From fb7f3572b111ffb6c2dd2c7f6c5b4dc57dd8a3f5 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Wed, 23 Oct 2024 02:24:31 +0200 Subject: [PATCH] linux-user: Tolerate CONFIG_LSM_MMAP_MIN_ADDR Running qemu-i386 on a system running with SELinux in enforcing mode (more precisely: s390x trixie container on Fedora 40) fails with: qemu-i386: tests/tcg/i386-linux-user/sigreturn-sigmask: Unable to find a guest_base to satisfy all guest address mapping requirements 00000000-ffffffff The reason is that main() determines mmap_min_addr from /proc/sys/vm/mmap_min_addr, but SELinux additionally defines CONFIG_LSM_MMAP_MIN_ADDR, which is normally larger: 32K or 64K, but, in general, can be anything. There is no portable way to query its value: /boot/config, /proc/config and /proc/config.gz are distro- and environment-specific. Once the identity map fails, the magnitude of guest_base does not matter, so fix by starting the search from 1M or 1G. Cc: qemu-stable@nongnu.org Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2598 Suggested-by: Richard Henderson Signed-off-by: Ilya Leoshkevich Message-ID: <20241023002558.34589-1-iii@linux.ibm.com> Signed-off-by: Richard Henderson --- linux-user/elfload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 6cef8db3b5..d6ad77d27d 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -2898,7 +2898,7 @@ static uintptr_t pgb_try_itree(const PGBAddrs *ga, uintptr_t base, static uintptr_t pgb_find_itree(const PGBAddrs *ga, IntervalTreeRoot *root, uintptr_t align, uintptr_t brk) { - uintptr_t last = mmap_min_addr; + uintptr_t last = sizeof(uintptr_t) == 4 ? MiB : GiB; uintptr_t base, skip; while (true) { -- 2.30.2