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| author | Nick Clifton <nickc@redhat.com> | 2014-08-20 16:10:29 +0100 |
|---|---|---|
| committer | Nick Clifton <nickc@redhat.com> | 2014-08-20 16:10:29 +0100 |
| commit | 2d5c3743a3a223dc6467ff022124b4f2f1844c91 (patch) | |
| tree | c8d626b5afab0f3a57911c01e6c5194ed7247310 /ld/emultempl | |
| parent | d36430db79dc8eccb9cb188e1234f7ff044f79b4 (diff) | |
| download | gdb-2d5c3743a3a223dc6467ff022124b4f2f1844c91.zip gdb-2d5c3743a3a223dc6467ff022124b4f2f1844c91.tar.gz gdb-2d5c3743a3a223dc6467ff022124b4f2f1844c91.tar.bz2 | |
Enabling the HIGH_ENTROPY_VA flag allows the operating system to use
addresses outside of the 32-bit range before memory exhaustion. This
results in a higher entropy implementation of ASLR when used with the
DYNAMIC_BASE flag.
* include/coff/pe.h: Add HIGH_ENTROPY_VA flag
* ld/emultempl/pep.em: Add --high-entropy-va switch
* ld/ld.texinfo: Document the --high-entropy-va switch
Diffstat (limited to 'ld/emultempl')
| -rw-r--r-- | ld/emultempl/pep.em | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em index 916a786..6d56bc3 100644 --- a/ld/emultempl/pep.em +++ b/ld/emultempl/pep.em @@ -237,6 +237,7 @@ enum options OPTION_LEADING_UNDERSCORE, OPTION_ENABLE_LONG_SECTION_NAMES, OPTION_DISABLE_LONG_SECTION_NAMES, + OPTION_HIGH_ENTROPY_VA, OPTION_DYNAMIC_BASE, OPTION_FORCE_INTEGRITY, OPTION_NX_COMPAT, @@ -314,6 +315,7 @@ gld${EMULATION_NAME}_add_options #endif {"enable-long-section-names", no_argument, NULL, OPTION_ENABLE_LONG_SECTION_NAMES}, {"disable-long-section-names", no_argument, NULL, OPTION_DISABLE_LONG_SECTION_NAMES}, + {"high-entropy-va", no_argument, NULL, OPTION_HIGH_ENTROPY_VA}, {"dynamicbase",no_argument, NULL, OPTION_DYNAMIC_BASE}, {"forceinteg", no_argument, NULL, OPTION_FORCE_INTEGRITY}, {"nxcompat", no_argument, NULL, OPTION_NX_COMPAT}, @@ -450,6 +452,8 @@ gld_${EMULATION_NAME}_list_options (FILE *file) executable image files\n")); fprintf (file, _(" --disable-long-section-names Never use long COFF section names, even\n\ in object files\n")); + fprintf (file, _(" --high-entropy-va Image is compatible with 64-bit address space\n\ + layout randomization (ASLR)\n")); fprintf (file, _(" --dynamicbase Image base address may be relocated using\n\ address space layout randomization (ASLR)\n")); fprintf (file, _(" --forceinteg Code integrity checks are enforced\n")); @@ -804,6 +808,9 @@ gld${EMULATION_NAME}_handle_option (int optc) pep_use_coff_long_section_names = 0; break; /* Get DLLCharacteristics bits */ + case OPTION_HIGH_ENTROPY_VA: + pe_dll_characteristics |= IMAGE_DLL_CHARACTERISTICS_HIGH_ENTROPY_VA; + break; case OPTION_DYNAMIC_BASE: pe_dll_characteristics |= IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE; break; |