aboutsummaryrefslogtreecommitdiff
path: root/linux-user
diff options
context:
space:
mode:
authorRichard Henderson <richard.henderson@linaro.org>2023-08-02 15:58:07 -0700
committerRichard Henderson <richard.henderson@linaro.org>2023-08-08 13:27:17 -0700
commit1ea06ded0de5adcd40a0122ea73c9761f488bfba (patch)
treee21366bd68ef8fe9fd45ae03b177462890312077 /linux-user
parentad25051bae392ce35437cdf996aedecc0772af2f (diff)
downloadqemu-1ea06ded0de5adcd40a0122ea73c9761f488bfba.zip
qemu-1ea06ded0de5adcd40a0122ea73c9761f488bfba.tar.gz
qemu-1ea06ded0de5adcd40a0122ea73c9761f488bfba.tar.bz2
linux-user: Use elf_et_dyn_base for ET_DYN with interpreter
Follow the lead of the linux kernel in fs/binfmt_elf.c, in which an ET_DYN executable which uses an interpreter (usually a PIE executable) is loaded away from where the interpreter itself will be loaded. Tested-by: Helge Deller <deller@gmx.de> Reviewed-by: Helge Deller <deller@gmx.de> Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/elfload.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 1b4bb2d..d1b278d 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -3107,6 +3107,8 @@ static void load_elf_image(const char *image_name, int image_fd,
}
}
+ load_addr = loaddr;
+
if (pinterp_name != NULL) {
/*
* This is the main executable.
@@ -3136,11 +3138,32 @@ static void load_elf_image(const char *image_name, int image_fd,
*/
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.
*/
probe_guest_base(image_name, 0, hiaddr - loaddr);
+
+ /*
+ * Avoid collision with the loader by providing a different
+ * default load address.
+ */
+ load_addr += elf_et_dyn_base;
+
+ /*
+ * TODO: Better support for mmap alignment is desirable.
+ * 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;
+ }
}
}
@@ -3155,13 +3178,13 @@ static void load_elf_image(const char *image_name, int image_fd,
*
* Otherwise this is ET_DYN, and we are searching for a location
* that can hold the memory space required. If the image is
- * pre-linked, LOADDR will be non-zero, and the kernel should
+ * pre-linked, LOAD_ADDR will be non-zero, and the kernel should
* honor that address if it happens to be free.
*
* In both cases, we will overwrite pages in this range with mappings
* from the executable.
*/
- load_addr = target_mmap(loaddr, (size_t)hiaddr - loaddr + 1, PROT_NONE,
+ load_addr = target_mmap(load_addr, (size_t)hiaddr - loaddr + 1, PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE |
(ehdr->e_type == ET_EXEC ? MAP_FIXED_NOREPLACE : 0),
-1, 0);