Re: [PATCH 3/4] Remove a use of target_read_string

[Sergio Durigan Junior <sergiodj@sergiodj.net>]

On Friday, June 12 2020, Tom Tromey wrote:

> linux-tdep.c:dump_mapping_p uses target_read_string, but in a way that
> does not really make sense.  It's better to use target_read_memory
> here.

Thanks for catching this problem, Tom.

> gdb/ChangeLog
> 2020-06-02  Tom Tromey  <tromey@adacore.com>
>
> 	* linux-tdep.c (dump_mapping_p): Use target_read_memory.
> ---
>  gdb/ChangeLog    |  4 ++++
>  gdb/linux-tdep.c | 12 +++---------
>  gdb/target.c     |  1 +
>  3 files changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
> index 0f9559355f1..2dcdc630769 100644
> --- a/gdb/linux-tdep.c
> +++ b/gdb/linux-tdep.c
> @@ -701,22 +701,16 @@ dump_mapping_p (filter_flags filterflags, const struct smaps_vmflags *v,
>    if (!dump_p && private_p && offset == 0
>        && (filterflags & COREFILTER_ELF_HEADERS) != 0)
>      {
> -      /* Let's check if we have an ELF header.  */
> -      gdb::unique_xmalloc_ptr<char> header;
> -      int errcode;
> -
>        /* Useful define specifying the size of the ELF magical
>  	 header.  */
>  #ifndef SELFMAG
>  #define SELFMAG 4
>  #endif
>  
> -      /* Read the first SELFMAG bytes and check if it is ELFMAG.  */
> -      if (target_read_string (addr, &header, SELFMAG, &errcode) == SELFMAG
> -	  && errcode == 0)
> +      /* Let's check if we have an ELF header.  */
> +      gdb_byte h[SELFMAG];
> +      if (target_read_memory (addr, h, SELFMAG) == 0)
>  	{
> -	  const char *h = header.get ();
> -
>  	  /* The EI_MAG* and ELFMAG* constants come from
>  	     <elf/common.h>.  */
>  	  if (h[EI_MAG0] == ELFMAG0 && h[EI_MAG1] == ELFMAG1

This looks OK to me.

> diff --git a/gdb/target.c b/gdb/target.c
> index 14c494688e0..897b8fdd32b 100644
> --- a/gdb/target.c
> +++ b/gdb/target.c
> @@ -50,6 +50,7 @@
>  #include "terminal.h"
>  #include <unordered_map>
>  #include "target-connection.h"
> +#include "valprint.h"
>  
>  static void generic_tls_error (void) ATTRIBUTE_NORETURN;

This hunk looks unrelated.

Thanks,

-- 
Sergio
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