0d647dbd38
failure of reading __per_cpu_load memory (bsc#1168798). OBS-URL: https://build.opensuse.org/package/show/Kernel:kdump/makedumpfile?expand=0&rev=147
55 lines
1.8 KiB
Diff
55 lines
1.8 KiB
Diff
From: "saito.kazuya@fujitsu.com" <saito.kazuya@fujitsu.com>
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Date: Thu, 21 May 2020 07:15:19 +0000
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Subject: sadump: Fix failure of reading __per_cpu_load memory
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References: bsc#1168798
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Upstream: merged
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Git-commit: c9e078531efaffbe6f780221d40bdac21a84855b
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Creating vmcore from sadump by makedumpfile fails with the following
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error messages since kernel-4.19 with PTI (Page Table Isolation)
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enabled:
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__vtop4_x86_64: Can't get a valid pte.
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readmem: Can't convert a virtual address(ffffffffb2986000) to physical address.
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readmem: type_addr: 0, addr:ffffffffb2986000, size:8
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per_cpu_init: Can't read __per_cpu_load memory.
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This is caused by the following patch:
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https://github.com/torvalds/linux/commit/c40a56a7818cfe735fc93a69e1875f8bba834483
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The above patch clears _PAGE_PRESENT bit of __per_cpu_load memory, so
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__vtop4_x86_64 fails to convert the virtual address of the
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__per_cpu_load.
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To fix this issue, this patch changes sanity check of per_cpu_ptr()
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to use address of the __per_cpu_load instead of data of the memory.
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Signed-off-by: Kazuya Saito <saito.kazuya@fujitsu.com>
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Signed-off-by: Kiyotaka Nakamura <kiyo@fujitsu.com>
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---
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sadump_info.c | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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diff --git a/sadump_info.c b/sadump_info.c
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index 46867ce..72a077b 100644
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--- a/sadump_info.c
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+++ b/sadump_info.c
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@@ -1732,11 +1732,11 @@ per_cpu_init(void)
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return FALSE;
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}
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- if (!readmem(VADDR, SYMBOL(__per_cpu_load), &si->__per_cpu_load,
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- sizeof(unsigned long))) {
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- ERRMSG("Can't read __per_cpu_load memory.\n");
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+ if (SYMBOL(__per_cpu_load) == NOT_FOUND_SYMBOL) {
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+ ERRMSG("Can't find __per_cpu_load symbol.\n");
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return FALSE;
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}
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+ si->__per_cpu_load = SYMBOL(__per_cpu_load);
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DEBUG_MSG("sadump: __per_cpu_load: %#lx\n", si->__per_cpu_load);
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DEBUG_MSG("sadump: __per_cpu_offset: LENGTH: %ld\n",
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--
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2.26.2
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