From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Wed, 22 Jun 2016 14:59:41 +0900 Subject: [PATCH v19 10/13] arm64: kdump: add VMCOREINFO's for user-space coredump tools In-Reply-To: <20160620053222.GB14309@dhcppc9> References: <6e96110e85e7b1167043d789e85f9c916fdf281a.1466120418.git.geoff@infradead.org> <20160620053222.GB14309@dhcppc9> Message-ID: <20160622055940.GY20774@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jun 20, 2016 at 11:02:22AM +0530, Pratyush Anand wrote: > +Atsushi > > Hi Takahiro, > > On 16/06/2016:11:48:28 PM, Geoff Levand wrote: > > From: AKASHI Takahiro > > > > For the current crash utility, we need to know, at least, > > - kimage_voffset > > - PHYS_OFFSET > > to handle the contents of core dump file (/proc/vmcore) correctly due to > > the introduction of KASLR (CONFIG_RANDOMIZE_BASE) in v4.6. > > This patch puts them as VMCOREINFO's into the file. > > > > - VA_BITS > > is also added for makedumpfile command. > > Thanks for adding them. They are quite helpful for makedumpfile as well. > > > More VMCOREINFO's may be added later. > > Yes, we will need to pass VMCOREINFO_SYMBOL(_text) and VMCOREINFO_SYMBOL(_end) > in order to work with makedumpfile. I know that adding those symbols is the easiest way, but theoretically, if we know the physical address of "swapper_pg_dir", instead of its virtual address, we can access all the memory pointed to by any kernel virtual address. How do you rationalize that we need to know "_text" and "_end"? Thanks, -Takahiro AKASHI > I already have makedumpfile patches [1] which uses _text and _end, but not > sending them to makedumpfile upstream, until you will be agreeing to take [2] in > future. Please let me know your opinion about it. If it would be acceptable then > I may send aarch64 makedumpfile improvements to upstream. > > [1] https://github.com/pratyushanand/makedumpfile/commit/d9590fec049976b8fee0d6b4e66e6f3e99ff1113 > [2] https://github.com/pratyushanand/linux/commit/1d94df20c575c725910c9c29a129b9f14e7e900b > > ~Pratyush > > > > > Signed-off-by: AKASHI Takahiro > > --- > > arch/arm64/kernel/machine_kexec.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > > index f270967..57a30fb 100644 > > --- a/arch/arm64/kernel/machine_kexec.c > > +++ b/arch/arm64/kernel/machine_kexec.c > > @@ -18,6 +18,7 @@ > > > > #include > > #include > > +#include > > #include > > > > #include "cpu-reset.h" > > @@ -278,3 +279,13 @@ void machine_crash_shutdown(struct pt_regs *regs) > > > > pr_info("Starting crashdump kernel...\n"); > > } > > + > > +void arch_crash_save_vmcoreinfo(void) > > +{ > > + VMCOREINFO_NUMBER(VA_BITS); > > + /* Please note VMCOREINFO_NUMBER() uses "%d", not "%x" */ > > + vmcoreinfo_append_str("NUMBER(kimage_voffset)=0x%llx\n", > > + kimage_voffset); > > + vmcoreinfo_append_str("NUMBER(PHYS_OFFSET)=0x%llx\n", > > + PHYS_OFFSET); > > +} > > -- > > 2.5.0 > > > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel at lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pa0-x236.google.com ([2607:f8b0:400e:c03::236]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bFb7y-0005xm-VR for kexec@lists.infradead.org; Wed, 22 Jun 2016 05:55:08 +0000 Received: by mail-pa0-x236.google.com with SMTP id wo6so13548959pac.3 for ; Tue, 21 Jun 2016 22:54:46 -0700 (PDT) Date: Wed, 22 Jun 2016 14:59:41 +0900 From: AKASHI Takahiro Subject: Re: [PATCH v19 10/13] arm64: kdump: add VMCOREINFO's for user-space coredump tools Message-ID: <20160622055940.GY20774@linaro.org> References: <6e96110e85e7b1167043d789e85f9c916fdf281a.1466120418.git.geoff@infradead.org> <20160620053222.GB14309@dhcppc9> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160620053222.GB14309@dhcppc9> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Pratyush Anand Cc: Mark Rutland , Geoff Levand , Catalin Marinas , Atsushi Kumagai , Will Deacon , marc.zyngier@arm.com, James Morse , kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org On Mon, Jun 20, 2016 at 11:02:22AM +0530, Pratyush Anand wrote: > +Atsushi > > Hi Takahiro, > > On 16/06/2016:11:48:28 PM, Geoff Levand wrote: > > From: AKASHI Takahiro > > > > For the current crash utility, we need to know, at least, > > - kimage_voffset > > - PHYS_OFFSET > > to handle the contents of core dump file (/proc/vmcore) correctly due to > > the introduction of KASLR (CONFIG_RANDOMIZE_BASE) in v4.6. > > This patch puts them as VMCOREINFO's into the file. > > > > - VA_BITS > > is also added for makedumpfile command. > > Thanks for adding them. They are quite helpful for makedumpfile as well. > > > More VMCOREINFO's may be added later. > > Yes, we will need to pass VMCOREINFO_SYMBOL(_text) and VMCOREINFO_SYMBOL(_end) > in order to work with makedumpfile. I know that adding those symbols is the easiest way, but theoretically, if we know the physical address of "swapper_pg_dir", instead of its virtual address, we can access all the memory pointed to by any kernel virtual address. How do you rationalize that we need to know "_text" and "_end"? Thanks, -Takahiro AKASHI > I already have makedumpfile patches [1] which uses _text and _end, but not > sending them to makedumpfile upstream, until you will be agreeing to take [2] in > future. Please let me know your opinion about it. If it would be acceptable then > I may send aarch64 makedumpfile improvements to upstream. > > [1] https://github.com/pratyushanand/makedumpfile/commit/d9590fec049976b8fee0d6b4e66e6f3e99ff1113 > [2] https://github.com/pratyushanand/linux/commit/1d94df20c575c725910c9c29a129b9f14e7e900b > > ~Pratyush > > > > > Signed-off-by: AKASHI Takahiro > > --- > > arch/arm64/kernel/machine_kexec.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > > index f270967..57a30fb 100644 > > --- a/arch/arm64/kernel/machine_kexec.c > > +++ b/arch/arm64/kernel/machine_kexec.c > > @@ -18,6 +18,7 @@ > > > > #include > > #include > > +#include > > #include > > > > #include "cpu-reset.h" > > @@ -278,3 +279,13 @@ void machine_crash_shutdown(struct pt_regs *regs) > > > > pr_info("Starting crashdump kernel...\n"); > > } > > + > > +void arch_crash_save_vmcoreinfo(void) > > +{ > > + VMCOREINFO_NUMBER(VA_BITS); > > + /* Please note VMCOREINFO_NUMBER() uses "%d", not "%x" */ > > + vmcoreinfo_append_str("NUMBER(kimage_voffset)=0x%llx\n", > > + kimage_voffset); > > + vmcoreinfo_append_str("NUMBER(PHYS_OFFSET)=0x%llx\n", > > + PHYS_OFFSET); > > +} > > -- > > 2.5.0 > > > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec