!580 elf/ld.so: Consider maybe-existing hole between PT_LOAD segments when mmap reserved area

From: @lvying6 
Reviewed-by: @liqingqing_1229 
Signed-off-by: @liqingqing_1229

elf-ld.so-Consider-maybe-existing-hole-between-PT_LO.patch

@@ -0,0 +1,47 @@
+From 1b296563c92c896f072343b5f19286e8b5942b9e Mon Sep 17 00:00:00 2001
+From: hubin <hubin73@huawei.com>
+Date: Fri, 28 Apr 2023 11:30:47 +0800
+Subject: [PATCH] elf/ld.so: Consider maybe-existing hole between PT_LOAD
+ segments when mmap reserved area
+
+When mmap reserved area do NOT consider existing hole between PT_LOAD
+segments, this will cause reserved virtual address space too small to
+contain all the sections in the PT_LOAD segment. Since the address space
+mapping of subsequent segments is based on the reserved address space,
+each mmap has a MAP_FIXED flag, which will overwrite the reserved
+address space, if the reserved space is too small, these mmap with
+MAP_FIEXED flag will conflict with other address space. e.g. in some
+case, the address sapce in the .bss section(last data segment) conflicts
+with the address space in the heap(maybe other address space) cause the
+program coredump.
+---
+ elf/dl-map-segments-hugepage.h | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/elf/dl-map-segments-hugepage.h b/elf/dl-map-segments-hugepage.h
+index b99f726f..218e93a0 100644
+--- a/elf/dl-map-segments-hugepage.h
++++ b/elf/dl-map-segments-hugepage.h
+@@ -47,10 +47,18 @@ __mmap_reserved_area(const struct loadcmd loadcmds[], size_t nloadcmds,
+   const struct loadcmd * c = loadcmds;
+   *maparealen = 0;
+ 
++  /*
++   * Consider maybe-existing hole between PT_LOAD segments
++   */
+   while (c < &loadcmds[nloadcmds])
+     {
+-      *maparealen += ALIGN_UP((c->mapend > c->allocend ? c->mapend : c->allocend), SIZE_2MB) -
++      // c is not the last loadcmd
++      if (c + 1 < &loadcmds[nloadcmds]) {
++        *maparealen += ALIGN_UP((c + 1)->mapstart - c->mapstart, SIZE_2MB);
++      } else {
++        *maparealen += ALIGN_UP((c->mapend > c->allocend ? c->mapend : c->allocend), SIZE_2MB) -
+                       ALIGN_DOWN(c->mapstart, SIZE_2MB);
++      }
+       c++;
+     }
+ 
+-- 
+2.38.1
+

glibc.spec

@@ -66,7 +66,7 @@
 ##############################################################################
 Name: 	 	glibc
 Version: 	2.34
-Release: 	117
+Release: 	118
 Summary: 	The GNU libc libraries
 License:	%{all_license}
 URL: 		http://www.gnu.org/software/glibc/
@@ -297,6 +297,7 @@ Patch9034: 0002-elf-ld.so-keep-compatible-with-the-original-policy-o.patch
 Patch9035: 0003-elf-ld.so-remove-_mmap_hole-when-ld.so-mmap-PT_LOAD-.patch
 Patch9036: elf-ld.so-add-MAP_NORESERVE-flag-for-the-first-mmap-2MB-contig.patch
 Patch9037: elf-ld.so-prohibit-multiple-i-options-and-do-not-allow-i-speci.patch
+Patch9038: elf-ld.so-Consider-maybe-existing-hole-between-PT_LO.patch
 
 Provides: ldconfig rtld(GNU_HASH) bundled(gnulib)
 
@@ -1462,6 +1463,9 @@ fi
 %endif
 
 %changelog
+* Fri Apr 28 2023 Lv Ying <lvying6@huawei.com> - 2.34-118
+- malloc: elf/ld.so: Consider maybe-existing hole between PT_LOAD segments when mmap reserved area
+
 * Thu Apr 13 2023 Qingqing Li <liqingqing3@huawei.com> - 2.34-117
 - malloc: Fix -Wuse-after-free warning in tst-mallocalign1 [BZ #26779]