Re: [PATCH v4 47/53] semihosting: Create qemu_semihosting_guestfd_init

[Luc Michel]

On 13:45 Tue 07 Jun     , Richard Henderson wrote:
> For arm-compat, initialize console_{in,out}_gf;
> otherwise, initialize stdio file descriptors.
> 
> This will go some way to cleaning up arm-compat, and
> will allow other semihosting to use normal stdio.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Luc Michel <lmichel@kalray.eu>

> ---
>  include/semihosting/guestfd.h  |  7 +++++
>  include/semihosting/semihost.h |  1 +
>  linux-user/main.c              |  9 ++++++
>  semihosting/console.c          |  2 ++
>  semihosting/guestfd.c          | 52 +++++++++++++++++++++++++++-------
>  5 files changed, 61 insertions(+), 10 deletions(-)
> 
> diff --git a/include/semihosting/guestfd.h b/include/semihosting/guestfd.h
> index a7ea1041ea..3d426fedab 100644
> --- a/include/semihosting/guestfd.h
> +++ b/include/semihosting/guestfd.h
> @@ -35,6 +35,13 @@ typedef struct GuestFD {
>      };
>  } GuestFD;
>  
> +/*
> + * For ARM semihosting, we have a separate structure for routing
> + * data for the console which is outside the guest fd address space.
> + */
> +extern GuestFD console_in_gf;
> +extern GuestFD console_out_gf;
> +
>  /**
>   * alloc_guestfd:
>   *
> diff --git a/include/semihosting/semihost.h b/include/semihosting/semihost.h
> index 5b36a76f08..93a3c21b44 100644
> --- a/include/semihosting/semihost.h
> +++ b/include/semihosting/semihost.h
> @@ -64,5 +64,6 @@ int qemu_semihosting_config_options(const char *opt);
>  void qemu_semihosting_chardev_init(void);
>  void qemu_semihosting_console_init(Chardev *);
>  #endif /* CONFIG_USER_ONLY */
> +void qemu_semihosting_guestfd_init(void);
>  
>  #endif /* SEMIHOST_H */
> diff --git a/linux-user/main.c b/linux-user/main.c
> index 651e32f5f2..e44bdb17b8 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -54,6 +54,10 @@
>  #include "loader.h"
>  #include "user-mmap.h"
>  
> +#ifdef CONFIG_SEMIHOSTING
> +#include "semihosting/semihost.h"
> +#endif
> +
>  #ifndef AT_FLAGS_PRESERVE_ARGV0
>  #define AT_FLAGS_PRESERVE_ARGV0_BIT 0
>  #define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> @@ -906,6 +910,11 @@ int main(int argc, char **argv, char **envp)
>          }
>          gdb_handlesig(cpu, 0);
>      }
> +
> +#ifdef CONFIG_SEMIHOSTING
> +    qemu_semihosting_guestfd_init();
> +#endif
> +
>      cpu_loop(env);
>      /* never exits */
>      return 0;
> diff --git a/semihosting/console.c b/semihosting/console.c
> index b6a342744d..677ec2b176 100644
> --- a/semihosting/console.c
> +++ b/semihosting/console.c
> @@ -190,4 +190,6 @@ void qemu_semihosting_console_init(Chardev *chr)
>                                   NULL, NULL, &console,
>                                   NULL, true);
>      }
> +
> +    qemu_semihosting_guestfd_init();
>  }
> diff --git a/semihosting/guestfd.c b/semihosting/guestfd.c
> index e3122ebba9..b05c52f26f 100644
> --- a/semihosting/guestfd.c
> +++ b/semihosting/guestfd.c
> @@ -10,15 +10,56 @@
>  
>  #include "qemu/osdep.h"
>  #include "exec/gdbstub.h"
> +#include "semihosting/semihost.h"
>  #include "semihosting/guestfd.h"
>  #ifdef CONFIG_USER_ONLY
>  #include "qemu.h"
>  #else
>  #include "semihosting/softmmu-uaccess.h"
> +#include CONFIG_DEVICES
>  #endif
>  
>  static GArray *guestfd_array;
>  
> +#ifdef CONFIG_ARM_COMPATIBLE_SEMIHOSTING
> +GuestFD console_in_gf;
> +GuestFD console_out_gf;
> +#endif
> +
> +void qemu_semihosting_guestfd_init(void)
> +{
> +    /* New entries zero-initialized, i.e. type GuestFDUnused */
> +    guestfd_array = g_array_new(FALSE, TRUE, sizeof(GuestFD));
> +
> +#ifdef CONFIG_ARM_COMPATIBLE_SEMIHOSTING
> +    /* For ARM-compat, the console is in a separate namespace. */
> +    if (use_gdb_syscalls()) {
> +        console_in_gf.type = GuestFDGDB;
> +        console_in_gf.hostfd = 0;
> +        console_out_gf.type = GuestFDGDB;
> +        console_out_gf.hostfd = 2;
> +    } else {
> +        console_in_gf.type = GuestFDConsole;
> +        console_out_gf.type = GuestFDConsole;
> +    }
> +#else
> +    /* Otherwise, the stdio file descriptors apply. */
> +    guestfd_array = g_array_set_size(guestfd_array, 3);
> +#ifndef CONFIG_USER_ONLY
> +    if (!use_gdb_syscalls()) {
> +        GuestFD *gf = &g_array_index(guestfd_array, GuestFD, 0);
> +        gf[0].type = GuestFDConsole;
> +        gf[1].type = GuestFDConsole;
> +        gf[2].type = GuestFDConsole;
> +        return;
> +    }
> +#endif
> +    associate_guestfd(0, 0);
> +    associate_guestfd(1, 1);
> +    associate_guestfd(2, 2);
> +#endif
> +}
> +
>  /*
>   * Allocate a new guest file descriptor and return it; if we
>   * couldn't allocate a new fd then return -1.
> @@ -30,11 +71,6 @@ int alloc_guestfd(void)
>  {
>      guint i;
>  
> -    if (!guestfd_array) {
> -        /* New entries zero-initialized, i.e. type GuestFDUnused */
> -        guestfd_array = g_array_new(FALSE, TRUE, sizeof(GuestFD));
> -    }
> -
>      /* SYS_OPEN should return nonzero handle on success. Start guestfd from 
> 1 */
>      for (i = 1; i < guestfd_array->len; i++) {
>          GuestFD *gf = &g_array_index(guestfd_array, GuestFD, i);
> @@ -61,11 +97,7 @@ static void do_dealloc_guestfd(GuestFD *gf)
>   */
>  static GuestFD *do_get_guestfd(int guestfd)
>  {
> -    if (!guestfd_array) {
> -        return NULL;
> -    }
> -
> -    if (guestfd <= 0 || guestfd >= guestfd_array->len) {
> +    if (guestfd < 0 || guestfd >= guestfd_array->len) {
>          return NULL;
>      }
>  
> -- 
> 2.34.1
> 
> 
> 
> 
> To declare a filtering error, please use the following link : 
> https://www.security-mail.net/reporter.php?mid=1370f.629fd794.51215.0&r=lmichel%40kalrayinc.com&s=qemu-devel-bounces%2Blmichel%3Dkalrayinc.com%40nongnu.org&o=%5BPATCH+v4+47%2F53%5D+semihosting%3A+Create+qemu_semihosting_guestfd_init&verdict=C&c=8a62784599ce0d3c84c0909196f346103514fbcc
> 

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