From 33143c446eb88de28ea3088b279feda8f693e398 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Mon, 16 Jul 2018 21:53:49 +0200 Subject: linux-user: fix ELF load alignment error When we try to use some targets on ppc64, it can happen the target doesn't support the host page size to align ELF load sections and fails with: ELF load command alignment not page-aligned Since commit a70daba3771 ("linux-user: Tell guest about big host page sizes") the host page size is used to align ELF sections, but this doesn't work if the alignment required by the load section is smaller than the host one. For these cases, we continue to use the TARGET_PAGE_SIZE instead of the host one. I have tested this change on ppc64, and it fixes qemu linux-user for: s390x, m68k, i386, arm, aarch64, hppa and I have tested it doesn't break the following targets: x86_64, mips64el, sh4 mips and mipsel abort, but I think for another reason. Signed-off-by: Laurent Vivier Reviewed-by: Richard Henderson [lv: fixed "info->alignment = 0"] Message-Id: <20180716195349.29959-1-laurent@vivier.eu> --- linux-user/elfload.c | 10 +++++++++- linux-user/qemu.h | 1 + 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 942a1b661f..df07055361 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1875,7 +1875,13 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, NEW_AUX_ENT(AT_PHDR, (abi_ulong)(info->load_addr + exec->e_phoff)); NEW_AUX_ENT(AT_PHENT, (abi_ulong)(sizeof (struct elf_phdr))); NEW_AUX_ENT(AT_PHNUM, (abi_ulong)(exec->e_phnum)); - NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(MAX(TARGET_PAGE_SIZE, getpagesize()))); + if ((info->alignment & ~qemu_host_page_mask) != 0) { + /* Target doesn't support host page size alignment */ + NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(TARGET_PAGE_SIZE)); + } else { + NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(MAX(TARGET_PAGE_SIZE, + qemu_host_page_size))); + } NEW_AUX_ENT(AT_BASE, (abi_ulong)(interp_info ? interp_info->load_addr : 0)); NEW_AUX_ENT(AT_FLAGS, (abi_ulong)0); NEW_AUX_ENT(AT_ENTRY, info->entry); @@ -2202,6 +2208,7 @@ static void load_elf_image(const char *image_name, int image_fd, /* Find the maximum size of the image and allocate an appropriate amount of memory to handle that. */ loaddr = -1, hiaddr = 0; + info->alignment = 0; for (i = 0; i < ehdr->e_phnum; ++i) { if (phdr[i].p_type == PT_LOAD) { abi_ulong a = phdr[i].p_vaddr - phdr[i].p_offset; @@ -2213,6 +2220,7 @@ static void load_elf_image(const char *image_name, int image_fd, hiaddr = a; } ++info->nsegs; + info->alignment |= phdr[i].p_align; } } diff --git a/linux-user/qemu.h b/linux-user/qemu.h index bb85c81aa4..7b16a1cdea 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -51,6 +51,7 @@ struct image_info { abi_ulong file_string; uint32_t elf_flags; int personality; + abi_ulong alignment; /* The fields below are used in FDPIC mode. */ abi_ulong loadmap_addr; -- cgit v1.2.3 From fa97e38eed3bbdbc322d94092ca49450e724fff1 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 18 Jul 2018 13:06:48 -0700 Subject: linux-user/ppc: Implement swapcontext syscall MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows the tests generated by debian-powerpc-user-cross to function properly, especially tests/test-coroutine. Technically this syscall is available to both ppc32 and ppc64, but only ppc32 glibc actually uses it. Thus the ppc64 path is untested. Signed-off-by: Richard Henderson Tested-by: Alex Bennée Reviewed-by: Alex Bennée Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Laurent Vivier Message-Id: <20180718200648.22529-1-richard.henderson@linaro.org> --- linux-user/ppc/signal.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++ linux-user/qemu.h | 2 ++ linux-user/syscall.c | 6 ++++++ 3 files changed, 64 insertions(+) diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c index ef4c518f11..2ae120a2bc 100644 --- a/linux-user/ppc/signal.c +++ b/linux-user/ppc/signal.c @@ -675,3 +675,59 @@ sigsegv: force_sig(TARGET_SIGSEGV); return -TARGET_QEMU_ESIGRETURN; } + +/* This syscall implements {get,set,swap}context for userland. */ +abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx, + abi_ulong unew_ctx, abi_long ctx_size) +{ + struct target_ucontext *uctx; + struct target_mcontext *mctx; + + /* For ppc32, ctx_size is "reserved for future use". + * For ppc64, we do not yet support the VSX extension. + */ + if (ctx_size < sizeof(struct target_ucontext)) { + return -TARGET_EINVAL; + } + + if (uold_ctx) { + TaskState *ts = (TaskState *)thread_cpu->opaque; + + if (!lock_user_struct(VERIFY_WRITE, uctx, uold_ctx, 1)) { + return -TARGET_EFAULT; + } + +#ifdef TARGET_PPC64 + mctx = &uctx->tuc_sigcontext.mcontext; +#else + /* ??? The kernel aligns the pointer down here into padding, but + * in setup_rt_frame we don't. Be self-compatible for now. + */ + mctx = &uctx->tuc_mcontext; + __put_user(h2g(mctx), &uctx->tuc_regs); +#endif + + save_user_regs(env, mctx); + host_to_target_sigset(&uctx->tuc_sigmask, &ts->signal_mask); + + unlock_user_struct(uctx, uold_ctx, 1); + } + + if (unew_ctx) { + int err; + + if (!lock_user_struct(VERIFY_READ, uctx, unew_ctx, 1)) { + return -TARGET_EFAULT; + } + err = do_setcontext(uctx, env, 0); + unlock_user_struct(uctx, unew_ctx, 1); + + if (err) { + /* We cannot return to a partially updated context. */ + force_sig(TARGET_SIGSEGV); + } + return -TARGET_QEMU_ESIGRETURN; + } + + return 0; +} diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 7b16a1cdea..b4959e41c6 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -396,6 +396,8 @@ long do_sigreturn(CPUArchState *env); long do_rt_sigreturn(CPUArchState *env); abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp); int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset); +abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx, + abi_ulong unew_ctx, abi_long ctx_size); /** * block_signals: block all signals while handling this guest syscall * diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 3df3bdffb2..dfc851cc35 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -12790,6 +12790,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, ret = get_errno(kcmp(arg1, arg2, arg3, arg4, arg5)); break; #endif +#ifdef TARGET_NR_swapcontext + case TARGET_NR_swapcontext: + /* PowerPC specific. */ + ret = do_swapcontext(cpu_env, arg1, arg2, arg3); + break; +#endif default: unimplemented: -- cgit v1.2.3