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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-09-28 15:28:00 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-09-28 15:28:12 -0700 |
| commit | 4088d8dd29ce0629eeaa7cceca02414c85d98e05 (patch) | |
| tree | 0b807276e1826b3c4522721d076aa81c23c5da8b | |
| parent | 4d3693ec1cb7d247a217dc1eb7121c658f818dca (diff) | |
| download | glibc-4088d8dd29ce0629eeaa7cceca02414c85d98e05.tar.gz glibc-4088d8dd29ce0629eeaa7cceca02414c85d98e05.tar.xz glibc-4088d8dd29ce0629eeaa7cceca02414c85d98e05.zip | |
x86: Allow undefined _DYNAMIC in static executable
When --enable-static-pie is used to build static PIE, _DYNAMIC is used to compute the load address of static PIE. But _DYNAMIC is undefined when creating static executable. This patch makes _DYNAMIC weak in PIE libc.a so that it can be undefined. * sysdeps/i386/dl-machine.h (elf_machine_load_address): Allow undefined _DYNAMIC in PIE libc.a. * sysdeps/x86_64/dl-machine.h (elf_machine_load_address): Likewse.
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | sysdeps/i386/dl-machine.h | 11 | ||||
| -rw-r--r-- | sysdeps/x86_64/dl-machine.h | 11 |
3 files changed, 25 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog index e4919f2f38..1171915738 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2017-09-28 H.J. Lu <hongjiu.lu@intel.com> + + * sysdeps/i386/dl-machine.h (elf_machine_load_address): Allow + undefined _DYNAMIC in PIE libc.a. + * sysdeps/x86_64/dl-machine.h (elf_machine_load_address): + Likewse. + 2017-09-28 Wilco Dijkstra <wdijkstr@arm.com> * sysdeps/alpha/fpu/bits/mathinline.h: Delete file. diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 2e17eba5c0..242c692c17 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -54,8 +54,15 @@ elf_machine_load_address (void) /* Compute the difference between the runtime address of _DYNAMIC as seen by a GOTOFF reference, and the link-time address found in the special unrelocated first GOT entry. */ - extern Elf32_Dyn bygotoff[] asm ("_DYNAMIC") attribute_hidden; - return (Elf32_Addr) &bygotoff - elf_machine_dynamic (); +#ifndef SHARED + extern Elf32_Dyn _DYNAMIC[] __attribute__((weak, visibility ("hidden"))); + if (!_DYNAMIC) + return 0; +#endif + /* The address of dynamic must be taken as non-weak to avoid dynamic + relocation. */ + extern Elf32_Dyn dynamic[] asm ("_DYNAMIC") attribute_hidden; + return (Elf32_Addr) &dynamic - elf_machine_dynamic (); } /* Set up the loaded object described by L so its unrelocated PLT diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h index 6a04cbcdc9..a79e5ca2f9 100644 --- a/sysdeps/x86_64/dl-machine.h +++ b/sysdeps/x86_64/dl-machine.h @@ -55,8 +55,15 @@ elf_machine_load_address (void) /* Compute the difference between the runtime address of _DYNAMIC as seen by an IP-relative reference, and the link-time address found in the special unrelocated first GOT entry. */ - extern ElfW(Dyn) _DYNAMIC[] attribute_hidden; - return (ElfW(Addr)) &_DYNAMIC - elf_machine_dynamic (); +#ifndef SHARED + extern ElfW(Dyn) _DYNAMIC[] __attribute__((weak, visibility ("hidden"))); + if (!_DYNAMIC) + return 0; +#endif + /* The address of dynamic must be taken as non-weak to avoid dynamic + relocation. */ + extern ElfW(Dyn) dynamic[] asm ("_DYNAMIC") attribute_hidden; + return (ElfW(Addr)) &dynamic - elf_machine_dynamic (); } /* Set up the loaded object described by L so its unrelocated PLT |