Date: Fri, 17 Jan 2020 23:41:36 +0000 (UTC) From: Brandon Bergren <bdragon@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r356856 - head/sys/powerpc/powerpc Message-ID: <202001172341.00HNfaRw095049@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: bdragon Date: Fri Jan 17 23:41:35 2020 New Revision: 356856 URL: https://svnweb.freebsd.org/changeset/base/356856 Log: [PowerPC] Save a dword in the powerpc64 signal trampoline In r291668, an instruction was added to sigcode64.S without the nop pad at the end being taken out. Due to alignment, this means that a dword is being wasted on the shared page for no reason. Take out this nop, and add some comments while I'm here. Reviewed by: jhibbits Sponsored by: Tag1 Consulting, Inc. Differential Revision: https://reviews.freebsd.org/D23055 Modified: head/sys/powerpc/powerpc/sigcode64.S Modified: head/sys/powerpc/powerpc/sigcode64.S ============================================================================== --- head/sys/powerpc/powerpc/sigcode64.S Fri Jan 17 22:26:41 2020 (r356855) +++ head/sys/powerpc/powerpc/sigcode64.S Fri Jan 17 23:41:35 2020 (r356856) @@ -63,9 +63,13 @@ CNAME(sigcode64_elfv2): addi 3,1,112+SF_UC /* restore sp, and get &frame->sf_uc */ li 0,SYS_sigreturn sc /* sigreturn(scp) */ + /* + * If we get back to here, it means sigreturn failed. + * As such, we are now stuck in the wrong context. + * Exit immediately without touching the stack. + */ li 0,SYS_exit sc /* exit(errno) */ - nop /* align to doubleword */ endsigcode64: .data
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202001172341.00HNfaRw095049>