On Wed, 15 May 2013 13:43:59 -0500
Cliff Wickman <cpw at sgi.com> wrote:
> From: Cliff Wickman <cpw at sgi.com>
>
> If the crash kernel does not support mmap(2) of /proc/vmcore, make
> makedumpfile fall back to using reads with a non-alarming message.
>
> Signed-off-by: Cliff Wickman <cpw at sgi.com>
> ---
> makedumpfile.c | 37 ++++++++++++++++++++++---------------
> 1 file changed, 22 insertions(+), 15 deletions(-)
>
> Index: makedumpfile.mmap/makedumpfile.c
> ===================================================================
> --- makedumpfile.mmap.orig/makedumpfile.c
> +++ makedumpfile.mmap/makedumpfile.c
> @@ -239,7 +239,7 @@ read_page_desc(unsigned long long paddr,
> }
>
> static int
> -update_mmap_range(off_t offset) {
> +update_mmap_range(off_t offset, int initial) {
> off_t start_offset;
> off_t map_size;
> off_t max_offset = get_max_file_offset();
> @@ -258,10 +258,11 @@ update_mmap_range(off_t offset) {
> info->fd_memory, start_offset);
>
> if (info->mmap_buf == MAP_FAILED) {
> - ERRMSG("Can't map [%llx-%llx] with mmap()\n %s",
> - (ulonglong)start_offset,
> - (ulonglong)(start_offset + map_size),
> - strerror(errno));
> + if (!initial)
> + ERRMSG("Can't map [%llx-%llx] with mmap()\n %s",
> + (ulonglong)start_offset,
> + (ulonglong)(start_offset + map_size),
> + strerror(errno));
> return FALSE;
> }
>
> @@ -285,7 +286,7 @@ is_mapped_with_mmap(off_t offset) {
> int
> initialize_mmap(void) {
> info->mmap_buf = MAP_FAILED;
> - if (!update_mmap_range(0))
> + if (!update_mmap_range(0, 1))
> return FALSE;
>
> return TRUE;
> @@ -298,7 +299,7 @@ read_with_mmap(off_t offset, void *bufpt
> next_region:
>
> if (!is_mapped_with_mmap(offset)) {
> - if (!update_mmap_range(offset))
> + if (!update_mmap_range(offset, 0))
> return FALSE;
> }
Where came from this original code ?
The current code in mmap branch doesn't look the return value of
update_mmap_range():
if (!is_mapped_with_mmap(offset))
update_mmap_range(offset);
Anyway, I'll merge this patch into mmap branch after I push the patch
below.
Thanks
Atsushi Kumagai
-----------------------------------------------------------------------
Author: Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp>
Date: Thu May 17 15:02:19 2013 +0900
[PATCH] Add error handling for read_with_mmap().
Add error handling for read_with_mmap the same as read()'s case.
Signed-off-by: Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp>
diff --git a/makedumpfile.c b/makedumpfile.c
index fce2e35..1f656e8 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -291,7 +291,8 @@ read_with_mmap(off_t offset, void *bufptr, unsigned long size) {
next_region:
if (!is_mapped_with_mmap(offset))
- update_mmap_range(offset);
+ if (!update_mmap_range(offset))
+ return FALSE;
read_size = MIN(info->mmap_end_offset - offset, size);
@@ -320,9 +321,13 @@ readpage_elf(unsigned long long paddr, void *bufptr)
return FALSE;
}
- if (info->flag_usemmap)
- read_with_mmap(offset, bufptr, info->page_size);
- else {
+ if (info->flag_usemmap) {
+ if (!read_with_mmap(offset, bufptr, info->page_size)) {
+ ERRMSG("Can't read the dump memory(%s) with mmap().\n",
+ info->name_memory);
+ return FALSE;
+ }
+ } else {
if (lseek(info->fd_memory, offset, SEEK_SET) == failed) {
ERRMSG("Can't seek the dump memory(%s). (offset: %llx) %s\n",
info->name_memory, (unsigned long long)offset, strerror(errno));
> @@ -2984,14 +2985,20 @@ out:
> if (info->dump_level & DL_EXCLUDE_FREE)
> setup_page_is_buddy();
>
> - if (info->mmap_region_size > 0 && initialize_mmap()) {
> - /*
> - * The map size is specified as Kbyte with
> - * --map-size <size> option.
> - */
> - info->mmap_region_size <<= 10;
> - info->flag_usemmap = TRUE;
> - DEBUG_MSG("read %s with mmap()\n", info->name_memory);
> + if (info->mmap_region_size > 0) {
> + if (!initialize_mmap()) {
> + /* this kernel does not support mmap of vmcore */
> + ERRMSG("Kernel can't mmap vmcore, using reads.\n");
> + info->flag_usemmap = FALSE;
> + } else {
> + /*
> + * The map size is specified as Kbyte with
> + * --map-size <size> option.
> + */
> + info->mmap_region_size <<= 10;
> + info->flag_usemmap = TRUE;
> + DEBUG_MSG("read %s with mmap()\n", info->name_memory);
> + }
> } else {
> info->flag_usemmap = FALSE;
> DEBUG_MSG("read %s with read()\n", info->name_memory);
>
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