From: H.J. Lu Date: Fri, 4 Mar 2016 23:28:59 +0000 (-0800) Subject: Replace @PLT with @GOTPCREL(%rip) in call X-Git-Tag: glibc-2.24~521 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=21683b5a7d9b8460e120e061f66a6ad84fa47e98;p=thirdparty%2Fglibc.git Replace @PLT with @GOTPCREL(%rip) in call Since __libc_start_main is called very early, lazy binding isn't relevant here. Use indirect branch via GOT to avoid extra branch to PLT slot. [BZ #19745] * sysdeps/x86_64/start.S (_start): __libc_start_main@PLT with *__libc_start_main@GOTPCREL(%rip) in call. --- diff --git a/ChangeLog b/ChangeLog index 143d4a65bcf..af555291a9a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2016-03-04 H.J. Lu + + [BZ #19745] + * sysdeps/x86_64/start.S (_start): Replace __libc_start_main@PLT + with *__libc_start_main@GOTPCREL(%rip) in call. + 2016-03-04 Roland McGrath * Makefile (tests-special): Add $(objpfx)c++-types-check.out only diff --git a/sysdeps/x86_64/start.S b/sysdeps/x86_64/start.S index 1374974307b..2369b69ec35 100644 --- a/sysdeps/x86_64/start.S +++ b/sysdeps/x86_64/start.S @@ -104,8 +104,10 @@ ENTRY (_start) mov main@GOTPCREL(%rip), %RDI_LP /* Call the user's main function, and exit with its value. - But let the libc call main. */ - call __libc_start_main@PLT + But let the libc call main. Since __libc_start_main is + called very early, lazy binding isn't relevant here. Use + indirect branch via GOT to avoid extra branch to PLT slot. */ + call *__libc_start_main@GOTPCREL(%rip) #else /* Pass address of our own entry points to .fini and .init. */ mov $__libc_csu_fini, %R8_LP