openkylin
/
qemu
mirror of https://gitee.com/openkylin/qemu.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

dump: eliminate DumpState.page_size ("guest's page size") 

Use TARGET_PAGE_SIZE and ~TARGET_PAGE_MASK instead.

"DumpState.page_size" has type "size_t", whereas TARGET_PAGE_SIZE has type
"int". TARGET_PAGE_MASK is of type "int" and has negative value. The patch
affects the implicit type conversions as follows:

- create_header32() and create_header64(): assigned to "block_size", which
  has type "uint32_t". No change.

- get_next_page(): "block->target_start", "block->target_end" and "addr"
  have type "hwaddr" (uint64_t).

  Before the patch,
  - if "size_t" was "uint64_t", then no additional conversion was done as
    part of the usual arithmetic conversions,
  - If "size_t" was "uint32_t", then it was widened to uint64_t as part of
    the usual arithmetic conversions,
  for the remainder and addition operators.

  After the patch,
  - "~TARGET_PAGE_MASK" expands to  ~~((1 << TARGET_PAGE_BITS) - 1). It
    has type "int" and positive value (only least significant bits set).
    That's converted (widened) to "uint64_t" for the bit-ands. No visible
    change.
  - The same holds for the (addr + TARGET_PAGE_SIZE) addition.

- write_dump_pages():
  - TARGET_PAGE_SIZE passed as argument to a bunch of functions that all
    have prototypes. No change.

  - When incrementing "offset_data" (of type "off_t"): given that we never
    build for ILP32_OFF32 (see "-D_FILE_OFFSET_BITS=64" in configure),
    "off_t" is always "int64_t", and we only need to consider:
    - ILP32_OFFBIG: "size_t" is "uint32_t".
      - before: int64_t += uint32_t. Page size converted to int64_t for
        the addition.
      - after:  int64_t += int32_t. No change.
    - LP64_OFF64: "size_t" is "uint64_t".
      - before: int64_t += uint64_t. Offset converted to uint64_t for the
        addition, then the uint64_t result is converted to int64_t for
        storage.
      - after:  int64_t += int32_t. Same as the ILP32_OFFBIG/after case.
        No visible change.

  - (size_out < s->page_size) comparisons, and (size_out = s->page_size)
    assignment:
    - before: "size_out" is of type "size_t", no implicit conversion for
              either operator.
    - after: TARGET_PAGE_SIZE (of type "int" and positive value) is
             converted to "size_t" (for the relop because the latter is
             one of "uint32_t" and "uint64_t"). No visible change.

- dump_init():
  - DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), s->page_size): The
    innermost "DumpState.max_mapnr" field has type uint64_t, which
    propagates through all implicit conversions at hand:

    #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

    regardless of the page size macro argument's type. In the outer macro
    replacement, the page size is converted from uint32_t and int32_t
    alike to uint64_t.

  - (tmp * s->page_size) multiplication: "tmp" has size "uint64_t"; the
    RHS is converted to that type from uint32_t and int32_t just the same
    if it's not uint64_t to begin with.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
This commit is contained in:
Laszlo Ersek 2014-05-20 13:39:44 +02:00 committed by Luiz Capitulino
parent 22227f121b
commit 2f859f80c2
1 changed files with 25 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
dump.c
View File

@ -90,7 +90,6 @@ typedef struct DumpState {
uint8_t *note_buf; /* buffer for notes */
size_t note_buf_offset; /* the writing place in note_buf */
uint32_t nr_cpus; /* number of guest's cpu */
size_t page_size; /* guest's page size */
uint64_t max_mapnr; /* the biggest guest's phys-mem's number */
size_t len_dump_bitmap; /* the size of the place used to store
dump_bitmap in vmcore */
@ -805,7 +804,7 @@ static int create_header32(DumpState *s)
strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
dh->header_version = cpu_convert_to_target32(6, endian);
block_size = s->page_size;
block_size = TARGET_PAGE_SIZE;
dh->block_size = cpu_convert_to_target32(block_size, endian);
sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
@ -912,7 +911,7 @@ static int create_header64(DumpState *s)
strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
dh->header_version = cpu_convert_to_target32(6, endian);
block_size = s->page_size;
block_size = TARGET_PAGE_SIZE;
dh->block_size = cpu_convert_to_target32(block_size, endian);
sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
@ -1083,8 +1082,8 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
if (!block) {
block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
*blockptr = block;
assert(block->target_start % s->page_size == 0);
assert(block->target_end % s->page_size == 0);
assert((block->target_start & ~TARGET_PAGE_MASK) == 0);
assert((block->target_end & ~TARGET_PAGE_MASK) == 0);
*pfnptr = paddr_to_pfn(block->target_start);
if (bufptr) {
*bufptr = block->host_addr;
@ -1096,7 +1095,7 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
addr = pfn_to_paddr(*pfnptr);
if ((addr >= block->target_start) &&
(addr + s->page_size <= block->target_end)) {
(addr + TARGET_PAGE_SIZE <= block->target_end)) {
buf = block->host_addr + (addr - block->target_start);
} else {
/* the next page is in the next block */
@ -1105,8 +1104,8 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
if (!block) {
return false;
}
assert(block->target_start % s->page_size == 0);
assert(block->target_end % s->page_size == 0);
assert((block->target_start & ~TARGET_PAGE_MASK) == 0);
assert((block->target_end & ~TARGET_PAGE_MASK) == 0);
*pfnptr = paddr_to_pfn(block->target_start);
buf = block->host_addr;
}
@ -1291,7 +1290,7 @@ static int write_dump_pages(DumpState *s)
prepare_data_cache(&page_data, s, offset_data);
/* prepare buffer to store compressed data */
len_buf_out = get_len_buf_out(s->page_size, s->flag_compress);
len_buf_out = get_len_buf_out(TARGET_PAGE_SIZE, s->flag_compress);
if (len_buf_out == 0) {
dump_error(s, "dump: failed to get length of output buffer.\n");
goto out;
@ -1307,19 +1306,19 @@ static int write_dump_pages(DumpState *s)
* init zero page's page_desc and page_data, because every zero page
* uses the same page_data
*/
pd_zero.size = cpu_convert_to_target32(s->page_size, endian);
pd_zero.size = cpu_convert_to_target32(TARGET_PAGE_SIZE, endian);
pd_zero.flags = cpu_convert_to_target32(0, endian);
pd_zero.offset = cpu_convert_to_target64(offset_data, endian);
pd_zero.page_flags = cpu_convert_to_target64(0, endian);
buf = g_malloc0(s->page_size);
ret = write_cache(&page_data, buf, s->page_size, false);
buf = g_malloc0(TARGET_PAGE_SIZE);
ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
g_free(buf);
if (ret < 0) {
dump_error(s, "dump: failed to write page data(zero page).\n");
goto out;
}
offset_data += s->page_size;
offset_data += TARGET_PAGE_SIZE;
/*
* dump memory to vmcore page by page. zero page will all be resided in the
@ -1327,7 +1326,7 @@ static int write_dump_pages(DumpState *s)
*/
while (get_next_page(&block_iter, &pfn_iter, &buf, s)) {
/* check zero page */
if (is_zero_page(buf, s->page_size)) {
if (is_zero_page(buf, TARGET_PAGE_SIZE)) {
ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
false);
if (ret < 0) {
@ -1348,8 +1347,9 @@ static int write_dump_pages(DumpState *s)
*/
size_out = len_buf_out;
if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
(compress2(buf_out, (uLongf *)&size_out, buf, s->page_size,
Z_BEST_SPEED) == Z_OK) && (size_out < s->page_size)) {
(compress2(buf_out, (uLongf *)&size_out, buf,
TARGET_PAGE_SIZE, Z_BEST_SPEED) == Z_OK) &&
(size_out < TARGET_PAGE_SIZE)) {
pd.flags = cpu_convert_to_target32(DUMP_DH_COMPRESSED_ZLIB,
endian);
pd.size = cpu_convert_to_target32(size_out, endian);
@ -1361,9 +1361,9 @@ static int write_dump_pages(DumpState *s)
}
#ifdef CONFIG_LZO
} else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
(lzo1x_1_compress(buf, s->page_size, buf_out,
(lzo1x_1_compress(buf, TARGET_PAGE_SIZE, buf_out,
(lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
(size_out < s->page_size)) {
(size_out < TARGET_PAGE_SIZE)) {
pd.flags = cpu_convert_to_target32(DUMP_DH_COMPRESSED_LZO,
endian);
pd.size = cpu_convert_to_target32(size_out, endian);
@ -1376,9 +1376,9 @@ static int write_dump_pages(DumpState *s)
#endif
#ifdef CONFIG_SNAPPY
} else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
(snappy_compress((char *)buf, s->page_size,
(snappy_compress((char *)buf, TARGET_PAGE_SIZE,
(char *)buf_out, &size_out) == SNAPPY_OK) &&
(size_out < s->page_size)) {
(size_out < TARGET_PAGE_SIZE)) {
pd.flags = cpu_convert_to_target32(
DUMP_DH_COMPRESSED_SNAPPY, endian);
pd.size = cpu_convert_to_target32(size_out, endian);
@ -1392,13 +1392,13 @@ static int write_dump_pages(DumpState *s)
} else {
/*
* fall back to save in plaintext, size_out should be
* assigned to s->page_size
* assigned TARGET_PAGE_SIZE
*/
pd.flags = cpu_convert_to_target32(0, endian);
size_out = s->page_size;
size_out = TARGET_PAGE_SIZE;
pd.size = cpu_convert_to_target32(size_out, endian);
ret = write_cache(&page_data, buf, s->page_size, false);
ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
if (ret < 0) {
dump_error(s, "dump: failed to write page data.\n");
goto out;
@ -1610,13 +1610,12 @@ static int dump_init(DumpState *s, int fd, bool has_format,
}
s->nr_cpus = nr_cpus;
s->page_size = TARGET_PAGE_SIZE;
get_max_mapnr(s);
uint64_t tmp;
tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), s->page_size);
s->len_dump_bitmap = tmp * s->page_size;
tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), TARGET_PAGE_SIZE);
s->len_dump_bitmap = tmp * TARGET_PAGE_SIZE;
/* init for kdump-compressed format */
if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {