linux_dsm_epyc7002/arch/x86
Youquan Song 278b917f8c x86/mce: Add _ASM_EXTABLE_CPY for copy user access
_ASM_EXTABLE_UA is a general exception entry to record the exception fixup
for all exception spots between kernel and user space access.

To enable recovery from machine checks while coping data from user
addresses it is necessary to be able to distinguish the places that are
looping copying data from those that copy a single byte/word/etc.

Add a new macro _ASM_EXTABLE_CPY and use it in place of _ASM_EXTABLE_UA
in the copy functions.

Record the exception reason number to regs->ax at
ex_handler_uaccess which is used to check MCE triggered.

The new fixup routine ex_handler_copy() is almost an exact copy of
ex_handler_uaccess() The difference is that it sets regs->ax to the trap
number. Following patches use this to avoid trying to copy remaining
bytes from the tail of the copy and possibly hitting the poison again.

New mce.kflags bit MCE_IN_KERNEL_COPYIN will be used by mce_severity()
calculation to indicate that a machine check is recoverable because the
kernel was copying from user space.

Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201006210910.21062-4-tony.luck@intel.com
2020-10-07 11:19:11 +02:00
..
boot Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
configs x86/defconfigs: Refresh defconfig files 2020-07-25 12:02:14 +02:00
crypto crypto: x86/curve25519 - Remove unused carry variables 2020-07-31 18:25:29 +10:00
entry all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
events perf/x86/rapl: Add support for Intel SPR platform 2020-08-14 12:35:12 +02:00
hyperv vmalloc: fix the owner argument for the new __vmalloc_node_range callers 2020-07-03 16:15:25 -07:00
ia32 mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
include x86/mce: Add _ASM_EXTABLE_CPY for copy user access 2020-10-07 11:19:11 +02:00
kernel x86/mce: Provide method to find out the type of an exception handler 2020-10-07 11:08:59 +02:00
kvm PPC: 2020-08-12 12:25:06 -07:00
lib x86/mce: Add _ASM_EXTABLE_CPY for copy user access 2020-10-07 11:19:11 +02:00
math-emu Merge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 09:29:25 -07:00
mm x86/mce: Add _ASM_EXTABLE_CPY for copy user access 2020-10-07 11:19:11 +02:00
net bpf, i386: Remove unneeded conversion to bool 2020-05-07 16:29:14 +02:00
oprofile
pci pci-v5.9-changes 2020-08-07 18:48:15 -07:00
platform mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
power Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
purgatory Misc fixes and small updates all around the place: 2020-08-15 10:38:03 -07:00
ras treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
realmode Rebase locking/kcsan to locking/urgent 2020-06-11 20:02:46 +02:00
tools .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
um kbuild: remove cc-option test of -fno-stack-protector 2020-07-07 11:13:10 +09:00
video
xen xen: branch for v5.9-rc1b 2020-08-14 13:34:37 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Kbuild
Kconfig x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
Kconfig.assembler x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
Kconfig.cpu treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Kconfig.debug x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
Makefile Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
Makefile_32.cpu
Makefile.um