From: Takao Indoh <indou.takao@jp.fujitsu.com>
To: ats-kumagai@wm.jp.nec.com, d.hatayama@jp.fujitsu.com
Subject: [makedumpfile PATCH] sadump: Fix a problem of PTI enabled kernel
Date: Fri, 26 Jan 2018 09:22:26 +0900
Cc: kexec@lists.infradead.org
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This patch fixes a problme that a dumpfile of sadump cannot be handled by
makedumpfile when Page Table Isolation(PTI) is enabled.
When PTI is enabled, bit 12 of CR3 register is used to split user space and
kernel space. Also bit 11:0 is used for Process Context IDentifiers(PCID). To
open a dump file of sadump, a value of CR3 is used to calculate KASLR offset and
phys_base, therefore this patch fixes to mask CR3 register value collectly for
PTI enabled kernel.
Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
---
makedumpfile.c | 2 ++
makedumpfile.h | 2 ++
sadump_info.c | 9 ++++++++-
3 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/makedumpfile-1.6.2/makedumpfile.c b/makedumpfile-1.6.2/makedumpfile.c
index 64b404a..247a056 100644
--- a/makedumpfile-1.6.2/makedumpfile.c
+++ b/makedumpfile-1.6.2/makedumpfile.c
@@ -1557,6 +1557,8 @@ get_symbol_info(void)
SYMBOL_INIT(divide_error, "divide_error");
SYMBOL_INIT(idt_table, "idt_table");
SYMBOL_INIT(saved_command_line, "saved_command_line");
+ SYMBOL_INIT(pti_init, "pti_init");
+ SYMBOL_INIT(kaiser_init, "kaiser_init");
return TRUE;
}
diff --git a/makedumpfile-1.6.2/makedumpfile.h b/makedumpfile-1.6.2/makedumpfile.h
index 57cf4d9..8ee4d29 100644
--- a/makedumpfile-1.6.2/makedumpfile.h
+++ b/makedumpfile-1.6.2/makedumpfile.h
@@ -1608,6 +1608,8 @@ struct symbol_table {
unsigned long long divide_error;
unsigned long long idt_table;
unsigned long long saved_command_line;
+ unsigned long long pti_init;
+ unsigned long long kaiser_init;
/*
* symbols on ppc64 arch
diff --git a/makedumpfile-1.6.2/sadump_info.c b/makedumpfile-1.6.2/sadump_info.c
index 148d4ba..dd50d48 100644
--- a/makedumpfile-1.6.2/sadump_info.c
+++ b/makedumpfile-1.6.2/sadump_info.c
@@ -1362,6 +1362,9 @@ finish:
* kernel. Retrieve vmcoreinfo from address of "elfcorehdr=" and
* get kaslr_offset and phys_base from vmcoreinfo.
*/
+#define PTI_USER_PGTABLE_BIT (info->page_shift)
+#define PTI_USER_PGTABLE_MASK (1 << PTI_USER_PGTABLE_BIT)
+#define CR3_PCID_MASK 0xFFFull
int
calc_kaslr_offset(void)
{
@@ -1389,7 +1392,11 @@ calc_kaslr_offset(void)
}
idtr = ((uint64_t)smram.IdtUpper)<<32 | (uint64_t)smram.IdtLower;
- cr3 = smram.Cr3;
+ if ((SYMBOL(pti_init) != NOT_FOUND_SYMBOL) ||
+ (SYMBOL(kaiser_init) != NOT_FOUND_SYMBOL))
+ cr3 = smram.Cr3 & ~(CR3_PCID_MASK|PTI_USER_PGTABLE_MASK);
+ else
+ cr3 = smram.Cr3 & ~CR3_PCID_MASK;
/* Convert virtual address of IDT table to physical address */
if ((idtr_paddr = vtop4_x86_64_pagetable(idtr, cr3)) == NOT_PADDR)
--
1.8.3.1
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