linux/lib/zlib_dfltcc/dfltcc_util.h
Ilya Leoshkevich 89f42df66c lib/zlib: unpoison DFLTCC output buffers
The constraints of the DFLTCC inline assembly are not precise: they do not
communicate the size of the output buffers to the compiler, so it cannot
automatically instrument it.

Add the manual kmsan_unpoison_memory() calls for the output buffers.  The
logic is the same as in [1].

[1] 1f5ddcc009

Link: https://lkml.kernel.org/r/20240621113706.315500-21-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:23 -07:00

131 lines
3.1 KiB
C

// SPDX-License-Identifier: Zlib
#ifndef DFLTCC_UTIL_H
#define DFLTCC_UTIL_H
#include "dfltcc.h"
#include <linux/kmsan-checks.h>
#include <linux/zutil.h>
/*
* C wrapper for the DEFLATE CONVERSION CALL instruction.
*/
typedef enum {
DFLTCC_CC_OK = 0,
DFLTCC_CC_OP1_TOO_SHORT = 1,
DFLTCC_CC_OP2_TOO_SHORT = 2,
DFLTCC_CC_OP2_CORRUPT = 2,
DFLTCC_CC_AGAIN = 3,
} dfltcc_cc;
#define DFLTCC_QAF 0
#define DFLTCC_GDHT 1
#define DFLTCC_CMPR 2
#define DFLTCC_XPND 4
#define HBT_CIRCULAR (1 << 7)
#define DFLTCC_FN_MASK ((1 << 7) - 1)
#define HB_BITS 15
#define HB_SIZE (1 << HB_BITS)
static inline dfltcc_cc dfltcc(
int fn,
void *param,
Byte **op1,
size_t *len1,
const Byte **op2,
size_t *len2,
void *hist
)
{
Byte *t2 = op1 ? *op1 : NULL;
unsigned char *orig_t2 = t2;
size_t t3 = len1 ? *len1 : 0;
const Byte *t4 = op2 ? *op2 : NULL;
size_t t5 = len2 ? *len2 : 0;
register int r0 __asm__("r0") = fn;
register void *r1 __asm__("r1") = param;
register Byte *r2 __asm__("r2") = t2;
register size_t r3 __asm__("r3") = t3;
register const Byte *r4 __asm__("r4") = t4;
register size_t r5 __asm__("r5") = t5;
int cc;
__asm__ volatile(
".insn rrf,0xb9390000,%[r2],%[r4],%[hist],0\n"
"ipm %[cc]\n"
: [r2] "+r" (r2)
, [r3] "+r" (r3)
, [r4] "+r" (r4)
, [r5] "+r" (r5)
, [cc] "=r" (cc)
: [r0] "r" (r0)
, [r1] "r" (r1)
, [hist] "r" (hist)
: "cc", "memory");
t2 = r2; t3 = r3; t4 = r4; t5 = r5;
/*
* Unpoison the parameter block and the output buffer.
* This is a no-op in non-KMSAN builds.
*/
switch (fn & DFLTCC_FN_MASK) {
case DFLTCC_QAF:
kmsan_unpoison_memory(param, sizeof(struct dfltcc_qaf_param));
break;
case DFLTCC_GDHT:
kmsan_unpoison_memory(param, offsetof(struct dfltcc_param_v0, csb));
break;
case DFLTCC_CMPR:
kmsan_unpoison_memory(param, sizeof(struct dfltcc_param_v0));
kmsan_unpoison_memory(
orig_t2,
t2 - orig_t2 +
(((struct dfltcc_param_v0 *)param)->sbb == 0 ? 0 : 1));
break;
case DFLTCC_XPND:
kmsan_unpoison_memory(param, sizeof(struct dfltcc_param_v0));
kmsan_unpoison_memory(orig_t2, t2 - orig_t2);
break;
}
if (op1)
*op1 = t2;
if (len1)
*len1 = t3;
if (op2)
*op2 = t4;
if (len2)
*len2 = t5;
return (cc >> 28) & 3;
}
static inline int is_bit_set(
const char *bits,
int n
)
{
return bits[n / 8] & (1 << (7 - (n % 8)));
}
static inline void turn_bit_off(
char *bits,
int n
)
{
bits[n / 8] &= ~(1 << (7 - (n % 8)));
}
static inline int dfltcc_are_params_ok(
int level,
uInt window_bits,
int strategy,
uLong level_mask
)
{
return (level_mask & (1 << level)) != 0 &&
(window_bits == HB_BITS) &&
(strategy == Z_DEFAULT_STRATEGY);
}
char *oesc_msg(char *buf, int oesc);
#endif /* DFLTCC_UTIL_H */