src-test2/libexec/rtld-elf/arm/rtld_start.S, branch master FreeBSD source tree https://cgit-dev.freebsd.org/src-test2/atom?h=master 2015-09-29T16:09:58Z Annotate arm userspace assembler sources stating their tolerance to 2015-09-29T16:09:58Z Konstantin Belousov kib@FreeBSD.org 2015-09-29T16:09:58Z urn:sha1:96cdb0ab9d6d89d47c14f239933391a1f7d465c7 the non-executable stack. Reviewed by: andrew Sponsored by: The FreeBSD Foundation Align the stack in _rtld_bind_start. Normally this is called with the 2014-07-06T10:24:06Z Andrew Turner andrew@FreeBSD.org 2014-07-06T10:24:06Z urn:sha1:0685d955d6c6218db44bb9a67f945decf3470ea4 correct stack alignment, however when we have a leaf function that uses thread local storage it calls __aeabi_read_tp to get the thread pointer. Neither GCC or clang see this as a function call so will align the stack to a 4-byte boundary. This may be a problem as _rtld_bind expects to be on an 8-byte boundary. The solution is to store a copy of the stack pointer and force the alignment before calling _rtld_bind. This fixes a problem with armeb where applications would crash in odd ways. It should also remove the need for a local patch to clang to force the stack alignment to an 8-byte boundary, even for leaf functions. Further testing will be needed before reverting this local change to clang as we may rely on it in other places. Reviewed by: jmg@ Ensure we align the stack to 8 bytes in rtld. 2012-08-04T05:30:20Z Andrew Turner andrew@FreeBSD.org 2012-08-04T05:30:20Z urn:sha1:782b05f96b15a2d92336dd0bd8fc06dbc4638312 This is not strictly required with the current ABI but will be when we switch to the ARM EABI. The aapcs requires the stack to be 4 byte aligned at all times and 8 byte aligned when calling a public subroutine where the current ABI only requires sp to be a multiple of 4. The NetBSD Foundation has granted permission to remove clauses 3 and 4. 2010-02-16T21:49:36Z Warner Losh imp@FreeBSD.org 2010-02-16T21:49:36Z urn:sha1:6f76ed8008a7bf64cfa7da066b8d05644f87b51d Obtained from: NetBSD Use add instead of saving the sp in a register. 2004-09-28T14:41:15Z Olivier Houchard cognet@FreeBSD.org 2004-09-28T14:41:15Z urn:sha1:0e030636cb7bb69285ec77ecc46b87b49cdca96d Add stubs for TLS. 2004-09-23T23:04:52Z Olivier Houchard cognet@FreeBSD.org 2004-09-23T23:04:52Z urn:sha1:9ac88d19dcd10177f5580fa806ae0bab8005f836 Arbitraly choose the 2nd variant until I figure out which one I should use. Import arm bits for rtld-elf. 2004-05-14T12:15:51Z Olivier Houchard cognet@FreeBSD.org 2004-05-14T12:15:51Z urn:sha1:e659267f1e22c5b9c79bae499bbc95b183b9aae2 Obtained from: NetBSD