@@ -3179,7 +3179,8 @@ static void load_elf_image(const char *image_name, const ImageSource *src,
char **pinterp_name)
{
g_autofree struct elf_phdr *phdr = NULL;
- abi_ulong load_addr, load_bias, loaddr, hiaddr, error;
+ abi_ulong load_addr, load_bias, loaddr, hiaddr, error, align;
+ size_t reserve_size, align_size;
int i, prot_exec;
Error *err = NULL;
@@ -3263,6 +3264,9 @@ static void load_elf_image(const char *image_name, const ImageSource *src,
load_addr = loaddr;
+ align = pow2ceil(info->alignment);
+ info->alignment = align;
+
if (pinterp_name != NULL) {
if (ehdr->e_type == ET_EXEC) {
/*
@@ -3271,8 +3275,6 @@ static void load_elf_image(const char *image_name, const ImageSource *src,
*/
probe_guest_base(image_name, loaddr, hiaddr);
} else {
- abi_ulong align;
-
/*
* The binary is dynamic, but we still need to
* select guest_base. In this case we pass a size.
@@ -3290,10 +3292,7 @@ static void load_elf_image(const char *image_name, const ImageSource *src,
* Since we do not have complete control over the guest
* address space, we prefer the kernel to choose some address
* rather than force the use of LOAD_ADDR via MAP_FIXED.
- * But without MAP_FIXED we cannot guarantee alignment,
- * only suggest it.
*/
- align = pow2ceil(info->alignment);
if (align) {
load_addr &= -align;
}
@@ -3317,13 +3316,35 @@ static void load_elf_image(const char *image_name, const ImageSource *src,
* In both cases, we will overwrite pages in this range with mappings
* from the executable.
*/
- load_addr = target_mmap(load_addr, (size_t)hiaddr - loaddr + 1, PROT_NONE,
+ reserve_size = (size_t)hiaddr - loaddr + 1;
+ align_size = reserve_size;
+
+ if (ehdr->e_type != ET_EXEC && align > qemu_real_host_page_size()) {
+ align_size += align - 1;
+ }
+
+ load_addr = target_mmap(load_addr, align_size, PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE |
(ehdr->e_type == ET_EXEC ? MAP_FIXED_NOREPLACE : 0),
-1, 0);
if (load_addr == -1) {
goto exit_mmap;
}
+
+ if (align_size != reserve_size) {
+ abi_ulong align_addr = ROUND_UP(load_addr, align);
+ abi_ulong align_end = align_addr + reserve_size;
+ abi_ulong load_end = load_addr + align_size;
+
+ if (align_addr != load_addr) {
+ target_munmap(load_addr, align_addr - load_addr);
+ }
+ if (align_end != load_end) {
+ target_munmap(align_end, load_end - align_end);
+ }
+ load_addr = align_addr;
+ }
+
load_bias = load_addr - loaddr;
if (elf_is_fdpic(ehdr)) {
Most binaries don't actually depend on more than page alignment, but any binary can request it. Not honoring this was a bug. This became obvious when gdb reported Failed to read a valid object file image from memory when examining some vdso which are marked as needing more than page alignment. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/elfload.c | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-)