Yeqi Fu <fufuyqqq...@gmail.com> writes:
> This commit implements the -native-bypass support in linux-user. The
> native_calls_enabled() function can be true only when the
> '-native-bypass' option is given.
>
> Signed-off-by: Yeqi Fu <fufuyqqq...@gmail.com>
> ---
> linux-user/main.c | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/linux-user/main.c b/linux-user/main.c
> index 5e6b2e1714..98e31c77d5 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -60,6 +60,13 @@
> #include "semihosting/semihost.h"
> #endif
>
> +#if defined(CONFIG_NATIVE_CALL)
> +#include "native/native-defs.h"
> +
> +static const char *native_lib;
> +bool native_bypass_enabled;
This bool feels redundant if we can check for a non-null native-lib. You
could certainly expose a function though:
bool native_bypass_enabled() {
return native_lib ? true : false;
}
?
> +#endif
> +
> #ifndef AT_FLAGS_PRESERVE_ARGV0
> #define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> #define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> @@ -125,6 +132,7 @@ static void usage(int exitcode);
> static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
> const char *qemu_uname_release;
>
> +
rm whitespace
> #if !defined(TARGET_DEFAULT_STACK_SIZE)
> /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
> we allocate a bigger stack. Need a better solution, for example
> @@ -293,6 +301,18 @@ static void handle_arg_set_env(const char *arg)
> free(r);
> }
>
> +#if defined(CONFIG_NATIVE_CALL)
> +static void handle_arg_native_bypass(const char *arg)
> +{
> + if (access(arg, F_OK) != 0) {
> + fprintf(stderr, "native library %s does not exist\n", arg);
> + exit(EXIT_FAILURE);
> + }
> + native_lib = arg;
> + native_bypass_enabled = true;
> +}
> +#endif
> +
> static void handle_arg_unset_env(const char *arg)
> {
> char *r, *p, *token;
> @@ -522,6 +542,10 @@ static const struct qemu_argument arg_table[] = {
> "", "Generate a /tmp/perf-${pid}.map file for perf"},
> {"jitdump", "QEMU_JITDUMP", false, handle_arg_jitdump,
> "", "Generate a jit-${pid}.dump file for perf"},
> +#if defined(CONFIG_NATIVE_CALL)
> + {"native-bypass", "QEMU_NATIVE_BYPASS", true, handle_arg_native_bypass,
> + "", "native bypass for library calls in user mode only."},
> +#endif
> {NULL, NULL, false, NULL, NULL, NULL}
> };
>
> @@ -826,6 +850,18 @@ int main(int argc, char **argv, char **envp)
> }
> }
>
> +#if defined(CONFIG_NATIVE_CALL)
> + /* Set the library for native bypass */
> + if (native_bypass_enabled) {
Then this could be:
if (native_lib && g_file_test(native_lib, G_FILE_TEST_EXITS)) {
Or maybe better:
if (native_lib) {
if (g_file_test(native_lib, G_FILE_TEST_EXITS)) {
.. setup ..
} else {
fprintf(stderr, "can't open %s\n", native_lib);
exit(EXIT_FAILURE);
}
}
> + GString *lib = g_string_new(native_lib);
> + lib = g_string_prepend(lib, "LD_PRELOAD=");
> + if (envlist_appendenv(envlist, g_string_free(lib, false), ":") != 0)
> {
> + fprintf(stderr,
> + "failed to append the native library to environment.\n");
> + exit(EXIT_FAILURE);
> + }
> + }
> +#endif
> target_environ = envlist_to_environ(envlist, NULL);
> envlist_free(envlist);
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
