qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
* [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe
@ 2009-01-19 15:30 Riku Voipio
  2009-01-19 15:57 ` Paul Brook
  0 siblings, 1 reply; 5+ messages in thread
From: Riku Voipio @ 2009-01-19 15:30 UTC (permalink / raw)
  To: qemu-devel

Some applications like to test /proc/self/exe to find
out who they are. Fake the result of readlink() for
them.

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
---
 linux-user/main.c    |    3 +++
 linux-user/qemu.h    |    1 +
 linux-user/syscall.c |    9 +++++++--
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 3019f33..2ffe244 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -34,6 +34,8 @@
 
 #define DEBUG_LOGFILE "/tmp/qemu.log"
 
+char *exec_path;
+
 static const char *interp_prefix = CONFIG_QEMU_PREFIX;
 const char *qemu_uname_release = CONFIG_UNAME_RELEASE;
 
@@ -2314,6 +2316,7 @@ int main(int argc, char **argv, char **envp)
     if (optind >= argc)
         usage();
     filename = argv[optind];
+    exec_path = argv[optind];
 
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 9fddd05..4137567 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -120,6 +120,7 @@ typedef struct TaskState {
     uint8_t stack[0];
 } __attribute__((aligned(16))) TaskState;
 
+extern char *exec_path;
 void init_task_state(TaskState *ts);
 extern const char *qemu_uname_release;
 
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index adb27de..53167e9 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4720,8 +4720,13 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             p2 = lock_user(VERIFY_WRITE, arg2, arg3, 0);
             if (!p || !p2)
                 ret = -TARGET_EFAULT;
-            else
-                ret = get_errno(readlink(path(p), p2, arg3));
+            else {
+                if (strncmp((const char *)p, "/proc/self/exe", 14) == 0)
+                    ret = get_errno(snprintf((char *)p2, arg3, "%s", exec_path));
+                else
+                    ret = get_errno(readlink(path(p), p2, arg3));
+                break;
+            }
             unlock_user(p2, arg2, ret);
             unlock_user(p, arg1, 0);
         }
-- 
1.5.6.5


-- 
"rm -rf" only sounds scary if you don't have backups

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe
  2009-01-19 15:30 [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe Riku Voipio
@ 2009-01-19 15:57 ` Paul Brook
  2009-01-20 16:01   ` Riku Voipio
  0 siblings, 1 reply; 5+ messages in thread
From: Paul Brook @ 2009-01-19 15:57 UTC (permalink / raw)
  To: qemu-devel; +Cc: Riku Voipio

On Monday 19 January 2009, Riku Voipio wrote:
> Some applications like to test /proc/self/exe to find
> out who they are. Fake the result of readlink() for
> them.

> +    exec_path = argv[optind];

Won't this give the wrong answer when the binary is invoked using a relative 
path or a symlink? On my system /proc/self/exe is always an absolute path to 
an actual file.

Paul

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe
  2009-01-19 15:57 ` Paul Brook
@ 2009-01-20 16:01   ` Riku Voipio
  2009-01-26 19:07     ` Riku Voipio
  0 siblings, 1 reply; 5+ messages in thread
From: Riku Voipio @ 2009-01-20 16:01 UTC (permalink / raw)
  To: qemu-devel

[-- Attachment #1: Type: text/plain, Size: 565 bytes --]

On Mon, Jan 19, 2009 at 03:57:26PM +0000, Paul Brook wrote:
> On Monday 19 January 2009, Riku Voipio wrote:
> > Some applications like to test /proc/self/exe to find
> > out who they are. Fake the result of readlink() for
> > them.
> 
> > +    exec_path = argv[optind];

> Won't this give the wrong answer when the binary is invoked using a relative 
> path or a symlink? On my system /proc/self/exe is always an absolute path to 
> an actual file.

You are right. Fixed version attached.

-- 
"rm -rf" only sounds scary if you don't have backups

[-- Attachment #2: 0002-linux-user-identify-running-binary-in-proc-self-ex.patch --]
[-- Type: text/plain, Size: 2496 bytes --]

>From f3be7d8337ae3def8f2d3d4e089016fcd9686467 Mon Sep 17 00:00:00 2001
From: Riku Voipio <riku.voipio@iki.fi>
Date: Tue, 20 Jan 2009 17:46:18 +0200
Subject: [PATCH] linux-user: identify running binary in /proc/self/exe

Some applications like to test /proc/self/exe to find
out who they are. Fake the result of readlink() for
them. Use realpath() to return full path to binary
(which the links /proc/self/exe are)

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
---
 linux-user/main.c    |    3 +++
 linux-user/qemu.h    |    1 +
 linux-user/syscall.c |   12 ++++++++++--
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 59da5fd..b45dcfe 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -34,6 +34,8 @@
 
 #define DEBUG_LOGFILE "/tmp/qemu.log"
 
+char *exec_path;
+
 static const char *interp_prefix = CONFIG_QEMU_PREFIX;
 const char *qemu_uname_release = CONFIG_UNAME_RELEASE;
 
@@ -2312,6 +2314,7 @@ int main(int argc, char **argv, char **envp)
     if (optind >= argc)
         usage();
     filename = argv[optind];
+    exec_path = argv[optind];
 
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 9fddd05..4137567 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -120,6 +120,7 @@ typedef struct TaskState {
     uint8_t stack[0];
 } __attribute__((aligned(16))) TaskState;
 
+extern char *exec_path;
 void init_task_state(TaskState *ts);
 extern const char *qemu_uname_release;
 
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 5d787bb..21ec17b 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4375,8 +4375,16 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             p2 = lock_user(VERIFY_WRITE, arg2, arg3, 0);
             if (!p || !p2)
                 ret = -TARGET_EFAULT;
-            else
-                ret = get_errno(readlink(path(p), p2, arg3));
+            else {
+                if (strncmp((const char *)p, "/proc/self/exe", 14) == 0) {
+                    char real[PATH_MAX];
+                    ret = get_errno(realpath(exec_path,real));
+                    snprintf((char *)p2, arg3, "%s", real);
+                    }
+                else
+                    ret = get_errno(readlink(path(p), p2, arg3));
+                break;
+            }
             unlock_user(p2, arg2, ret);
             unlock_user(p, arg1, 0);
         }
-- 
1.5.6.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe
  2009-01-20 16:01   ` Riku Voipio
@ 2009-01-26 19:07     ` Riku Voipio
  2009-01-30 20:10       ` Aurelien Jarno
  0 siblings, 1 reply; 5+ messages in thread
From: Riku Voipio @ 2009-01-26 19:07 UTC (permalink / raw)
  To: qemu-devel

Some applications like to test /proc/self/exe to find
out who they are. Fake the result of readlink() for
them. Use realpath() to return full path to binary
(which the links /proc/self/exe are)

updated version - fix ret/errno in the /proc/self/exe case.

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
---
 linux-user/main.c    |    3 +++
 linux-user/qemu.h    |    1 +
 linux-user/syscall.c |   15 ++++++++++++---
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index cb10173..3418ca6 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -37,6 +37,8 @@
 
 #define DEBUG_LOGFILE "/tmp/qemu.log"
 
+char *exec_path;
+
 static const char *interp_prefix = CONFIG_QEMU_PREFIX;
 const char *qemu_uname_release = CONFIG_UNAME_RELEASE;
 
@@ -2354,6 +2356,7 @@ int main(int argc, char **argv, char **envp)
     if (optind >= argc)
         usage();
     filename = argv[optind];
+    exec_path = argv[optind];
 
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 9fddd05..4137567 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -120,6 +120,7 @@ typedef struct TaskState {
     uint8_t stack[0];
 } __attribute__((aligned(16))) TaskState;
 
+extern char *exec_path;
 void init_task_state(TaskState *ts);
 extern const char *qemu_uname_release;
 
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 690df14..2903bf3 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4877,13 +4877,22 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #endif
     case TARGET_NR_readlink:
         {
-            void *p2;
+            void *p2, *temp;
             p = lock_user_string(arg1);
             p2 = lock_user(VERIFY_WRITE, arg2, arg3, 0);
             if (!p || !p2)
                 ret = -TARGET_EFAULT;
-            else
-                ret = get_errno(readlink(path(p), p2, arg3));
+            else {
+                if (strncmp((const char *)p, "/proc/self/exe", 14) == 0) {
+                    char real[PATH_MAX];
+                    temp = realpath(exec_path,real);
+                    ret = (temp==NULL) ? get_errno(-1) : strlen(real) ;
+                    snprintf((char *)p2, arg3, "%s", real);
+                    }
+                else
+                    ret = get_errno(readlink(path(p), p2, arg3));
+                break;
+            }
             unlock_user(p2, arg2, ret);
             unlock_user(p, arg1, 0);
         }
-- 
1.5.6.5

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe
  2009-01-26 19:07     ` Riku Voipio
@ 2009-01-30 20:10       ` Aurelien Jarno
  0 siblings, 0 replies; 5+ messages in thread
From: Aurelien Jarno @ 2009-01-30 20:10 UTC (permalink / raw)
  To: Riku Voipio; +Cc: qemu-devel

On Mon, Jan 26, 2009 at 09:07:11PM +0200, Riku Voipio wrote:
> Some applications like to test /proc/self/exe to find
> out who they are. Fake the result of readlink() for
> them. Use realpath() to return full path to binary
> (which the links /proc/self/exe are)
> 
> updated version - fix ret/errno in the /proc/self/exe case.
> 
> Signed-off-by: Riku Voipio <riku.voipio@iki.fi>

Thanks, applied.

> ---
>  linux-user/main.c    |    3 +++
>  linux-user/qemu.h    |    1 +
>  linux-user/syscall.c |   15 ++++++++++++---
>  3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/linux-user/main.c b/linux-user/main.c
> index cb10173..3418ca6 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -37,6 +37,8 @@
>  
>  #define DEBUG_LOGFILE "/tmp/qemu.log"
>  
> +char *exec_path;
> +
>  static const char *interp_prefix = CONFIG_QEMU_PREFIX;
>  const char *qemu_uname_release = CONFIG_UNAME_RELEASE;
>  
> @@ -2354,6 +2356,7 @@ int main(int argc, char **argv, char **envp)
>      if (optind >= argc)
>          usage();
>      filename = argv[optind];
> +    exec_path = argv[optind];
>  
>      /* Zero out regs */
>      memset(regs, 0, sizeof(struct target_pt_regs));
> diff --git a/linux-user/qemu.h b/linux-user/qemu.h
> index 9fddd05..4137567 100644
> --- a/linux-user/qemu.h
> +++ b/linux-user/qemu.h
> @@ -120,6 +120,7 @@ typedef struct TaskState {
>      uint8_t stack[0];
>  } __attribute__((aligned(16))) TaskState;
>  
> +extern char *exec_path;
>  void init_task_state(TaskState *ts);
>  extern const char *qemu_uname_release;
>  
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 690df14..2903bf3 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -4877,13 +4877,22 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
>  #endif
>      case TARGET_NR_readlink:
>          {
> -            void *p2;
> +            void *p2, *temp;
>              p = lock_user_string(arg1);
>              p2 = lock_user(VERIFY_WRITE, arg2, arg3, 0);
>              if (!p || !p2)
>                  ret = -TARGET_EFAULT;
> -            else
> -                ret = get_errno(readlink(path(p), p2, arg3));
> +            else {
> +                if (strncmp((const char *)p, "/proc/self/exe", 14) == 0) {
> +                    char real[PATH_MAX];
> +                    temp = realpath(exec_path,real);
> +                    ret = (temp==NULL) ? get_errno(-1) : strlen(real) ;
> +                    snprintf((char *)p2, arg3, "%s", real);
> +                    }
> +                else
> +                    ret = get_errno(readlink(path(p), p2, arg3));
> +                break;
> +            }
>              unlock_user(p2, arg2, ret);
>              unlock_user(p, arg1, 0);
>          }
> -- 
> 1.5.6.5
> 
> 
> 
> 

-- 
Aurelien Jarno	                        GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2009-01-30 20:10 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-01-19 15:30 [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/self/exe Riku Voipio
2009-01-19 15:57 ` Paul Brook
2009-01-20 16:01   ` Riku Voipio
2009-01-26 19:07     ` Riku Voipio
2009-01-30 20:10       ` Aurelien Jarno

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).