From 2667e069e7b5807c69f32109d930967bc1b222cb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 24 Jul 2020 07:45:01 +0100 Subject: linux-user: don't use MAP_FIXED in pgd_find_hole_fallback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Plain MAP_FIXED has the undesirable behaviour of splatting exiting maps so we don't actually achieve what we want when looking for gaps. We should be using MAP_FIXED_NOREPLACE. As this isn't always available we need to potentially check the returned address to see if the kernel gave us what we asked for. Fixes: ad592e37dfc ("linux-user: provide fallback pgd_find_hole for bare chroots") Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-Id: <20200724064509.331-9-alex.bennee@linaro.org> --- linux-user/elfload.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'linux-user') diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 7e7f642..fe9dfe7 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -2134,12 +2134,15 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, /* we have run out of space */ return -1; } else { - int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE | MAP_FIXED; + int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE | + MAP_FIXED_NOREPLACE; void * mmap_start = mmap((void *) align_start, guest_size, PROT_NONE, flags, -1, 0); if (mmap_start != MAP_FAILED) { munmap((void *) align_start, guest_size); - return (uintptr_t) mmap_start + offset; + if (MAP_FIXED_NOREPLACE || mmap_start == (void *) align_start) { + return (uintptr_t) mmap_start + offset; + } } base += qemu_host_page_size; } @@ -2307,9 +2310,8 @@ static void pgb_reserved_va(const char *image_name, abi_ulong guest_loaddr, /* Widen the "image" to the entire reserved address space. */ pgb_static(image_name, 0, reserved_va, align); -#ifdef MAP_FIXED_NOREPLACE + /* osdep.h defines this as 0 if it's missing */ flags |= MAP_FIXED_NOREPLACE; -#endif /* Reserve the memory on the host. */ assert(guest_base != 0); -- cgit v1.1 From 8ec68a0a873d24d3f81e0f34892ec4b8b1215ccf Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Fri, 24 Jul 2020 07:45:05 +0100 Subject: linux-user: fix clock_nanosleep() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If the call is interrupted by a signal handler, it fails with error EINTR and if "remain" is not NULL and "flags" is not TIMER_ABSTIME, it returns the remaining unslept time in "remain". Update linux-user to not overwrite the "remain" structure if there is no error. Found with "make check-tcg", linux-test fails on nanosleep test: TEST linux-test on x86_64 .../tests/tcg/multiarch/linux-test.c:242: nanosleep Reported-by: Philippe Mathieu-Daudé Signed-off-by: Laurent Vivier Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-Id: <20200722174612.2917566-2-laurent@vivier.eu> Message-Id: <20200724064509.331-13-alex.bennee@linaro.org> --- linux-user/syscall.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'linux-user') diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 1211e75..43a6e28 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11831,8 +11831,14 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, target_to_host_timespec(&ts, arg3); ret = get_errno(safe_clock_nanosleep(arg1, arg2, &ts, arg4 ? &ts : NULL)); - if (arg4) + /* + * if the call is interrupted by a signal handler, it fails + * with error -TARGET_EINTR and if arg4 is not NULL and arg2 is not + * TIMER_ABSTIME, it returns the remaining unslept time in arg4. + */ + if (ret == -TARGET_EINTR && arg4 && arg2 != TIMER_ABSTIME) { host_to_target_timespec(arg4, &ts); + } #if defined(TARGET_PPC) /* clock_nanosleep is odd in that it returns positive errno values. -- cgit v1.1 From 445883885a3507e3a0898df0084a59ba65ee9979 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Fri, 24 Jul 2020 07:45:06 +0100 Subject: linux-user, ppc: fix clock_nanosleep() for linux-user-ppc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Our safe_clock_nanosleep() returns -1 and updates errno. We don't need to update the CRF bit in syscall.c because it will be updated in ppc/cpu_loop.c as the return value is negative. Signed-off-by: Laurent Vivier Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-Id: <20200722174612.2917566-3-laurent@vivier.eu> Message-Id: <20200724064509.331-14-alex.bennee@linaro.org> --- linux-user/syscall.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'linux-user') diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 43a6e28..f5c4f6b 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11840,13 +11840,6 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, host_to_target_timespec(arg4, &ts); } -#if defined(TARGET_PPC) - /* clock_nanosleep is odd in that it returns positive errno values. - * On PPC, CR0 bit 3 should be set in such a situation. */ - if (ret && ret != -TARGET_ERESTARTSYS) { - ((CPUPPCState *)cpu_env)->crf[0] |= 1; - } -#endif return ret; } #endif -- cgit v1.1