Re: [PATCH 22/41] include: move qemu_*_exec_dir() to cutils

[Daniel P . Berrangé]

On Wed, Apr 20, 2022 at 05:26:05PM +0400, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> The function is required by get_relocated_path(), which is used by
> qemu-ga and may be generally useful.

In patch 06 I suggested we have a qemu-cli.h, and perhaps this
qemu_*_exec_dir functionality is also relevant for qemu-cli.{c,h}
since it is specific to command line tool initialization.

> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  include/qemu/cutils.h                |   7 ++
>  include/qemu/osdep.h                 |   8 --
>  qemu-io.c                            |   1 +
>  storage-daemon/qemu-storage-daemon.c |   1 +
>  tests/qtest/fuzz/fuzz.c              |   1 +
>  util/cutils.c                        | 109 +++++++++++++++++++++++++++
>  util/oslib-posix.c                   |  81 --------------------
>  util/oslib-win32.c                   |  36 ---------
>  8 files changed, 119 insertions(+), 125 deletions(-)
> 
> diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
> index 5c6572d44422..40e10e19a7ed 100644
> --- a/include/qemu/cutils.h
> +++ b/include/qemu/cutils.h
> @@ -193,6 +193,13 @@ int uleb128_decode_small(const uint8_t *in, uint32_t *n);
>   */
>  int qemu_pstrcmp0(const char **str1, const char **str2);
>  
> +/* Find program directory, and save it for later usage with
> + * qemu_get_exec_dir().
> + * Try OS specific API first, if not working, parse from argv0. */
> +void qemu_init_exec_dir(const char *argv0);
> +
> +/* Get the saved exec dir.  */
> +const char *qemu_get_exec_dir(void);
>  
>  /**
>   * get_relocated_path:
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index a87f1b7f32e6..9fd52d6a33a7 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -567,14 +567,6 @@ bool fips_get_state(void);
>   */
>  char *qemu_get_local_state_pathname(const char *relative_pathname);
>  
> -/* Find program directory, and save it for later usage with
> - * qemu_get_exec_dir().
> - * Try OS specific API first, if not working, parse from argv0. */
> -void qemu_init_exec_dir(const char *argv0);
> -
> -/* Get the saved exec dir.  */
> -const char *qemu_get_exec_dir(void);
> -
>  /**
>   * qemu_getauxval:
>   * @type: the auxiliary vector key to lookup
> diff --git a/qemu-io.c b/qemu-io.c
> index 952a36643b0c..458fadd99a92 100644
> --- a/qemu-io.c
> +++ b/qemu-io.c
> @@ -16,6 +16,7 @@
>  #endif
>  
>  #include "qemu/copyright.h"
> +#include "qemu/cutils.h"
>  #include "qapi/error.h"
>  #include "qemu-io.h"
>  #include "qemu/error-report.h"
> diff --git a/storage-daemon/qemu-storage-daemon.c 
> b/storage-daemon/qemu-storage-daemon.c
> index a4415e8c995b..63b155013ed7 100644
> --- a/storage-daemon/qemu-storage-daemon.c
> +++ b/storage-daemon/qemu-storage-daemon.c
> @@ -44,6 +44,7 @@
>  
>  #include "qemu/copyright.h"
>  #include "qemu-version.h"
> +#include "qemu/cutils.h"
>  #include "qemu/config-file.h"
>  #include "qemu/error-report.h"
>  #include "qemu/help_option.h"
> diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c
> index 5f77c849837f..d3afd294db24 100644
> --- a/tests/qtest/fuzz/fuzz.c
> +++ b/tests/qtest/fuzz/fuzz.c
> @@ -15,6 +15,7 @@
>  
>  #include <wordexp.h>
>  
> +#include "qemu/cutils.h"
>  #include "qemu/datadir.h"
>  #include "sysemu/sysemu.h"
>  #include "sysemu/qtest.h"
> diff --git a/util/cutils.c b/util/cutils.c
> index b2777210e7da..443927275fdb 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -931,6 +931,115 @@ static inline const char *next_component(const char 
> *dir, int *p_len)
>      return dir;
>  }
>  
> +static const char *exec_dir;
> +
> +void qemu_init_exec_dir(const char *argv0)
> +{
> +#ifdef G_OS_WIN32
> +    char *p;
> +    char buf[MAX_PATH];
> +    DWORD len;
> +
> +    if (exec_dir) {
> +        return;
> +    }
> +
> +    len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
> +    if (len == 0) {
> +        return;
> +    }
> +
> +    buf[len] = 0;
> +    p = buf + len - 1;
> +    while (p != buf && *p != '\\') {
> +        p--;
> +    }
> +    *p = 0;
> +    if (access(buf, R_OK) == 0) {
> +        exec_dir = g_strdup(buf);
> +    } else {
> +        exec_dir = CONFIG_BINDIR;
> +    }
> +#else
> +    char *p = NULL;
> +    char buf[PATH_MAX];
> +
> +    if (exec_dir) {
> +        return;
> +    }
> +
> +#if defined(__linux__)
> +    {
> +        int len;
> +        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
> +        if (len > 0) {
> +            buf[len] = 0;
> +            p = buf;
> +        }
> +    }
> +#elif defined(__FreeBSD__) \
> +      || (defined(__NetBSD__) && defined(KERN_PROC_PATHNAME))
> +    {
> +#if defined(__FreeBSD__)
> +        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
> +#else
> +        static int mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, 
> KERN_PROC_PATHNAME};
> +#endif
> +        size_t len = sizeof(buf) - 1;
> +
> +        *buf = '\0';
> +        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
> +            *buf) {
> +            buf[sizeof(buf) - 1] = '\0';
> +            p = buf;
> +        }
> +    }
> +#elif defined(__APPLE__)
> +    {
> +        char fpath[PATH_MAX];
> +        uint32_t len = sizeof(fpath);
> +        if (_NSGetExecutablePath(fpath, &len) == 0) {
> +            p = realpath(fpath, buf);
> +            if (!p) {
> +                return;
> +            }
> +        }
> +    }
> +#elif defined(__HAIKU__)
> +    {
> +        image_info ii;
> +        int32_t c = 0;
> +
> +        *buf = '\0';
> +        while (get_next_image_info(0, &c, &ii) == B_OK) {
> +            if (ii.type == B_APP_IMAGE) {
> +                strncpy(buf, ii.name, sizeof(buf));
> +                buf[sizeof(buf) - 1] = 0;
> +                p = buf;
> +                break;
> +            }
> +        }
> +    }
> +#endif
> +    /* If we don't have any way of figuring out the actual executable
> +       location then try argv[0].  */
> +    if (!p && argv0) {
> +        p = realpath(argv0, buf);
> +    }
> +    if (p) {
> +        exec_dir = g_path_get_dirname(p);
> +    } else {
> +        exec_dir = CONFIG_BINDIR;
> +    }
> +#endif
> +}
> +
> +const char *qemu_get_exec_dir(void)
> +{
> +    return exec_dir;
> +}
> +
> +
>  char *get_relocated_path(const char *dir)
>  {
>      size_t prefix_len = strlen(CONFIG_PREFIX);
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index 161f1123259f..4f18cc612850 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -321,87 +321,6 @@ void qemu_set_tty_echo(int fd, bool echo)
>      tcsetattr(fd, TCSANOW, &tty);
>  }
>  
> -static const char *exec_dir;
> -
> -void qemu_init_exec_dir(const char *argv0)
> -{
> -    char *p = NULL;
> -    char buf[PATH_MAX];
> -
> -    if (exec_dir) {
> -        return;
> -    }
> -
> -#if defined(__linux__)
> -    {
> -        int len;
> -        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
> -        if (len > 0) {
> -            buf[len] = 0;
> -            p = buf;
> -        }
> -    }
> -#elif defined(__FreeBSD__) \
> -      || (defined(__NetBSD__) && defined(KERN_PROC_PATHNAME))
> -    {
> -#if defined(__FreeBSD__)
> -        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
> -#else
> -        static int mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, 
> KERN_PROC_PATHNAME};
> -#endif
> -        size_t len = sizeof(buf) - 1;
> -
> -        *buf = '\0';
> -        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
> -            *buf) {
> -            buf[sizeof(buf) - 1] = '\0';
> -            p = buf;
> -        }
> -    }
> -#elif defined(__APPLE__)
> -    {
> -        char fpath[PATH_MAX];
> -        uint32_t len = sizeof(fpath);
> -        if (_NSGetExecutablePath(fpath, &len) == 0) {
> -            p = realpath(fpath, buf);
> -            if (!p) {
> -                return;
> -            }
> -        }
> -    }
> -#elif defined(__HAIKU__)
> -    {
> -        image_info ii;
> -        int32_t c = 0;
> -
> -        *buf = '\0';
> -        while (get_next_image_info(0, &c, &ii) == B_OK) {
> -            if (ii.type == B_APP_IMAGE) {
> -                strncpy(buf, ii.name, sizeof(buf));
> -                buf[sizeof(buf) - 1] = 0;
> -                p = buf;
> -                break;
> -            }
> -        }
> -    }
> -#endif
> -    /* If we don't have any way of figuring out the actual executable
> -       location then try argv[0].  */
> -    if (!p && argv0) {
> -        p = realpath(argv0, buf);
> -    }
> -    if (p) {
> -        exec_dir = g_path_get_dirname(p);
> -    } else {
> -        exec_dir = CONFIG_BINDIR;
> -    }
> -}
> -
> -const char *qemu_get_exec_dir(void)
> -{
> -    return exec_dir;
> -}
> -
>  #ifdef CONFIG_LINUX
>  static void sigbus_handler(int signal, siginfo_t *siginfo, void *ctx)
>  #else /* CONFIG_LINUX */
> diff --git a/util/oslib-win32.c b/util/oslib-win32.c
> index 1e05c316b311..0371082d23b3 100644
> --- a/util/oslib-win32.c
> +++ b/util/oslib-win32.c
> @@ -270,42 +270,6 @@ void qemu_set_tty_echo(int fd, bool echo)
>      }
>  }
>  
> -static const char *exec_dir;
> -
> -void qemu_init_exec_dir(const char *argv0)
> -{
> -
> -    char *p;
> -    char buf[MAX_PATH];
> -    DWORD len;
> -
> -    if (exec_dir) {
> -        return;
> -    }
> -
> -    len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
> -    if (len == 0) {
> -        return;
> -    }
> -
> -    buf[len] = 0;
> -    p = buf + len - 1;
> -    while (p != buf && *p != '\\') {
> -        p--;
> -    }
> -    *p = 0;
> -    if (access(buf, R_OK) == 0) {
> -        exec_dir = g_strdup(buf);
> -    } else {
> -        exec_dir = CONFIG_BINDIR;
> -    }
> -}
> -
> -const char *qemu_get_exec_dir(void)
> -{
> -    return exec_dir;
> -}
> -
>  int getpagesize(void)
>  {
>      SYSTEM_INFO system_info;
> -- 
> 2.35.1.693.g805e0a68082a
> 
> 

With regards,
Daniel
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