From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f47.google.com (mail-wm0-f47.google.com [74.125.82.47]) by kanga.kvack.org (Postfix) with ESMTP id 8EB2C6B0005 for ; Tue, 5 Jan 2016 08:32:45 -0500 (EST) Received: by mail-wm0-f47.google.com with SMTP id u188so23275567wmu.1 for ; Tue, 05 Jan 2016 05:32:45 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id dl6si152543341wjb.82.2016.01.05.05.32.44 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 05 Jan 2016 05:32:44 -0800 (PST) Subject: Re: [PATCH 22/32] x86, pkeys: dump PTE pkey in /proc/pid/smaps References: <20151214190542.39C4886D@viggo.jf.intel.com> <20151214190619.BA65327A@viggo.jf.intel.com> From: Vlastimil Babka Message-ID: <568BC5FA.2080800@suse.cz> Date: Tue, 5 Jan 2016 14:32:42 +0100 MIME-Version: 1.0 In-Reply-To: <20151214190619.BA65327A@viggo.jf.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, dave.hansen@linux.intel.com On 12/14/2015 08:06 PM, Dave Hansen wrote: > From: Dave Hansen $SUBJ is a bit confusing in that it's dumping stuff from VMA, not PTE's? It could be also useful to extend dump_vma() appropriately. Currently there are no string translations for the new "flags" (but one can figure it out from the raw value). But maybe we should print pkey separately in dump_vma() as you do here. I have a series in flight [1] that touches dump_vma() and the flags printing in general, so to avoid conflicts, handling pkeys there could wait. But mentioning it now for less chance of being forgotten... [1] https://lkml.org/lkml/2015/12/18/178 - a previous version is in mmotm and this should replace it after 4.5-rc1 > The protection key can now be just as important as read/write > permissions on a VMA. We need some debug mechanism to help > figure out if it is in play. smaps seems like a logical > place to expose it. > > arch/x86/kernel/setup.c is a bit of a weirdo place to put > this code, but it already had seq_file.h and there was not > a much better existing place to put it. > > We also use no #ifdef. If protection keys is .config'd out > we will get the same function as if we used the weak generic > function. > > Signed-off-by: Dave Hansen > Reviewed-by: Thomas Gleixner > --- > > b/arch/x86/kernel/setup.c | 9 +++++++++ > b/fs/proc/task_mmu.c | 14 ++++++++++++++ > 2 files changed, 23 insertions(+) > > diff -puN arch/x86/kernel/setup.c~pkeys-40-smaps arch/x86/kernel/setup.c > --- a/arch/x86/kernel/setup.c~pkeys-40-smaps 2015-12-14 10:42:48.777070739 -0800 > +++ b/arch/x86/kernel/setup.c 2015-12-14 10:42:48.782070963 -0800 > @@ -112,6 +112,7 @@ > #include > #include > #include > +#include > > /* > * max_low_pfn_mapped: highest direct mapped pfn under 4GB > @@ -1282,3 +1283,11 @@ static int __init register_kernel_offset > return 0; > } > __initcall(register_kernel_offset_dumper); > + > +void arch_show_smap(struct seq_file *m, struct vm_area_struct *vma) > +{ > + if (!boot_cpu_has(X86_FEATURE_OSPKE)) > + return; > + > + seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); > +} > diff -puN fs/proc/task_mmu.c~pkeys-40-smaps fs/proc/task_mmu.c > --- a/fs/proc/task_mmu.c~pkeys-40-smaps 2015-12-14 10:42:48.779070829 -0800 > +++ b/fs/proc/task_mmu.c 2015-12-14 10:42:48.783071008 -0800 > @@ -615,11 +615,20 @@ static void show_smap_vma_flags(struct s > [ilog2(VM_MERGEABLE)] = "mg", > [ilog2(VM_UFFD_MISSING)]= "um", > [ilog2(VM_UFFD_WP)] = "uw", > +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS > + /* These come out via ProtectionKey: */ > + [ilog2(VM_PKEY_BIT0)] = "", > + [ilog2(VM_PKEY_BIT1)] = "", > + [ilog2(VM_PKEY_BIT2)] = "", > + [ilog2(VM_PKEY_BIT3)] = "", > +#endif > }; > size_t i; > > seq_puts(m, "VmFlags: "); > for (i = 0; i < BITS_PER_LONG; i++) { > + if (!mnemonics[i][0]) > + continue; > if (vma->vm_flags & (1UL << i)) { > seq_printf(m, "%c%c ", > mnemonics[i][0], mnemonics[i][1]); > @@ -657,6 +666,10 @@ static int smaps_hugetlb_range(pte_t *pt > } > #endif /* HUGETLB_PAGE */ > > +void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma) > +{ > +} > + > static int show_smap(struct seq_file *m, void *v, int is_pid) > { > struct vm_area_struct *vma = v; > @@ -713,6 +726,7 @@ static int show_smap(struct seq_file *m, > (vma->vm_flags & VM_LOCKED) ? > (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); > > + arch_show_smap(m, vma); > show_smap_vma_flags(m, vma); > m_cache_vma(m, vma); > return 0; > _ > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org