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authorDan Williams <dan.j.williams@intel.com>2018-05-01 06:49:45 -0700
committerDan Williams <dan.j.williams@intel.com>2018-05-22 23:18:31 -0700
commit5d8beee20d89e34ff1dcb0da84adf7607858c59d (patch)
tree8ec057691e285c7244b82bc47b077fa0ce50fae5 /arch/x86/lib
parent6dfdb2b6d877d654c8c7b59d7166f4d672fba4e8 (diff)
x86, nfit_test: Add unit test for memcpy_mcsafe()
Given the fact that the ACPI "EINJ" (error injection) facility is not universally available, implement software infrastructure to validate the memcpy_mcsafe() exception handling implementation. For each potential read exception point in memcpy_mcsafe(), inject a emulated exception point at the address identified by 'mcsafe_inject' variable. With this infrastructure implement a test to validate that the 'bytes remaining' calculation is correct for a range of various source buffer alignments. This code is compiled out by default. The CONFIG_MCSAFE_DEBUG configuration symbol needs to be manually enabled by editing Kconfig.debug. I.e. this functionality can not be accidentally enabled by a user / distro, it's only for development. Cc: <x86@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/memcpy_64.S10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index c3b527a9f95d..298ef1479240 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -3,6 +3,7 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
+#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@@ -183,6 +184,9 @@ ENTRY(memcpy_orig)
ENDPROC(memcpy_orig)
#ifndef CONFIG_UML
+
+MCSAFE_TEST_CTL
+
/*
* __memcpy_mcsafe - memory copy with machine check exception handling
* Note that we only catch machine checks when reading the source addresses.
@@ -206,6 +210,8 @@ ENTRY(__memcpy_mcsafe)
subl %ecx, %edx
.L_read_leading_bytes:
movb (%rsi), %al
+ MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
+ MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
.L_write_leading_bytes:
movb %al, (%rdi)
incq %rsi
@@ -221,6 +227,8 @@ ENTRY(__memcpy_mcsafe)
.L_read_words:
movq (%rsi), %r8
+ MCSAFE_TEST_SRC %rsi 8 .E_read_words
+ MCSAFE_TEST_DST %rdi 8 .E_write_words
.L_write_words:
movq %r8, (%rdi)
addq $8, %rsi
@@ -237,6 +245,8 @@ ENTRY(__memcpy_mcsafe)
movl %edx, %ecx
.L_read_trailing_bytes:
movb (%rsi), %al
+ MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
+ MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
.L_write_trailing_bytes:
movb %al, (%rdi)
incq %rsi