diff options
Diffstat (limited to 'main/musl/0069-work-around-incorrect-EPERM-from-mmap-syscall.patch')
| -rw-r--r-- | main/musl/0069-work-around-incorrect-EPERM-from-mmap-syscall.patch | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/main/musl/0069-work-around-incorrect-EPERM-from-mmap-syscall.patch b/main/musl/0069-work-around-incorrect-EPERM-from-mmap-syscall.patch new file mode 100644 index 0000000000..076f39c5ae --- /dev/null +++ b/main/musl/0069-work-around-incorrect-EPERM-from-mmap-syscall.patch @@ -0,0 +1,51 @@ +From da438ee1fc516c41ba1790cef7be551a9e244397 Mon Sep 17 00:00:00 2001 +From: Rich Felker <dalias@aerifal.cx> +Date: Wed, 6 Sep 2017 22:09:28 -0400 +Subject: [PATCH 27/30] work around incorrect EPERM from mmap syscall + +under some conditions, the mmap syscall wrongly fails with EPERM +instead of ENOMEM when memory is exhausted; this is probably the +result of the kernel trying to fit the allocation somewhere that +crosses into the kernel range or below mmap_min_addr. in any case it's +a conformance bug, so work around it. for now, only handle the case of +anonymous mappings with no requested address; in other cases EPERM may +be a legitimate error. + +this indirectly fixes the possibility of malloc failing with the wrong +errno value. +--- + src/mman/mmap.c | 9 +++++++-- + 1 file changed, 7 insertions(+), 2 deletions(-) + +diff --git a/src/mman/mmap.c b/src/mman/mmap.c +index 19caadbd..15924033 100644 +--- a/src/mman/mmap.c ++++ b/src/mman/mmap.c +@@ -14,6 +14,7 @@ weak_alias(dummy, __vm_wait); + + void *__mmap(void *start, size_t len, int prot, int flags, int fd, off_t off) + { ++ long ret; + if (off & OFF_MASK) { + errno = EINVAL; + return MAP_FAILED; +@@ -26,10 +27,14 @@ void *__mmap(void *start, size_t len, int prot, int flags, int fd, off_t off) + __vm_wait(); + } + #ifdef SYS_mmap2 +- return (void *)syscall(SYS_mmap2, start, len, prot, flags, fd, off/UNIT); ++ ret = __syscall(SYS_mmap2, start, len, prot, flags, fd, off/UNIT); + #else +- return (void *)syscall(SYS_mmap, start, len, prot, flags, fd, off); ++ ret = __syscall(SYS_mmap, start, len, prot, flags, fd, off); + #endif ++ /* Fixup incorrect EPERM from kernel. */ ++ if (ret == -EPERM && !start && (flags&MAP_ANON) && !(flags&MAP_FIXED)) ++ ret = -ENOMEM; ++ return (void *)__syscall_ret(ret); + } + + weak_alias(__mmap, mmap); +-- +2.13.3 + |