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-rw-r--r--fs/binfmt_elf.c33
1 files changed, 23 insertions, 10 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index fa582748be41..f8c7f26f1fbb 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -156,7 +156,7 @@ static int padzero(unsigned long elf_bss)
#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
#define STACK_ROUND(sp, items) \
(((unsigned long) (sp - items)) &~ 15UL)
-#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
+#define STACK_ALLOC(sp, len) (sp -= len)
#endif
#ifndef ELF_BASE_PLATFORM
@@ -1074,20 +1074,26 @@ out_free_interp:
vaddr = elf_ppnt->p_vaddr;
/*
- * If we are loading ET_EXEC or we have already performed
- * the ET_DYN load_addr calculations, proceed normally.
+ * The first time through the loop, load_addr_set is false:
+ * layout will be calculated. Once set, use MAP_FIXED since
+ * we know we've already safely mapped the entire region with
+ * MAP_FIXED_NOREPLACE in the once-per-binary logic following.
*/
- if (elf_ex->e_type == ET_EXEC || load_addr_set) {
+ if (load_addr_set) {
elf_flags |= MAP_FIXED;
+ } else if (elf_ex->e_type == ET_EXEC) {
+ /*
+ * This logic is run once for the first LOAD Program
+ * Header for ET_EXEC binaries. No special handling
+ * is needed.
+ */
+ elf_flags |= MAP_FIXED_NOREPLACE;
} else if (elf_ex->e_type == ET_DYN) {
/*
* This logic is run once for the first LOAD Program
* Header for ET_DYN binaries to calculate the
* randomization (load_bias) for all the LOAD
- * Program Headers, and to calculate the entire
- * size of the ELF mapping (total_size). (Note that
- * load_addr_set is set to true later once the
- * initial mapping is performed.)
+ * Program Headers.
*
* There are effectively two types of ET_DYN
* binaries: programs (i.e. PIE: ET_DYN with INTERP)
@@ -1108,7 +1114,7 @@ out_free_interp:
* Therefore, programs are loaded offset from
* ELF_ET_DYN_BASE and loaders are loaded into the
* independently randomized mmap region (0 load_bias
- * without MAP_FIXED).
+ * without MAP_FIXED nor MAP_FIXED_NOREPLACE).
*/
if (interpreter) {
load_bias = ELF_ET_DYN_BASE;
@@ -1117,7 +1123,7 @@ out_free_interp:
alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
if (alignment)
load_bias &= ~(alignment - 1);
- elf_flags |= MAP_FIXED;
+ elf_flags |= MAP_FIXED_NOREPLACE;
} else
load_bias = 0;
@@ -1129,7 +1135,14 @@ out_free_interp:
* is then page aligned.
*/
load_bias = ELF_PAGESTART(load_bias - vaddr);
+ }
+ /*
+ * Calculate the entire size of the ELF mapping (total_size).
+ * (Note that load_addr_set is set to true later once the
+ * initial mapping is performed.)
+ */
+ if (!load_addr_set) {
total_size = total_mapping_size(elf_phdata,
elf_ex->e_phnum);
if (!total_size) {