[Lldb-commits] [PATCH] D11465: Fix "process load/unload" on android

[Greg Clayton via Phabricator via lldb-commits]

clayborg added a comment.

It would be nice to auto detect the names correctly?



================
Comment at: lldb/trunk/source/Plugins/Platform/Android/PlatformAndroid.cpp:389
+                   struct __lldb_dlopen_result { void *image_ptr; const char *error_str; } the_result;
+                   the_result.image_ptr = __dl_dlopen ("%s", 2);
+                   if (the_result.image_ptr == (void*)0x0)
----------------
labath wrote:
> nitesh.jain wrote:
> > Hi Tamas,
> > 
> > When I run "process load libloadunload_a.so --install" its fail with error Couldn't lookup symbols: __dl_dlerror, __dl_dlopen.  
> > 
> > Symbol table contains 13 entries:
> >    Num:    Value  Size Type    Bind   Vis      Ndx Name
> >      0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
> >      1: 00000304     5 FUNC    GLOBAL DEFAULT    5 android_dlopen_ext
> >      2: 00000309     5 FUNC    GLOBAL DEFAULT    5 android_get_LD_LIBRARY_PA
> >      3: 0000030e     5 FUNC    GLOBAL DEFAULT    5 android_update_LD_LIBRARY
> >      4: 00000313     5 FUNC    GLOBAL DEFAULT    5 dl_iterate_phdr
> >      5: 00000318     5 FUNC    GLOBAL DEFAULT    5 **dladdr**
> >      6: 0000031d     5 FUNC    GLOBAL DEFAULT    5 **dlclose**
> >      7: 00000322     5 FUNC    GLOBAL DEFAULT    5 **dlerror**
> >      8: 00000327     5 FUNC    GLOBAL DEFAULT    5 **dlopen**
> >      9: 0000032c     5 FUNC    GLOBAL DEFAULT    5 dlsym
> >     10: 00002000     0 NOTYPE  GLOBAL DEFAULT  ABS _edata
> >     11: 00002000     0 NOTYPE  GLOBAL DEFAULT  ABS __bss_start
> >     12: 00002000     0 NOTYPE  GLOBAL DEFAULT  ABS _end
> > 
> > The symbols are not prefix with "__dl_" . We are using SDK version 25 for MIP64r6 target. 
> > 
> > generic_mips64:/ # getprop ro.build.version.sdk
> > 25
> > 
> > Even we are not seeing prefix "__dl_" added to X86-64 dynamic symbol
> > Symbol table '.dynsym' contains 12 entries:
> >    Num:    Value          Size Type    Bind   Vis      Ndx Name
> >      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
> >      1: 0000000000000442     6 FUNC    GLOBAL DEFAULT    7 dl_iterate_phdr@@LIBC
> >      2: 000000000000043c     6 FUNC    GLOBAL DEFAULT    7 android_dlopen_ext@@LIBC
> >      3: 000000000000044e     6 FUNC    GLOBAL DEFAULT    7 dlclose@@LIBC
> >      4: 0000000000000448     6 FUNC    GLOBAL DEFAULT    7 dladdr@@LIBC
> >      5: 000000000000045a     6 FUNC    GLOBAL DEFAULT    7 dlopen@@LIBC
> >      6: 0000000000000454     6 FUNC    GLOBAL DEFAULT    7 dlerror@@LIBC
> >      7: 0000000000000460     6 FUNC    GLOBAL DEFAULT    7 dlsym@@LIBC
> >      8: 0000000000002000     0 NOTYPE  GLOBAL DEFAULT  ABS _edata
> >      9: 0000000000002000     0 NOTYPE  GLOBAL DEFAULT  ABS __bss_start
> >     10: 0000000000002000     0 NOTYPE  GLOBAL DEFAULT  ABS _end
> >     11: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LIBC
> > 
> > Symbol table '.symtab' contains 14 entries:
> >    Num:    Value          Size Type    Bind   Vis      Ndx Name
> >      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
> >      1: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS tmp-platform.c
> >      2: 0000000000001ee0   288 OBJECT  LOCAL  HIDDEN    10 _DYNAMIC
> >      3: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LIBC
> >      4: 0000000000000442     6 FUNC    GLOBAL DEFAULT    7 dl_iterate_phdr
> >      5: 000000000000043c     6 FUNC    GLOBAL DEFAULT    7 android_dlopen_ext
> >      6: 000000000000044e     6 FUNC    GLOBAL DEFAULT    7 dlclose
> >      7: 0000000000000448     6 FUNC    GLOBAL DEFAULT    7 dladdr
> >      8: 000000000000045a     6 FUNC    GLOBAL DEFAULT    7 dlopen
> > 
> Is it possible you are using a **preview** version of android sdk? These had the new dlopen symbols even though the official android sdk's still used the __dl_dlopen symbols?
Maybe search for a symbol named "__dl_open" first, then fall back to "dl_open" if that symbol is available, and supply as an argument for "expr.Printf(" by adding a "%s" in place of the "__dl_dlopen? call? Then it can work for both?

```
const char *dl_open_func_name = nullptr;
SymbolContextList matching_symbols;
std::vector<const char *> dl_open_names = { "__dl_open", "dl_open" };
const char *dl_open_name = nullptr;
for (auto name: dl_open_names) {
  if (process->GetTarget().GetImages().FindFunctionSymbols(ConstString(name), eFunctionNameTypeFull, matching_symbols))
    dl_open_name = name;
    break;
  }
}
```



Repository:
  rL LLVM

https://reviews.llvm.org/D11465