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Index: sys/kern/link_elf.c
===================================================================
--- sys/kern/link_elf.c
+++ sys/kern/link_elf.c
@@ -736,9 +736,46 @@
#endif
#undef LS_PADDING
+/*
+ * Apply the specified protection to the loadable segments of a preloaded linker
+ * file.
+ */
static int
-link_elf_link_preload(linker_class_t cls,
- const char* filename, linker_file_t *result)
+preload_protect(elf_file_t ef, vm_prot_t prot)
+{
+#ifdef __amd64__
+ Elf_Ehdr *hdr;
+ Elf_Phdr *phdr, *phlimit;
+ vm_prot_t nprot;
+ int error;
+
+ error = 0;
+ hdr = (Elf_Ehdr *)ef->address;
+ phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff);
+ phlimit = phdr + hdr->e_phnum;
+ for (; phdr < phlimit; phdr++) {
+ if (phdr->p_type != PT_LOAD)
+ continue;
+
+ nprot = prot | VM_PROT_READ;
+ if ((phdr->p_flags & PF_W) != 0)
+ nprot |= VM_PROT_WRITE;
+ if ((phdr->p_flags & PF_X) != 0)
+ nprot |= VM_PROT_EXECUTE;
+ error = pmap_change_prot((vm_offset_t)ef->address +
+ phdr->p_vaddr, round_page(phdr->p_memsz), nprot);
+ if (error != 0)
+ break;
+ }
+ return (error);
+#else
+ return (0);
+#endif
+}
+
+static int
+link_elf_link_preload(linker_class_t cls, const char *filename,
+ linker_file_t *result)
{
Elf_Addr *ctors_addrp;
Elf_Size *ctors_sizep;
@@ -798,6 +835,8 @@
if (error == 0)
error = parse_vnet(ef);
#endif
+ if (error == 0)
+ error = preload_protect(ef, VM_PROT_ALL);
if (error != 0) {
linker_file_unload(lf, LINKER_UNLOAD_FORCE);
return (error);
@@ -815,6 +854,8 @@
ef = (elf_file_t) lf;
error = relocate_file(ef);
+ if (error == 0)
+ error = preload_protect(ef, VM_PROT_NONE);
if (error != 0)
return (error);
(void)link_elf_preload_parse_symbols(ef);
@@ -1274,6 +1315,7 @@
static void
link_elf_unload_preload(linker_file_t file)
{
+
if (file->pathname != NULL)
preload_delete_name(file->pathname);
}
Index: sys/vm/vm_kern.c
===================================================================
--- sys/vm/vm_kern.c
+++ sys/vm/vm_kern.c
@@ -834,6 +834,14 @@
end = trunc_page(start + size);
start = round_page(start);
+#ifdef __amd64__
+ /*
+ * Preloaded files do not have execute permissions by default on amd64.
+ * Restore the default permissions to ensure that the direct map alias
+ * is updated.
+ */
+ pmap_change_prot(start, end - start, VM_PROT_RW);
+#endif
for (va = start; va < end; va += PAGE_SIZE) {
pa = pmap_kextract(va);
m = PHYS_TO_VM_PAGE(pa);

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