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Index: head/libexec/rtld-elf/map_object.c
===================================================================
--- head/libexec/rtld-elf/map_object.c
+++ head/libexec/rtld-elf/map_object.c
@@ -40,11 +40,19 @@
#include "debug.h"
#include "rtld.h"
-static Elf_Ehdr *get_elf_header(int, const char *, const struct stat *);
+static Elf_Ehdr *get_elf_header(int, const char *, const struct stat *,
+ Elf_Phdr **phdr);
static int convert_flags(int); /* Elf flags -> mmap flags */
int __getosreldate(void);
+static bool
+phdr_in_zero_page(const Elf_Ehdr *hdr)
+{
+ return (hdr->e_phoff + hdr->e_phnum * sizeof(Elf_Phdr) <
+ (size_t)PAGE_SIZE);
+}
+
/*
* Map a shared object into memory. The "fd" argument is a file descriptor,
* which must be open on the object and positioned at its beginning.
@@ -95,17 +103,15 @@
size_t note_map_len;
Elf_Addr text_end;
- hdr = get_elf_header(fd, path, sb);
+ hdr = get_elf_header(fd, path, sb, &phdr);
if (hdr == NULL)
return (NULL);
/*
* Scan the program header entries, and save key information.
- *
* We expect that the loadable segments are ordered by load address.
*/
- phdr = (Elf_Phdr *)((char *)hdr + hdr->e_phoff);
- phsize = hdr->e_phnum * sizeof (phdr[0]);
+ phsize = hdr->e_phnum * sizeof(phdr[0]);
phlimit = phdr + hdr->e_phnum;
nsegs = -1;
phdyn = phinterp = phtls = NULL;
@@ -332,14 +338,18 @@
error:
if (note_map != NULL && note_map != MAP_FAILED)
munmap(note_map, note_map_len);
+ if (!phdr_in_zero_page(hdr))
+ munmap(phdr, hdr->e_phnum * sizeof(phdr[0]));
munmap(hdr, PAGE_SIZE);
return (NULL);
}
static Elf_Ehdr *
-get_elf_header(int fd, const char *path, const struct stat *sbp)
+get_elf_header(int fd, const char *path, const struct stat *sbp,
+ Elf_Phdr **phdr_p)
{
Elf_Ehdr *hdr;
+ Elf_Phdr *phdr;
/* Make sure file has enough data for the ELF header */
if (sbp != NULL && sbp->st_size < (off_t)sizeof(Elf_Ehdr)) {
@@ -388,11 +398,19 @@
"%s: invalid shared object: e_phentsize != sizeof(Elf_Phdr)", path);
goto error;
}
- if (hdr->e_phoff + hdr->e_phnum * sizeof(Elf_Phdr) >
- (size_t)PAGE_SIZE) {
- _rtld_error("%s: program header too large", path);
- goto error;
+ if (phdr_in_zero_page(hdr)) {
+ phdr = (Elf_Phdr *)((char *)hdr + hdr->e_phoff);
+ } else {
+ phdr = mmap(NULL, hdr->e_phnum * sizeof(phdr[0]),
+ PROT_READ, MAP_PRIVATE | MAP_PREFAULT_READ, fd,
+ hdr->e_phoff);
+ if (phdr == MAP_FAILED) {
+ _rtld_error("%s: error mapping phdr: %s", path,
+ rtld_strerror(errno));
+ goto error;
+ }
}
+ *phdr_p = phdr;
return (hdr);
error:

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