Thanks for your patch improvement. +#define VSYSCALL_START 0xffffffffff600000 +#define VSYSCALL_END 0xffffffffffe00000 FIXADDR_START, FIXADDR_TOP look good for me. But these are depended on kernel ver. So VSYSCALL_START/END are reasonable. 2.6.9-89.ELsmp (RHEL 4.8) 2.6.18-398.el5 (RHEL 5.11) FIXADDR_START = ffffffffff57c000 FIXADDR_TOP = ffffffffffdff000 2.6.32-71.el6.x86_64 (RHEL 6.0) 2.6.32-504.el6.x86_64 (RHEL 6.6) FIXADDR_START = ffffffffff577000 FIXADDR_TOP = ffffffffffdff000 3.10.0-229.el7.x86_64 (RHEL 7.1) 3.10.0-329.el7.x86_64 (RHEL 7.2) FIXADDR_START = ffffffffff525000 FIXADDR_TOP = ffffffffffdff000 4.2.3-300.fc23.x86_64 (Fedora 23) FIXADDR_START = ffffffffff567000 FIXADDR_TOP = ffffffffff7ff000 On 2016/01/05 1:44, Dave Anderson wrote: > > > ----- Original Message ----- >>> But because it is such a fundamental change that you are proposing, it might >>> make sense to create a check/macro that is specific to the vsyscall region. >> >> What is check/macro? How do we check what? >> Certainly, these addresses are vsyscall region. >> After applying this patch, crash looks read vsyscall region correctly. > > The vsyscall-region check fits more naturally in the x86_64_IS_VMALLOC_ADDR() function, > along with all of the other checks for non-unity-mapped addresses. > > Queued for crash-7.1.5: > > https://github.com/crash-utility/crash/commit/2e29d684a4583a45ae3c9b16014ab204eb6812fa > > Thanks for the report, > Dave > > >> >> >> >> crash> sym vsyscall >> // abbreviation // >> ffffffffff600000 (t) .vsyscall_0 >> ffffffffff600140 (t) .vsyscall_fn >> ffffffffff600180 (d) .vsyscall_gtod_data >> ffffffffff600180 (D) __vsyscall_gtod_data >> ffffffffff600400 (t) .vsyscall_1 >> ffffffffff600800 (t) .vsyscall_2 >> ffffffffff700680 (A) VDSO64_vsyscall_gtod_data >> >> crash> sym VDSO >> symbol not found: VDSO >> possible alternatives: >> ffffffffff700000 (A) VDSO64_PRELINK >> ffffffffff700670 (A) VDSO64_jiffies >> ffffffffff700678 (A) VDSO64_vgetcpu_mode >> ffffffffff700680 (A) VDSO64_vsyscall_gtod_data >> >> >> //////// not patched ///////// >> crash> dis .vsyscall_0 >> 0xffffffffff600000 <.vsyscall_0>: add %al,(%rax) >> 0xffffffffff600002 <vgettimeofday+2>: add %al,(%rax) >> 0xffffffffff600004 <vgettimeofday+4>: add %al,(%rax) >> 0xffffffffff600006 <vgettimeofday+6>: add %al,(%rax) >> 0xffffffffff600008 <vgettimeofday+8>: add %al,(%rax) >> 0xffffffffff60000a <vgettimeofday+10>: add %al,(%rax) >> // abbreviation // >> >> >> //////// after applying this patch ///////// >> crash> dis .vsyscall_0 >> 0xffffffffff600000 <.vsyscall_0>: push %rbp >> 0xffffffffff600001 <vgettimeofday+1>: mov %rsp,%rbp >> 0xffffffffff600004 <vgettimeofday+4>: push %r13 >> 0xffffffffff600006 <vgettimeofday+6>: push %r12 >> 0xffffffffff600008 <vgettimeofday+8>: mov %rdi,%r12 >> 0xffffffffff60000b <vgettimeofday+11>: push %rbx >> 0xffffffffff60000c <vgettimeofday+12>: mov %rsi,%rbx >> 0xffffffffff60000f <vgettimeofday+15>: sub $0x8,%rsp >> 0xffffffffff600013 <vgettimeofday+19>: test %rdi,%rdi >> 0xffffffffff600016 <vgettimeofday+22>: je 0xffffffffff6000d5 >> <vgettimeofday+213> >> // abbreviation // >> >> >> On 2015/12/22 22:42, Dave Anderson wrote: >>> >>> >>> ----- Original Message ----- >>>> I didn't check XEN HYPER MODE, I don't have XEN. >>>> If we need similar statement "if (kvaddr < MODULES_END)" >>>> please add inside in "if (XEN_HYPER_MODE())" (1859@x86_64_kvtop) >>>> >>>> >>>> >>>> >>>> >From ed300b74998e0923313e4fd14b9a41e305942b44 Mon Sep 17 00:00:00 2001 >>>> From: Nakajima Akira <nakajima.akira@xxxxxxxxxxxx> >>>> Date: Tue, 22 Dec 2015 15:46:42 +0900 >>>> Subject: [PATCH] Fix that particular kvaddr is converted to wrong paddr >>>> >>>> BUG INFO >>>> Particular kvaddr is converted to wrong paddr. >>>> You can see this bug on RHEL6_x86_64. (at present only RHEL6) >>>> (I checked RHEL5, RHEL7, Fedora21, Fedora23) >>> >>> >>> I am out of the office until January 4th (only checking email until then), >>> and will not >>> be able to look into this until then. But because it is such a fundamental >>> change that >>> you are proposing, it might make sense to create a check/macro that is >>> specific to >>> the vsyscall region. >>> >>> Thanks, >>> Dave >>> >>>> >>>> from /proc/kallsyms >>>> ffffffffff6008c0 D __jiffies >>>> >>>> /////////// wrong /////////// >>>> crash> vtop ffffffffff6008c0 >>>> VIRTUAL PHYSICAL >>>> ffffffffff6008c0 7f6008c0 >>>> >>>> PAGE PHYSICAL MAPPING INDEX CNT FLAGS >>>> ffffea00000623b8 1c11000 0 0 1 20000000000400 >>>> reserved >>>> >>>> >>>> crash> rd ffffffffff6008c0 >>>> ffffffffff6008c0: 0000000000000000 ........ >>>> >>>> >>>> /////////// correct /////////// >>>> crash> vtop ffffffffff6008c0 >>>> VIRTUAL PHYSICAL >>>> ffffffffff6008c0 1c118c0 >>>> >>>> PAGE PHYSICAL MAPPING INDEX CNT FLAGS >>>> ffffea00000623b8 1c11000 0 0 1 20000000000400 >>>> reserved >>>> >>>> >>>> crash> rd ffffffffff6008c0 >>>> ffffffffff6008c0: 00000000ffffe43a :....... >>>> >>>> Reported-by: Nakajima Akira <nakajima.akira@xxxxxxxxxxxx> >>>> Signed-off-by: Nakajima Akira <nakajima.akira@xxxxxxxxxxxx> >>>> >>>> --- >>>> x86_64.c | 28 +++++++++++++++------------- >>>> 1 files changed, 15 insertions(+), 13 deletions(-) >>>> >>>> diff --git a/x86_64.c b/x86_64.c >>>> index ff6fdd5..dab4d43 100644 >>>> --- a/x86_64.c >>>> +++ b/x86_64.c >>>> @@ -1872,19 +1872,21 @@ x86_64_kvtop(struct task_context *tc, ulong >>>> kvaddr, >>>> physaddr_t *paddr, int verbo >>>> fprintf(fp, "PAGE DIRECTORY: %lx\n", *pml4); >>>> } >>>> } else { >>>> - if (!vt->vmalloc_start) { >>>> - *paddr = x86_64_VTOP(kvaddr); >>>> - return TRUE; >>>> - } >>>> - >>>> - if (!IS_VMALLOC_ADDR(kvaddr)) { >>>> - *paddr = x86_64_VTOP(kvaddr); >>>> - if (!verbose) >>>> - return TRUE; >>>> - } >>>> - >>>> - if (XEN() && (kt->xen_flags & WRITABLE_PAGE_TABLES)) >>>> - return (x86_64_kvtop_xen_wpt(tc, kvaddr, paddr, verbose)); >>>> + if (kvaddr < MODULES_END) { >>>> + if (!vt->vmalloc_start) { >>>> + *paddr = x86_64_VTOP(kvaddr); >>>> + return TRUE; >>>> + } >>>> + >>>> + if (!IS_VMALLOC_ADDR(kvaddr)) { >>>> + *paddr = x86_64_VTOP(kvaddr); >>>> + if (!verbose) >>>> + return TRUE; >>>> + } >>>> + >>>> + if (XEN() && (kt->xen_flags & WRITABLE_PAGE_TABLES)) >>>> + return (x86_64_kvtop_xen_wpt(tc, kvaddr, paddr, verbose)); >>>> + } >>>> >>>> /* >>>> * pgd = pgd_offset_k(addr); >>>> -- >>>> 1.7.1 >>>> >>>> >>>> -- >>>> Crash-utility mailing list >>>> Crash-utility@xxxxxxxxxx >>>> https://www.redhat.com/mailman/listinfo/crash-utility >>> >>> -- >>> Crash-utility mailing list >>> Crash-utility@xxxxxxxxxx >>> https://www.redhat.com/mailman/listinfo/crash-utility >>> . >>> >> >> -- >> Crash-utility mailing list >> Crash-utility@xxxxxxxxxx >> https://www.redhat.com/mailman/listinfo/crash-utility >> > > -- > Crash-utility mailing list > Crash-utility@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/crash-utility > . > -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
