This is the second half of https://patchew.org/QEMU/20230804220032.295411-1-richard.hender...@linaro.org/
which I held back because of regressions with s390x testing. It turns out that patch 4, "Use MAP_FIXED_NOREPLACE for initial image mmap" actually triggered EEXIST, which meant that probe_guest_base did not do its job to select unused host virtual memory. It's a mystery why we have not seen larger problems because of this. As I kept digging, I found quite a number of problems within probe_guest_base and its subroutines. I have rewritten it completely. Hopefully it is much easier to understand in its new form. Testing this has been difficult, because it is most visible with non-PIE executables, and most modern distros default to PIE, and our current implementation of --disable-pie does not work. r~ Helge Deller (1): linux-user: Adjust initial brk when interpreter is close to executable Richard Henderson (13): linux-user: Adjust task_unmapped_base for reserved_va linux-user: Define TASK_UNMAPPED_BASE in $guest/target_mman.h linux-user: Define ELF_ET_DYN_BASE in $guest/target_mman.h linux-user: Use MAP_FIXED_NOREPLACE for initial image mmap linux-user: Use elf_et_dyn_base for ET_DYN with interpreter linux-user: Do not adjust image mapping for host page size linux-user: Do not adjust zero_bss for host page size linux-user: Use zero_bss for PT_LOAD with no file contents too util/selfmap: Rewrite using qemu/interval-tree.h linux-user: Remove duplicate CPU_LOG_PAGE from probe_guest_base linux-user: Consolidate guest bounds check in probe_guest_base linux-user: Rewrite fixed probe_guest_base linux-user: Rewrite non-fixed probe_guest_base include/qemu/selfmap.h | 20 +- linux-user/aarch64/target_mman.h | 13 + linux-user/alpha/target_mman.h | 11 + linux-user/arm/target_mman.h | 11 + linux-user/cris/target_mman.h | 12 + linux-user/hexagon/target_mman.h | 13 + linux-user/hppa/target_mman.h | 6 + linux-user/i386/target_mman.h | 16 + linux-user/loongarch64/target_mman.h | 11 + linux-user/m68k/target_mman.h | 5 + linux-user/microblaze/target_mman.h | 11 + linux-user/mips/target_mman.h | 10 + linux-user/nios2/target_mman.h | 10 + linux-user/openrisc/target_mman.h | 10 + linux-user/ppc/target_mman.h | 20 + linux-user/qemu.h | 1 - linux-user/riscv/target_mman.h | 10 + linux-user/s390x/target_mman.h | 20 + linux-user/sh4/target_mman.h | 7 + linux-user/sparc/target_mman.h | 25 + linux-user/user-mmap.h | 5 +- linux-user/x86_64/target_mman.h | 15 + linux-user/xtensa/target_mman.h | 10 + linux-user/elfload.c | 788 +++++++++++++-------------- linux-user/main.c | 43 ++ linux-user/mmap.c | 19 +- linux-user/syscall.c | 15 +- util/selfmap.c | 114 ++-- 28 files changed, 777 insertions(+), 474 deletions(-) -- 2.34.1
