{"id":2293,"date":"2018-05-07T19:00:20","date_gmt":"2018-05-08T02:00:20","guid":{"rendered":"http:\/\/rglinuxtech.com\/?p=2293"},"modified":"2018-05-07T19:00:20","modified_gmt":"2018-05-08T02:00:20","slug":"gcc-update-to-8-1-1-still-gives-kernel-compile-warnings","status":"publish","type":"post","link":"https:\/\/rglinuxtech.com\/?p=2293","title":{"rendered":"GCC &#8211; Update to 8.1.1 &#8211; Still Gives Kernel Compile Warnings.."},"content":{"rendered":"<p>Fedora 28 has <strong>GCC 8.1.1<\/strong> available (currently in &#8216;<em>updates-testing<\/em>&#8216; repo), and I tested this with Kernel <strong>4.17-rc4<\/strong>, to see if there was any improvement in the horde of warnings generated with 8.0.1.<\/p>\n<p>In short, there is no real difference:<\/p>\n<pre><strong><span style=\"font-family: courier\\ new, courier;\">....................................<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\"> CC security\/keys\/request_key.o<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_lapic_reg_read()+0x126: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: limit_periodic_timer_frequency.part.16()+0x3b: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_irq_delivery_to_apic_fast()+0x373: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_intr_is_single_vcpu_fast()+0x286: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_lapic_set_base()+0xf0: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_create_lapic()+0x39: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_lapic_set_base.cold.24()+0x16: sibling call from callable instruction with modified stack frame<\/span><\/strong>\r\n<strong><span style=\"font-family: courier\\ new, courier;\">..................... etc, etc....................<\/span><\/strong><\/pre>\n<p>There were patches proposed for the kernel, for GCC 8, but these would not appear to have made it into mainstream, yet..\u00a0\u00a0\u00a0 There may be some debate over whether the fix is with GCC, or with kernel code&#8230;\u00a0\u00a0 Older versions of the kernel (tested with 4.9.98) compile more &#8216;cleanly&#8217;..<\/p>\n<p><em>Robert Gadsdon.\u00a0\u00a0\u00a0 May 7th, 2018.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Fedora 28 has GCC 8.1.1 available (currently in &#8216;updates-testing&#8216; repo), and I tested this with Kernel 4.17-rc4, to see if there was any improvement in the horde of warnings generated with 8.0.1. In short, there is no real difference: &#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230; CC security\/keys\/request_key.o arch\/x86\/kvm\/lapic.o: warning: objtool: kvm_lapic_reg_read()+0x126: sibling call from callable instruction with modified stack frame arch\/x86\/kvm\/lapic.o: warning: <span class=\"excerpt-dots\">&hellip;<\/span> <a class=\"more-link\" href=\"https:\/\/rglinuxtech.com\/?p=2293\"><span class=\"more-msg\">Continue reading &rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[5,10,1617,14,15,19,20],"tags":[1841,1878,1879,1881,1880],"class_list":["post-2293","post","type-post","status-publish","format-standard","hentry","category-compilation","category-fedora","category-gcc","category-kernel","category-linux-2","category-opinion","category-performance-2","tag-fedora-28","tag-gcc-8-1-1","tag-kernel-4-17-rc4","tag-objtool","tag-still-multiple-warnings"],"_links":{"self":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts\/2293","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2293"}],"version-history":[{"count":1,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts\/2293\/revisions"}],"predecessor-version":[{"id":2294,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts\/2293\/revisions\/2294"}],"wp:attachment":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2293"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2293"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2293"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}