From 78f91e08c8a7b0f0c831a087f7c89e2c76047e7a Mon Sep 17 00:00:00 2001 From: Laurentiu Palcu Date: Fri, 5 Apr 2013 19:12:26 +0300 Subject: postinst-intercepts, qemu.bbclass: fix issue on 32 bit hosts The intercept scripts fail to run on 32 bit hosts. Apparently, the current approach worked on 64 bit hosts due to the larger virtual address space (probably). On 32 bit hosts, however, calling the target binary like: qemu-arm ld-linux.so --library-path /lib:/usr/lib arm_binary fails with: arm_binary: error while loading shared libraries: arm_binary: failed to map segment from shared object: Operation not permitted When run like this, qemu-arm fails to map the arm_binary executable in memory because it's hitting the lower limit of /proc/sys/vm/mmap_min_addr. That's because it loads the ld-linux.so binary successfully, taking into account mmap_min_addr, runs it, and then ld-linux.so will map the arm_binary at a fixed address but this will fail because it is below mmap_min_addr. The qemu's guest base probing, apparently, doesn't work fine when a program runs inside other. One way around this would be to set mmap_min_addr to 0 (on recent distributions is set to 65536 to avoid "kernel NULL pointer dereference" defects) but this approach is not safe. The other way is to call the binary directly but providing qemu with a prefix (-L option) in order to find the elf interpreter correctly. This way, both the target binary and dynamic loader are mapped into memory under qemu's control and, only after, the dynamic loader is started. [YOCTO #4179] Signed-off-by: Laurentiu Palcu Signed-off-by: Richard Purdie --- meta/classes/qemu.bbclass | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'meta/classes/qemu.bbclass') diff --git a/meta/classes/qemu.bbclass b/meta/classes/qemu.bbclass index 8b039266b9..0e71d6aaad 100644 --- a/meta/classes/qemu.bbclass +++ b/meta/classes/qemu.bbclass @@ -29,10 +29,4 @@ def qemu_run_binary(data, rootfs_path, binary): if qemu_binary == "qemu-allarch": qemu_binary = "qemuwrapper" - dynamic_loader = rootfs_path + '$(readelf -l ' + rootfs_path + \ - binary + '| grep "Requesting program interpreter"|sed -e \'s/^.*\[.*: \(.*\)\]/\\1/\')' - library_path = rootfs_path + data.getVar("base_libdir", True) + ":" + \ - rootfs_path + data.getVar("libdir", True) - - return "PSEUDO_UNLOAD=1 " + qemu_binary + " " + dynamic_loader + " --library-path " + library_path \ - + " " + rootfs_path + binary + return "PSEUDO_UNLOAD=1 " + qemu_binary + " -L " + rootfs_path + " " + rootfs_path + binary -- cgit v1.2.3