[7/7] hurd: Fix FS_RETRY_MAGICAL "machtype" handling

Message ID 20230429131354.2507443-7-bugaevc@gmail.com
State Committed, archived
Headers
Series [1/7] hurd: Simplify _hurd_critical_section_lock a bit |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

Sergey Bugaev April 29, 2023, 1:13 p.m. UTC
  We need to set file_name, not update retryname. This is what the other
branches do.

Before this change, any attempt to access such a file would segfault due
to file_name being unset:

$ settrans -ac /tmp/my-machtype /hurd/magic machtype
$ cat /tmp/my-machtype
Segmentation fault

Checked on i686-gnu.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
---
 hurd/lookup-retry.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)
  

Comments

Samuel Thibault April 29, 2023, 3:01 p.m. UTC | #1
Applied, thanks!

Sergey Bugaev, le sam. 29 avril 2023 16:13:54 +0300, a ecrit:
> We need to set file_name, not update retryname. This is what the other
> branches do.
> 
> Before this change, any attempt to access such a file would segfault due
> to file_name being unset:
> 
> $ settrans -ac /tmp/my-machtype /hurd/magic machtype
> $ cat /tmp/my-machtype
> Segmentation fault
> 
> Checked on i686-gnu.
> 
> Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
> ---
>  hurd/lookup-retry.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/hurd/lookup-retry.c b/hurd/lookup-retry.c
> index 99c98104..62f94bbc 100644
> --- a/hurd/lookup-retry.c
> +++ b/hurd/lookup-retry.c
> @@ -277,7 +277,6 @@ __hurd_file_name_lookup_retry (error_t (*use_init_port)
>  		  error_t err;
>  		  struct host_basic_info hostinfo;
>  		  mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
> -		  char *p;
>  		  /* XXX want client's host */
>  		  if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
>  					 (integer_t *) &hostinfo,
> @@ -288,13 +287,11 @@ __hurd_file_name_lookup_retry (error_t (*use_init_port)
>  		      err = EGRATUITOUS;
>  		      goto out;
>  		    }
> -		  p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
> -		  *--p = '/';
> -		  p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
> -		  if (p < retryname)
> +		  file_name = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
> +		  *--file_name = '/';
> +		  file_name = _itoa (hostinfo.cpu_type, file_name, 10, 0);
> +		  if (file_name < retryname)
>  		    abort ();	/* XXX write this right if this ever happens */
> -		  if (p > retryname)
> -		    memmove (retryname, p, strlen(p) + 1);
>  		  startdir = *result;
>  		}
>  	      else
> -- 
> 2.40.1
>
  

Patch

diff --git a/hurd/lookup-retry.c b/hurd/lookup-retry.c
index 99c98104..62f94bbc 100644
--- a/hurd/lookup-retry.c
+++ b/hurd/lookup-retry.c
@@ -277,7 +277,6 @@  __hurd_file_name_lookup_retry (error_t (*use_init_port)
 		  error_t err;
 		  struct host_basic_info hostinfo;
 		  mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
-		  char *p;
 		  /* XXX want client's host */
 		  if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
 					 (integer_t *) &hostinfo,
@@ -288,13 +287,11 @@  __hurd_file_name_lookup_retry (error_t (*use_init_port)
 		      err = EGRATUITOUS;
 		      goto out;
 		    }
-		  p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
-		  *--p = '/';
-		  p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
-		  if (p < retryname)
+		  file_name = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
+		  *--file_name = '/';
+		  file_name = _itoa (hostinfo.cpu_type, file_name, 10, 0);
+		  if (file_name < retryname)
 		    abort ();	/* XXX write this right if this ever happens */
-		  if (p > retryname)
-		    memmove (retryname, p, strlen(p) + 1);
 		  startdir = *result;
 		}
 	      else