Hi Joelle, On 11/8/20 6:26 AM, Joelle van Dyne wrote: > iOS does not support ucontext natively for aarch64 and the sigaltstack is > also unsupported (even worse, it fails silently, see: > https://openradar.appspot.com/13002712 ) > > As a workaround we include a library implementation of ucontext and add it > as a build option. > > Signed-off-by: Joelle van Dyne <j...@getutm.app> > --- > configure | 23 ++++++++++++++++++++--- > meson.build | 28 +++++++++++++++++++++++++++- > util/coroutine-ucontext.c | 9 +++++++++ > .gitmodules | 3 +++ > libucontext | 1 + > meson_options.txt | 2 ++ > 6 files changed, 62 insertions(+), 4 deletions(-) > create mode 160000 libucontext ...
> diff --git a/meson.build b/meson.build > index 8894171bd1..e62324d5ac 100644 > --- a/meson.build > +++ b/meson.build > @@ -1259,9 +1259,34 @@ if not fdt.found() and fdt_required.length() > 0 > error('fdt not available but required by targets ' + ', > '.join(fdt_required)) > endif > > +ucontext = not_found > +if get_option('ucontext').enabled() > + if not fs.is_dir(meson.current_source_dir() / 'libucontext/arch' / cpu) > + error('libucontext is wanted but not implemented for host ' + cpu) > + endif > + arch = host_machine.cpu() > + ucontext_cargs = ['-DG_LOG_DOMAIN="ucontext"', '-DCUSTOM_IMPL'] > + ucontext_files = [ > + 'libucontext/arch' / arch / 'getcontext.S', > + 'libucontext/arch' / arch / 'setcontext.S', > + 'libucontext/arch' / arch / 'makecontext.c', > + 'libucontext/arch' / arch / 'startcontext.S', > + 'libucontext/arch' / arch / 'swapcontext.S', > + ] > + > + ucontext_inc = include_directories('libucontext/include') > + libucontext = static_library('ucontext', > + sources: ucontext_files, > + c_args: ucontext_cargs, > + include_directories: ucontext_inc) > + ucontext = declare_dependency(link_with: libucontext, > + include_directories: ucontext_inc) > +endif > + > config_host_data.set('CONFIG_CAPSTONE', capstone.found()) > config_host_data.set('CONFIG_FDT', fdt.found()) > config_host_data.set('CONFIG_SLIRP', slirp.found()) > +config_host_data.set('CONFIG_LIBUCONTEXT', ucontext.found()) > > ##################### > # Generated sources # > @@ -1477,7 +1502,7 @@ util_ss.add_all(trace_ss) > util_ss = util_ss.apply(config_all, strict: false) > libqemuutil = static_library('qemuutil', > sources: util_ss.sources() + stub_ss.sources() > + genh, > - dependencies: [util_ss.dependencies(), m, glib, > socket, malloc]) > + dependencies: [util_ss.dependencies(), m, glib, > socket, malloc, ucontext]) > qemuutil = declare_dependency(link_with: libqemuutil, > sources: genh + version_res) > > @@ -2135,6 +2160,7 @@ if targetos == 'windows' > summary_info += {'QGA MSI support': > config_host.has_key('CONFIG_QGA_MSI')} > endif > summary_info += {'seccomp support': config_host.has_key('CONFIG_SECCOMP')} > +summary_info += {'libucontext support': ucontext.found()} > summary_info += {'coroutine backend': > config_host['CONFIG_COROUTINE_BACKEND']} > summary_info += {'coroutine pool': config_host['CONFIG_COROUTINE_POOL'] > == '1'} > summary_info += {'debug stack usage': > config_host.has_key('CONFIG_DEBUG_STACK_USAGE')} > diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c > index 904b375192..1e1dd43512 100644 > --- a/util/coroutine-ucontext.c > +++ b/util/coroutine-ucontext.c > @@ -23,7 +23,16 @@ > #undef _FORTIFY_SOURCE > #endif > #include "qemu/osdep.h" > +#if defined(CONFIG_LIBUCONTEXT) > +#include <libucontext.h> > +#define ucontext_t libucontext_ucontext_t > +#define getcontext libucontext_getcontext > +#define setcontext libucontext_setcontext > +#define swapcontext libucontext_swapcontext > +#define makecontext libucontext_makecontext > +#else > #include <ucontext.h> > +#endif > #include "qemu/coroutine_int.h" Trying on Ubuntu 20.04 I'm getting: /usr/bin/ld: libqemuutil.a(util_coroutine-ucontext.c.o): in function `qemu_coroutine_new': util/coroutine-ucontext.c:203: undefined reference to `libucontext_getcontext' /usr/bin/ld: util/coroutine-ucontext.c:254: undefined reference to `libucontext_swapcontext' /usr/bin/ld: libucontext.a(libucontext_arch_x86_64_makecontext.c.o): in function `libucontext_makecontext': libucontext/arch/x86_64/makecontext.c:54: undefined reference to `_start_context' collect2: error: ld returned 1 exit status Regards, Phil.