Hello Jingbai,
>This patch fixes a bug that will cause segment fault if the starting or ending
>address of the ELF segment is not aligned to 8 pages boundary.
>
>Changelog:
>v3:
>- Fix patch description error.
Thanks, applied for v1.5.6.
Atsushi Kumagai
>v2:
>- Change subject to describe patch correctly.
>- Some minor code format changes.
>
>In function create_1st_bitmap_cyclic() and initialize_2nd_bitmap_cyclic(),
>there are the same code:
>
> pfn_start_roundup = roundup(pfn_start, BITPERBYTE);
> pfn_end_round = round(pfn_end, BITPERBYTE);
>
> for (pfn = pfn_start; pfn < pfn_start_roundup; pfn++) {
> if (set_bit_on_1st_bitmap(pfn))
> pfn_bitmap1++;
> }
>
>In case:
>pfn_start=0xe762c, pfn_start_roundup=0xe7630
>pfn_end=0xe762d, pfn_end_round=0xe7628
>This code will set incorrect bits in the bitmap.
>In function readpage_elf():
>
> if (!offset1) {
> phys_start = page_head_to_phys_start(paddr);
> offset1 = paddr_to_offset(phys_start);
> frac_head = phys_start - paddr;
> memset(bufptr, 0, frac_head);
> }
>
>The invalid paddr couldn't be found, so phys_start will be zero, and frac_head
>will be negative, then memset will cause a segment fault.
>
>Signed-off-by: Jingbai Ma <jingbai.ma at hp.com>
>---
> makedumpfile.c | 27 +++++++++++++++++----------
> 1 files changed, 17 insertions(+), 10 deletions(-)
>
>diff --git a/makedumpfile.c b/makedumpfile.c
>index ef08d91..900d553 100644
>--- a/makedumpfile.c
>+++ b/makedumpfile.c
>@@ -4424,8 +4424,9 @@ create_1st_bitmap_cyclic()
> if (pfn_start >= pfn_end)
> continue;
>
>- pfn_start_roundup = roundup(pfn_start, BITPERBYTE);
>- pfn_end_round = round(pfn_end, BITPERBYTE);
>+ pfn_start_roundup = MIN(roundup(pfn_start, BITPERBYTE),
>+ pfn_end);
>+ pfn_end_round = MAX(round(pfn_end, BITPERBYTE), pfn_start);
>
> for (pfn = pfn_start; pfn < pfn_start_roundup; pfn++) {
> if (set_bit_on_1st_bitmap(pfn))
>@@ -4443,9 +4444,11 @@ create_1st_bitmap_cyclic()
> pfn_bitmap1 += (pfn_end_byte - pfn_start_byte) * BITPERBYTE;
> }
>
>- for (pfn = pfn_end_round; pfn < pfn_end; pfn++) {
>- if (set_bit_on_1st_bitmap(pfn))
>- pfn_bitmap1++;
>+ if (pfn_end_round > pfn_start) {
>+ for (pfn = pfn_end_round; pfn < pfn_end; pfn++) {
>+ if (set_bit_on_1st_bitmap(pfn))
>+ pfn_bitmap1++;
>+ }
> }
> }
> pfn_memhole -= pfn_bitmap1;
>@@ -4532,8 +4535,9 @@ initialize_2nd_bitmap_cyclic(void)
> if (pfn_start >= pfn_end)
> continue;
>
>- pfn_start_roundup = roundup(pfn_start, BITPERBYTE);
>- pfn_end_round = round(pfn_end, BITPERBYTE);
>+ pfn_start_roundup = MIN(roundup(pfn_start, BITPERBYTE),
>+ pfn_end);
>+ pfn_end_round = MAX(round(pfn_end, BITPERBYTE), pfn_start);
>
> for (pfn = pfn_start; pfn < pfn_start_roundup; ++pfn)
> if (!set_bit_on_2nd_bitmap_for_kernel(pfn))
>@@ -4548,9 +4552,12 @@ initialize_2nd_bitmap_cyclic(void)
> pfn_end_byte - pfn_start_byte);
> }
>
>- for (pfn = pfn_end_round; pfn < pfn_end; ++pfn)
>- if (!set_bit_on_2nd_bitmap_for_kernel(pfn))
>- return FALSE;
>+ if (pfn_end_round > pfn_start) {
>+ for (pfn = pfn_end_round; pfn < pfn_end; ++pfn) {
>+ if (!set_bit_on_2nd_bitmap_for_kernel(pfn))
>+ return FALSE;
>+ }
>+ }
> }
>
> return TRUE;
