From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address.patch added to -mm tree Date: Tue, 08 Nov 2016 14:07:37 -0800 Message-ID: <58224ca9.Z1eVmCSqZPNdHE33%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46354 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750724AbcKHWHj (ORCPT ); Tue, 8 Nov 2016 17:07:39 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: bhe@redhat.com, anderson@redhat.com, ats-kumagai@wm.jp.nec.com, d.hatayama@jp.fujitsu.com, dyoung@redhat.com, ebiederm@xmission.com, hpa@zytor.com, keescook@chromium.org, mingo@redhat.com, panand@redhat.com, surovegin@google.com, takahiro.akashi@linaro.org, tglx@linutronix.de, thgarnie@google.com, vgoyal@redhat.com, xlpang@redhat.com, mm-commits@vger.kernel.org The patch titled Subject: kexec: export the value of phys_base instead of symbol address has been added to the -mm tree. Its filename is kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Baoquan He Subject: kexec: export the value of phys_base instead of symbol address Currently in x86_64, the symbol address of phys_base is exported to vmcoreinfo. Dave Anderson complained this is really useless for his Crash implementation. Because in user-space utility Crash and Makedumpfile which exported vmcore information is mainly used for, value of phys_base is needed to covert virtual address of exported kernel symbol to physical address. Especially init_level4_pgt, if we want to access and go over the page table to look up a PA corresponding to VA, firstly we need calculate page_dir = SYMBOL(init_level4_pgt) - __START_KERNEL_map + phys_base; Now in Crash and Makedumpfile, we have to analyze the vmcore elf program header to get value of phys_base. As Dave said, it would be preferable if it were readily availabl in vmcoreinfo rather than depending upon the PT_LOAD semantics. Hence in this patch change to export the value of phys_base instead of its virtual address. And people also complained that KERNEL_IMAGE_SIZE exporting is x86_64 only, should be moved into arch dependent function arch_crash_save_vmcoreinfo. Do the moving in this patch. Link: http://lkml.kernel.org/r/1478568596-30060-2-git-send-email-bhe@redhat.com Signed-off-by: Baoquan He Cc: Thomas Garnier Cc: Baoquan He Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H . Peter Anvin" Cc: Eric Biederman Cc: Xunlei Pang Cc: HATAYAMA Daisuke Cc: Kees Cook Cc: Eugene Surovegin Cc: Dave Young Cc: AKASHI Takahiro Cc: Atsushi Kumagai Cc: Dave Anderson Cc: Pratyush Anand Cc: Vivek Goyal Signed-off-by: Andrew Morton --- arch/x86/kernel/machine_kexec_64.c | 3 ++- kernel/kexec_core.c | 3 --- 2 files changed, 2 insertions(+), 4 deletions(-) diff -puN arch/x86/kernel/machine_kexec_64.c~kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address arch/x86/kernel/machine_kexec_64.c --- a/arch/x86/kernel/machine_kexec_64.c~kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address +++ a/arch/x86/kernel/machine_kexec_64.c @@ -328,7 +328,7 @@ void machine_kexec(struct kimage *image) void arch_crash_save_vmcoreinfo(void) { - VMCOREINFO_SYMBOL(phys_base); + VMCOREINFO_NUMBER(phys_base); VMCOREINFO_SYMBOL(init_level4_pgt); #ifdef CONFIG_NUMA @@ -337,6 +337,7 @@ void arch_crash_save_vmcoreinfo(void) #endif vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); + VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE); } /* arch-dependent functionality related to kexec file-based syscall */ diff -puN kernel/kexec_core.c~kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address kernel/kexec_core.c --- a/kernel/kexec_core.c~kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address +++ a/kernel/kexec_core.c @@ -1467,9 +1467,6 @@ static int __init crash_save_vmcoreinfo_ #endif VMCOREINFO_NUMBER(PG_head_mask); VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); -#ifdef CONFIG_X86 - VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE); -#endif #ifdef CONFIG_HUGETLB_PAGE VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); #endif _ Patches currently in -mm which might be from bhe@redhat.com are revert-kdump-vmcoreinfo-report-memory-sections-virtual-addresses.patch kexec-change-to-export-the-value-of-phys_base-instead-of-symbol-address.patch