From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wm0-x235.google.com ([2a00:1450:400c:c09::235]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aMlEx-0001Td-DI for kexec@lists.infradead.org; Fri, 22 Jan 2016 23:35:40 +0000 Received: by mail-wm0-x235.google.com with SMTP id r129so2983186wmr.0 for ; Fri, 22 Jan 2016 15:35:18 -0800 (PST) Date: Sat, 23 Jan 2016 00:35:14 +0100 From: Ivan Delalande Subject: [PATCH] makedumpfile: readpage_elf: handle 0-pages not stored in the ELF file Message-ID: <20160122233514.GA25777@ycc.fr> MIME-Version: 1.0 Content-Disposition: inline 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: Masaki Tachibana , Minoru Usui , Daisuke Nishimura , Atsushi Kumagai Cc: kexec-ml Handle pages filled with zeros that are not stored in the ELF file directly, but have addresses between p_filesz and p_memsz of a segment. This allows makedumpfile to dump-dmesg from a previously makedumpfile-ed vmcore where all 0-pages were excluded (dump_level & 1) for example. Signed-off-by: Ivan Delalande --- elf_info.c | 22 ++++++++++++++++++++++ elf_info.h | 1 + makedumpfile.c | 16 ++++++++++++++++ 3 files changed, 39 insertions(+) diff --git a/elf_info.c b/elf_info.c index 8bce942..340e885 100644 --- a/elf_info.c +++ b/elf_info.c @@ -42,6 +42,7 @@ struct pt_load_segment { unsigned long long phys_end; unsigned long long virt_start; unsigned long long virt_end; + size_t mem_size; }; static int nr_cpus; /* number of cpu */ @@ -166,6 +167,7 @@ dump_Elf_load(Elf64_Phdr *prog, int num_load) pls->virt_start = prog->p_vaddr; pls->virt_end = pls->virt_start + prog->p_filesz; pls->file_offset = prog->p_offset; + pls->mem_size = prog->p_memsz; DEBUG_MSG("LOAD (%d)\n", num_load); DEBUG_MSG(" phys_start : %llx\n", pls->phys_start); @@ -584,6 +586,26 @@ offset_to_pt_load_end(off_t offset) } /* + * Return true if a page is in the zone between p_filesz and p_memsz of a + * segment, which is a page filled with zero and not stored in the ELF file. + */ +int +paddr_is_null(unsigned long long paddr) +{ + int i; + struct pt_load_segment *pls; + + for (i = 0; i < num_pt_loads; i++) { + pls = &pt_loads[i]; + if ((paddr >= pls->phys_start) + && (paddr + info->page_size + <= pls->phys_start + pls->mem_size)) + return TRUE; + } + return FALSE; +} + +/* * Judge whether the page is fractional or not. */ int diff --git a/elf_info.h b/elf_info.h index e712253..4823311 100644 --- a/elf_info.h +++ b/elf_info.h @@ -36,6 +36,7 @@ unsigned long long page_head_to_phys_start(unsigned long long head_paddr); unsigned long long page_head_to_phys_end(unsigned long long head_paddr); off_t offset_to_pt_load_start(off_t offset); off_t offset_to_pt_load_end(off_t offset); +int paddr_is_null(unsigned long long paddr); unsigned long long vaddr_to_paddr_general(unsigned long long vaddr); off_t vaddr_to_offset_slow(int fd, char *filename, unsigned long long vaddr); unsigned long long get_max_paddr(void); diff --git a/makedumpfile.c b/makedumpfile.c index fa0b779..120bfdc 100644 --- a/makedumpfile.c +++ b/makedumpfile.c @@ -654,6 +654,14 @@ readpage_elf(unsigned long long paddr, void *bufptr) phys_end = paddr + info->page_size; /* + * Check the 0-filled pages that are not in the ELF file. + */ + if (!offset1 && !offset2 && paddr_is_null(paddr)) { + memset(bufptr, 0, info->page_size); + return TRUE; + } + + /* * Check the case phys_start isn't aligned by page size like below: * * phys_start @@ -728,6 +736,14 @@ readpage_elf_parallel(int fd_memory, unsigned long long paddr, void *bufptr) phys_end = paddr + info->page_size; /* + * Check the 0-filled pages that are not in the ELF file. + */ + if (!offset1 && !offset2 && paddr_is_null(paddr)) { + memset(bufptr, 0, info->page_size); + return TRUE; + } + + /* * Check the case phys_start isn't aligned by page size like below: * * phys_start -- 2.7.0 -- Ivan "Colona" Delalande Arista Networks _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec