From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 02 Dec 2016 19:22:39 +0000 Subject: Re: [PATCH v2 2/5] ia64: reuse append_elf_note() and final_note() functions Message-Id: <87mvge16gw.fsf@xmission.com> List-Id: References: <148007477669.1053.4107773905913128028.stgit@hbathini.in.ibm.com> <148007484315.1053.12317233313990302812.stgit@hbathini.in.ibm.com> <20161201045653.GA13670@dhcp-128-65.nay.redhat.com> In-Reply-To: (Hari Bathini's message of "Fri, 2 Dec 2016 16:56:48 +0530") MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Hari Bathini Cc: Dave Young , linux-kernel@vger.kernel.org, fenghua.yu@intel.com, tony.luck@intel.com, linux-ia64@vger.kernel.org, kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, Michael Ellerman , vgoyal@redhat.com Hari Bathini writes: > Hi Dave, > > > Thanks for the review. > > > On Thursday 01 December 2016 10:26 AM, Dave Young wrote: >> Hi Hari >> >> Personally I like V1 more, but split the patch 2 is easier for ia64 >> people to reivew. I did basic x86 testing, it runs ok. >> >> On 11/25/16 at 05:24pm, Hari Bathini wrote: >>> Get rid of multiple definitions of append_elf_note() & final_note() >>> functions. Reuse these functions compiled under CONFIG_CRASH_CORE. >>> >>> Signed-off-by: Hari Bathini >>> --- >>> arch/ia64/kernel/crash.c | 22 ---------------------- >>> include/linux/crash_core.h | 4 ++++ >>> kernel/crash_core.c | 6 +++--- >>> kernel/kexec_core.c | 28 ---------------------------- >>> 4 files changed, 7 insertions(+), 53 deletions(-) >>> >>> diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c >>> index 2955f35..75859a0 100644 >>> --- a/arch/ia64/kernel/crash.c >>> +++ b/arch/ia64/kernel/crash.c >>> @@ -27,28 +27,6 @@ static int kdump_freeze_monarch; >>> static int kdump_on_init = 1; >>> static int kdump_on_fatal_mca = 1; >>> -static inline Elf64_Word >>> -*append_elf_note(Elf64_Word *buf, char *name, unsigned type, void *data, >>> - size_t data_len) >>> -{ >>> - struct elf_note *note = (struct elf_note *)buf; >>> - note->n_namesz = strlen(name) + 1; >>> - note->n_descsz = data_len; >>> - note->n_type = type; >>> - buf += (sizeof(*note) + 3)/4; >>> - memcpy(buf, name, note->n_namesz); >>> - buf += (note->n_namesz + 3)/4; >>> - memcpy(buf, data, data_len); >>> - buf += (data_len + 3)/4; >>> - return buf; >>> -} >>> - >>> -static void >>> -final_note(void *buf) >>> -{ >>> - memset(buf, 0, sizeof(struct elf_note)); >>> -} >>> - >> The above IA64 version looks better than the functions in kexec_core.c >> about the Elf64_Word type usage and the simpler final_note function. > > Hmmm.. Is void* better over Elf64_Word* to be agnostic of Elf32 or > Elf64 type? Both Elf64_Word and Elf32_Word result in a u32. So I expect the right solution is to add a definition of Elf_Word to include/linux/elf.h and to make the buffer "Elf_Word *buf". That way we preserve the alignment knowledge, while making the code depend on 32bit or 64bit. Eric