof(keyword) / sizeof(struct keystruct))
#define HASHMOD (KEYWORDS * 2 + 1)
static struct keystruct *hashtab[HASHMOD]; /* pointer table */
/* put the keywords into the symbol table */
void
initsymtab(void)
{
unsigned int i, j;
struct keystruct *p;
for (i = 1; i < KEYWORDS; ++i) {
p = keyword + i;
j = hash(p->text) % HASHMOD;
p->next = hashtab[j];
hashtab[j] = p;
}
}
/* see if this identifier is a keyword */
char *
lookup(char *ident)
{
struct keystruct *p;
int c;
/* look up the identifier in the keyword table */
for (p = hashtab[hash(ident) % HASHMOD]; p != NULL; p = p->next) {
if (strequal(ident, p->text)) {
if (compress == YES && (c = p - keyword) < ' ') {
ident[0] = c; /* compress the keyword */
}
return(p->text);
}
}
/* this is an identifier */
return(NULL);
}
/* form hash value for string */
int
hash(char *ss)
{
int i;
unsigned char *s = (unsigned char *)ss;
for (i = 0; *s != '\0'; )
i += *s++; /* += is faster than <<= for cscope */
return(i);
}
?id=63dfef75ed75364901d7caa52c6420cec3e73519'>patch)
| tree | 8c3065d18a1b80da112ec1ee9a1074240cd100ca |
|---|
| parent | 29200c199cc9bde59033ab30fcc40b6c8ae630b0 (diff) |
|---|
bpf: enable verifier to add 0 to packet ptr
The patch fixes the case when adding a zero value to the packet
pointer. The zero value could come from src_reg equals type
BPF_K or CONST_IMM. The patch fixes both, otherwise the verifer
reports the following error:
[...]
R0=imm0,min_value=0,max_value=0
R1=pkt(id=0,off=0,r=4)
R2=pkt_end R3=fp-12
R4=imm4,min_value=4,max_value=4
R5=pkt(id=0,off=4,r=4)
269: (bf) r2 = r0 // r2 becomes imm0
270: (77) r2 >>= 3
271: (bf) r4 = r1 // r4 becomes pkt ptr
272: (0f) r4 += r2 // r4 += 0
addition of negative constant to packet pointer is not allowed
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: Mihai Budiu <mbudiu@vmware.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed, 24 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c |