From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-f45.google.com ([74.125.83.45]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dhCjC-0005bJ-GB for kexec@lists.infradead.org; Mon, 14 Aug 2017 10:36:22 +0000 Received: by mail-pg0-f45.google.com with SMTP id u5so44781453pgn.0 for ; Mon, 14 Aug 2017 03:35:48 -0700 (PDT) Subject: Re: [PATCH] makedumpfile: arm64: Fix page table walk of 1GB section References: <20170805224107.4966-1-bradleybolen@gmail.com> <20170805224107.4966-2-bradleybolen@gmail.com> <0910DD04CBD6DE4193FCF86B9C00BE9701EF8C02@BPXM01GP.gisp.nec.co.jp> From: Pratyush Anand Message-ID: Date: Mon, 14 Aug 2017 16:05:44 +0530 MIME-Version: 1.0 In-Reply-To: <0910DD04CBD6DE4193FCF86B9C00BE9701EF8C02@BPXM01GP.gisp.nec.co.jp> Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed"; DelSp="yes" Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Atsushi Kumagai , Bradley Bolen Cc: "kexec@lists.infradead.org" On Monday 14 August 2017 02:07 PM, Atsushi Kumagai wrote: > Hello Bradley, > > Sorry for my late reply, I'll merge this patch into v1.6.3. Sorry, I missed it as well. Patch looks fine to me.However, I think /* 1GB Section*/ comment can be improved. Infact, other existing /* 1GB Section*/ comment for PMD type is wrong. > Thanks for your work. > > Regards, > Atsushi Kumagai > >> makedumpfile was generating large (> 500MB) vmcore files for an arm64 >> board with 2GB of DRAM. It was not excluding any pages because the >> mem_map address was not being converted correctly. >> >> readmem: Can't convert a virtual address(ffffffc07fff6000) to physical >> address. >> readmem: type_addr: 0, addr:ffffffc07fff6000, size:16 >> section_mem_map_addr: Can't get a struct mem_section(ffffffc07fff6000). >> mem_map (0) >> mem_map : 0 >> >> makedumpfile was not handling 1GB sections in the PGD and was trying to >> drill down to a PTE in which it was trying to dereference invalid >> memory. This patch adds code to check the PGD for a section type and >> handle it instead of treating it as a table entry. >> >> Signed-off-by: Bradley Bolen >> --- >> arch/arm64.c | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/arch/arm64.c b/arch/arm64.c >> index 958f57f..cae4b70 100644 >> --- a/arch/arm64.c >> +++ b/arch/arm64.c >> @@ -57,6 +57,8 @@ static unsigned long kimage_voffset; >> #define PGDIR_SHIFT ((PAGESHIFT() - 3) * pgtable_level + 3) >> #define PTRS_PER_PGD (1 << (va_bits - PGDIR_SHIFT)) >> #define PUD_SHIFT get_pud_shift_arm64() >> +#define PUD_SIZE (1UL << PUD_SHIFT) >> +#define PUD_MASK (~(PUD_SIZE - 1)) >> #define PTRS_PER_PTE (1 << (PAGESHIFT() - 3)) >> #define PTRS_PER_PUD PTRS_PER_PTE >> #define PMD_SHIFT ((PAGESHIFT() - 3) * 2 + 3) >> @@ -79,6 +81,10 @@ static unsigned long kimage_voffset; >> #define PMD_TYPE_SECT 1 >> #define PMD_TYPE_TABLE 3 >> >> +#define PUD_TYPE_MASK 3 >> +#define PUD_TYPE_SECT 1 >> +#define PUD_TYPE_TABLE 3 >> + >> #define pgd_index(vaddr) (((vaddr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) >> #define pgd_offset(pgdir, vaddr) ((pgd_t *)(pgdir) + pgd_index(vaddr)) >> >> @@ -253,6 +259,13 @@ vaddr_to_paddr_arm64(unsigned long vaddr) >> return NOT_PADDR; >> } >> >> + if ((pud_val(pudv) & PUD_TYPE_MASK) == PUD_TYPE_SECT) { >> + /* 1GB section */ May be we can write above comment like: /* 1GB section for Page Table level = 4 and Page Size = 4KB*/ I think the other existing /* 1GB section */ comment for PMD_TYPE should be /* 512MB section for Page Table level = 3 and Page Size = 64KB*/ >> + paddr = (pud_val(pudv) & (PUD_MASK & PMD_SECTION_MASK)) >> + + (vaddr & (PUD_SIZE - 1)); >> + return paddr; >> + } >> + >> pmda = pmd_offset(puda, &pudv, vaddr); >> if (!readmem(PADDR, (unsigned long long)pmda, &pmdv, sizeof(pmdv))) { >> ERRMSG("Can't read pmd\n"); >> -- >> 1.9.3 >> >> >> _______________________________________________ >> kexec mailing list >> kexec@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/kexec > > -- Regards Pratyush _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec