proot: Properly handle relocated embedded loader

The _binary_loader_exe_size variable can be relocated by Android linker
which makes it unusable, rely instead on end-start which can be
relocated

Also don't reject binaries with linker having it's own DT_INTERP section
(like /system/bin/linker on ARM Android)

diff --git a/disabled-packages/proot/src-execve-enter.c.patch b/disabled-packages/proot/src-execve-enter.c.patch
new file mode 100644 (file)
index 0000000..6b77fc8
--- /dev/null
+++ b/disabled-packages/proot/src-execve-enter.c.patch
@@ -0,0 +1,42 @@
+--- PRoot-5.1.0/src/execve/enter.c     2014-12-15 15:18:11.000000000 +0100
++++ src/src/execve/enter.c     2016-03-20 12:05:08.013426156 +0100
+@@ -454,10 +454,10 @@
+ }
+ 
+ extern unsigned char _binary_loader_exe_start;
+-extern unsigned char _binary_loader_exe_size;
++extern unsigned char _binary_loader_exe_end;
+ 
+ extern unsigned char WEAK _binary_loader_m32_exe_start;
+-extern unsigned char WEAK _binary_loader_m32_exe_size;
++extern unsigned char WEAK _binary_loader_m32_exe_end;
+ 
+ /**
+  * Extract the built-in loader.  This function returns NULL if an
+@@ -483,11 +483,11 @@
+ 
+       if (wants_32bit_version) {
+               start = (void *) &_binary_loader_m32_exe_start;
+-              size  = (size_t) &_binary_loader_m32_exe_size;
++              size  = (size_t) (&_binary_loader_m32_exe_end - &_binary_loader_m32_exe_start);
+       }
+       else {
+               start = (void *) &_binary_loader_exe_start;
+-              size  = (size_t) &_binary_loader_exe_size;
++              size  = (size_t) (&_binary_loader_exe_end - &_binary_loader_exe_start);
+       }
+ 
+       status2 = write(fd, start, size);
+@@ -645,8 +645,10 @@
+ 
+               /* An ELF interpreter is supposed to be
+                * standalone.  */
+-              if (tracee->load_info->interp->interp != NULL)
+-                      return -EINVAL;
++              if (tracee->load_info->interp->interp != NULL) {
++                      TALLOC_FREE(tracee->load_info->interp->interp);
++                      // TODO: Print warning?
++              }
+       }
+ 
+       compute_load_addresses(tracee);