## Host environment - Operating system: postmarketOS edge - OS/kernel version: 6.19.11 #1-postmarketos-asahi SMP PREEMPT Tue Apr 14 05:33:03 UTC 2026 aarch64 GNU/Linux - Architecture: aarch64 (Apple M2 Si w/ 16K pages) - QEMU flavor: qemu-arm - QEMU version: 10.2.2 - QEMU command line: chroot with qemu-arm binfmt (see steps to repro...) ## Emulated/Virtualized environment - Operating system: Alpine Linux - OS/kernel version: (same as host) - Architecture: arm (32-bit) ## Description of problem mremap returns EFAULT under qemu-user when the host page size (16K) is larger than the guest page size (4K). I don't know for sure that the page size difference is the cause, but I've not heard of others having this issue when using 4K pages on other aarch64 systems with qemu-arm. ## Steps to reproduce ``` $ getconf PAGESIZE 16384 $ cat /proc/sys/fs/binfmt_misc/qemu-arm enabled interpreter /usr/bin/qemu-arm flags: OCF offset 0 magic 7f454c46010101 mask ffffffffffffff $ curl -O https://dl-cdn.alpinelinux.org/alpine/v3.23/releases/armv7/alpine-minirootfs-3.23.4-armv7.tar.gz $ tar xf alpine-minirootfs-3.23.4-armv7.tar.gz $ sudo chroot . /bin/sh / # uname -m armv7l / # getconf PAGESIZE 4096 / # sed -i 's|v3.23|edge|' /etc/apk/repositories / # apk upgrade ... OK:... / # apk upgrade qemu: uncaught target signal 11 (Segmentation fault) - core dumped Segmentation fault (core dumped) ``` ## Additional information ``` / # QEMU_STRACE=1 apk upgrade ... 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x429a0000 222884 munmap(0x427ac000,65536) = 0 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x427ac000 222884 munmap(0x42750000,65536) = 0 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x42748000 222884 munmap(0x427bc000,65536) = 0 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x427bc000 222884 munmap(0x42590000,65536) = 0 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x42590000 222884 munmap(0x425a0000,65536) = 0 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x425a0000 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x429b0000 222884 munmap(0x425b0000,65536) = 0 222884 mmap2(NULL,65536,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x425b0000 222884 mmap2(NULL,16384,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x421b8000 222884 mmap2(NULL,16384,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x422cc000 222884 mmap2(NULL,32768,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x423d0000 222884 mmap2(NULL,36864,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x42644000 222884 munmap(0x427cc000,1048576) = 0 222884 munmap(0x424b8000,65536) = 0 222884 munmap(0x4235c000,32768) = 0 222884 munmap(0x423b8000,32768) = 0 222884 mmap2(NULL,8192,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x422d8000 222884 mremap(1117175808,147456,151552,1,0,4363216) = -1 errno=14 (Bad address) 222884 mmap2(NULL,145172,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0) = 0x427cc000 --- SIGSEGV {si_signo=SIGSEGV, si_code=2, si_addr=0x4296c920} --- qemu: uncaught target signal 11 (Segmentation fault) - core dumped Segmentation fault (core dumped) ``` <!-- The line below ensures that proper tags are added to the issue. Please do not remove it. -->