From 49840a4a098149067789255bca6894645f411036 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 6 Mar 2023 01:51:09 +0300 Subject: accel/tcg: Pass last not end to page_set_flags MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Pass the address of the last byte to be changed, rather than the first address past the last byte. This avoids overflow when the last page of the address space is involved. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1528 Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- linux-user/elfload.c | 11 ++++++----- linux-user/mmap.c | 16 ++++++++-------- linux-user/syscall.c | 4 ++-- 3 files changed, 16 insertions(+), 15 deletions(-) (limited to 'linux-user') diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 1dbc1f0..fa4cc41 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -213,7 +213,7 @@ static bool init_guest_commpage(void) exit(EXIT_FAILURE); } page_set_flags(TARGET_VSYSCALL_PAGE, - TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE, + TARGET_VSYSCALL_PAGE | ~TARGET_PAGE_MASK, PAGE_EXEC | PAGE_VALID); return true; } @@ -444,7 +444,7 @@ static bool init_guest_commpage(void) exit(EXIT_FAILURE); } - page_set_flags(commpage, commpage + qemu_host_page_size, + page_set_flags(commpage, commpage | ~qemu_host_page_mask, PAGE_READ | PAGE_EXEC | PAGE_VALID); return true; } @@ -1316,7 +1316,7 @@ static bool init_guest_commpage(void) exit(EXIT_FAILURE); } - page_set_flags(LO_COMMPAGE, LO_COMMPAGE + TARGET_PAGE_SIZE, + page_set_flags(LO_COMMPAGE, LO_COMMPAGE | ~TARGET_PAGE_MASK, PAGE_READ | PAGE_EXEC | PAGE_VALID); return true; } @@ -1728,7 +1728,7 @@ static bool init_guest_commpage(void) * and implement syscalls. Here, simply mark the page executable. * Special case the entry points during translation (see do_page_zero). */ - page_set_flags(LO_COMMPAGE, LO_COMMPAGE + TARGET_PAGE_SIZE, + page_set_flags(LO_COMMPAGE, LO_COMMPAGE | ~TARGET_PAGE_MASK, PAGE_EXEC | PAGE_VALID); return true; } @@ -2209,7 +2209,8 @@ static void zero_bss(abi_ulong elf_bss, abi_ulong last_bss, int prot) /* Ensure that the bss page(s) are valid */ if ((page_get_flags(last_bss-1) & prot) != prot) { - page_set_flags(elf_bss & TARGET_PAGE_MASK, last_bss, prot | PAGE_VALID); + page_set_flags(elf_bss & TARGET_PAGE_MASK, last_bss - 1, + prot | PAGE_VALID); } if (host_start < host_map_start) { diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 28135c9..1d07ff5 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -181,7 +181,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot) } } - page_set_flags(start, start + len, page_flags); + page_set_flags(start, start + len - 1, page_flags); ret = 0; error: @@ -640,15 +640,15 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, } page_flags |= PAGE_RESET; if (passthrough_start == passthrough_end) { - page_set_flags(start, start + len, page_flags); + page_set_flags(start, start + len - 1, page_flags); } else { if (start < passthrough_start) { - page_set_flags(start, passthrough_start, page_flags); + page_set_flags(start, passthrough_start - 1, page_flags); } - page_set_flags(passthrough_start, passthrough_end, + page_set_flags(passthrough_start, passthrough_end - 1, page_flags | PAGE_PASSTHROUGH); if (passthrough_end < start + len) { - page_set_flags(passthrough_end, start + len, page_flags); + page_set_flags(passthrough_end, start + len - 1, page_flags); } } the_end: @@ -763,7 +763,7 @@ int target_munmap(abi_ulong start, abi_ulong len) } if (ret == 0) { - page_set_flags(start, start + len, 0); + page_set_flags(start, start + len - 1, 0); } mmap_unlock(); return ret; @@ -849,8 +849,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, } else { new_addr = h2g(host_addr); prot = page_get_flags(old_addr); - page_set_flags(old_addr, old_addr + old_size, 0); - page_set_flags(new_addr, new_addr + new_size, + page_set_flags(old_addr, old_addr + old_size - 1, 0); + page_set_flags(new_addr, new_addr + new_size - 1, prot | PAGE_VALID | PAGE_RESET); } mmap_unlock(); diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 2787164..69f740f 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -4595,7 +4595,7 @@ static inline abi_ulong do_shmat(CPUArchState *cpu_env, } raddr=h2g((unsigned long)host_raddr); - page_set_flags(raddr, raddr + shm_info.shm_segsz, + page_set_flags(raddr, raddr + shm_info.shm_segsz - 1, PAGE_VALID | PAGE_RESET | PAGE_READ | (shmflg & SHM_RDONLY ? 0 : PAGE_WRITE)); @@ -4625,7 +4625,7 @@ static inline abi_long do_shmdt(abi_ulong shmaddr) for (i = 0; i < N_SHM_REGIONS; ++i) { if (shm_regions[i].in_use && shm_regions[i].start == shmaddr) { shm_regions[i].in_use = false; - page_set_flags(shmaddr, shmaddr + shm_regions[i].size, 0); + page_set_flags(shmaddr, shmaddr + shm_regions[i].size - 1, 0); break; } } -- cgit v1.1