mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 10:29:37 +00:00
6549a8c0c3
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by this
change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200515172926.GA31976@embeddedor
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
140 lines
2.9 KiB
C
140 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* jitdump.h: jitted code info encapsulation file format
|
|
*
|
|
* Adapted from OProfile GPLv2 support jidump.h:
|
|
* Copyright 2007 OProfile authors
|
|
* Jens Wilke
|
|
* Daniel Hansel
|
|
* Copyright IBM Corporation 2007
|
|
*/
|
|
#ifndef JITDUMP_H
|
|
#define JITDUMP_H
|
|
|
|
#include <sys/time.h>
|
|
#include <time.h>
|
|
#include <stdint.h>
|
|
|
|
/* JiTD */
|
|
#define JITHEADER_MAGIC 0x4A695444
|
|
#define JITHEADER_MAGIC_SW 0x4454694A
|
|
|
|
#define PADDING_8ALIGNED(x) ((((x) + 7) & 7) ^ 7)
|
|
#define ALIGN_8(x) (((x) + 7) & (~7))
|
|
|
|
#define JITHEADER_VERSION 1
|
|
|
|
enum jitdump_flags_bits {
|
|
JITDUMP_FLAGS_ARCH_TIMESTAMP_BIT,
|
|
JITDUMP_FLAGS_MAX_BIT,
|
|
};
|
|
|
|
#define JITDUMP_FLAGS_ARCH_TIMESTAMP (1ULL << JITDUMP_FLAGS_ARCH_TIMESTAMP_BIT)
|
|
|
|
#define JITDUMP_FLAGS_RESERVED (JITDUMP_FLAGS_MAX_BIT < 64 ? \
|
|
(~((1ULL << JITDUMP_FLAGS_MAX_BIT) - 1)) : 0)
|
|
|
|
struct jitheader {
|
|
uint32_t magic; /* characters "jItD" */
|
|
uint32_t version; /* header version */
|
|
uint32_t total_size; /* total size of header */
|
|
uint32_t elf_mach; /* elf mach target */
|
|
uint32_t pad1; /* reserved */
|
|
uint32_t pid; /* JIT process id */
|
|
uint64_t timestamp; /* timestamp */
|
|
uint64_t flags; /* flags */
|
|
};
|
|
|
|
enum jit_record_type {
|
|
JIT_CODE_LOAD = 0,
|
|
JIT_CODE_MOVE = 1,
|
|
JIT_CODE_DEBUG_INFO = 2,
|
|
JIT_CODE_CLOSE = 3,
|
|
JIT_CODE_UNWINDING_INFO = 4,
|
|
|
|
JIT_CODE_MAX,
|
|
};
|
|
|
|
/* record prefix (mandatory in each record) */
|
|
struct jr_prefix {
|
|
uint32_t id;
|
|
uint32_t total_size;
|
|
uint64_t timestamp;
|
|
};
|
|
|
|
struct jr_code_load {
|
|
struct jr_prefix p;
|
|
|
|
uint32_t pid;
|
|
uint32_t tid;
|
|
uint64_t vma;
|
|
uint64_t code_addr;
|
|
uint64_t code_size;
|
|
uint64_t code_index;
|
|
};
|
|
|
|
struct jr_code_close {
|
|
struct jr_prefix p;
|
|
};
|
|
|
|
struct jr_code_move {
|
|
struct jr_prefix p;
|
|
|
|
uint32_t pid;
|
|
uint32_t tid;
|
|
uint64_t vma;
|
|
uint64_t old_code_addr;
|
|
uint64_t new_code_addr;
|
|
uint64_t code_size;
|
|
uint64_t code_index;
|
|
};
|
|
|
|
struct debug_entry {
|
|
uint64_t addr;
|
|
int lineno; /* source line number starting at 1 */
|
|
int discrim; /* column discriminator, 0 is default */
|
|
const char name[]; /* null terminated filename, \xff\0 if same as previous entry */
|
|
};
|
|
|
|
struct jr_code_debug_info {
|
|
struct jr_prefix p;
|
|
|
|
uint64_t code_addr;
|
|
uint64_t nr_entry;
|
|
struct debug_entry entries[];
|
|
};
|
|
|
|
struct jr_code_unwinding_info {
|
|
struct jr_prefix p;
|
|
|
|
uint64_t unwinding_size;
|
|
uint64_t eh_frame_hdr_size;
|
|
uint64_t mapped_size;
|
|
const char unwinding_data[];
|
|
};
|
|
|
|
union jr_entry {
|
|
struct jr_code_debug_info info;
|
|
struct jr_code_close close;
|
|
struct jr_code_load load;
|
|
struct jr_code_move move;
|
|
struct jr_prefix prefix;
|
|
struct jr_code_unwinding_info unwinding;
|
|
};
|
|
|
|
static inline struct debug_entry *
|
|
debug_entry_next(struct debug_entry *ent)
|
|
{
|
|
void *a = ent + 1;
|
|
size_t l = strlen(ent->name) + 1;
|
|
return a + l;
|
|
}
|
|
|
|
static inline char *
|
|
debug_entry_file(struct debug_entry *ent)
|
|
{
|
|
void *a = ent + 1;
|
|
return a;
|
|
}
|
|
|
|
#endif /* !JITDUMP_H */
|