git: 00df149452bf - stable/13 - crt_malloc: more accurate handling of mmap(2) failure

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Sat, 23 Oct 2021 01:12:28 UTC
The branch stable/13 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=00df149452bfd1b9eee9acba842bb6bc874c5ae3

commit 00df149452bfd1b9eee9acba842bb6bc874c5ae3
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2021-10-15 17:59:37 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2021-10-22 23:32:27 +0000

    crt_malloc: more accurate handling of mmap(2) failure
    
    PR:     259076
    
    (cherry picked from commit 73dddffc3175581ba99f6ced9a2e508a0e880e59)
---
 libexec/rtld-elf/rtld_malloc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/libexec/rtld-elf/rtld_malloc.c b/libexec/rtld-elf/rtld_malloc.c
index 64218b5bb786..63fa6f5e2ee7 100644
--- a/libexec/rtld-elf/rtld_malloc.c
+++ b/libexec/rtld-elf/rtld_malloc.c
@@ -271,21 +271,21 @@ morepages(int n)
 		}
 	}
 
-	if (pagepool_start == MAP_FAILED)
-		pagepool_start = 0;
 	offset = (uintptr_t)pagepool_start - rounddown2(
 	    (uintptr_t)pagepool_start, pagesz);
 
-	pagepool_start = mmap(0, n * pagesz, PROT_READ | PROT_WRITE,
+	addr = mmap(0, n * pagesz, PROT_READ | PROT_WRITE,
 	    MAP_ANON | MAP_PRIVATE, -1, 0);
-	if (pagepool_start == MAP_FAILED) {
+	if (addr == MAP_FAILED) {
 #ifdef IN_RTLD
 		rtld_fdprintf(STDERR_FILENO, _BASENAME_RTLD ": morepages: "
 		    "cannot mmap anonymous memory: %s\n",
 		    rtld_strerror(errno));
 #endif
+		pagepool_start = pagepool_end = NULL;
 		return (0);
 	}
+	pagepool_start = addr;
 	pagepool_end = pagepool_start + n * pagesz;
 	pagepool_start += offset;