diff options
author | ToshikazuOhiwa <toshikazu_ohiwa@mail.toyota.co.jp> | 2020-03-30 09:24:26 +0900 |
---|---|---|
committer | ToshikazuOhiwa <toshikazu_ohiwa@mail.toyota.co.jp> | 2020-03-30 09:24:26 +0900 |
commit | 5b80bfd7bffd4c20d80b7c70a7130529e9a755dd (patch) | |
tree | b4bb18dcd1487dbf1ea8127e5671b7bb2eded033 /external/meta-virtualization/recipes-extended/xen/files/xen-disable-sse-before-inlines.patch | |
parent | 706ad73eb02caf8532deaf5d38995bd258725cb8 (diff) |
agl-basesystem
Diffstat (limited to 'external/meta-virtualization/recipes-extended/xen/files/xen-disable-sse-before-inlines.patch')
-rw-r--r-- | external/meta-virtualization/recipes-extended/xen/files/xen-disable-sse-before-inlines.patch | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/external/meta-virtualization/recipes-extended/xen/files/xen-disable-sse-before-inlines.patch b/external/meta-virtualization/recipes-extended/xen/files/xen-disable-sse-before-inlines.patch new file mode 100644 index 00000000..54a28ee4 --- /dev/null +++ b/external/meta-virtualization/recipes-extended/xen/files/xen-disable-sse-before-inlines.patch @@ -0,0 +1,140 @@ +From 6d50ae155c0f736aa6239eabf1bc8c8e3704742d Mon Sep 17 00:00:00 2001 +From: Christopher Clark <christopher.w.clark@gmail.com> +Date: Fri, 21 Sep 2018 08:28:02 -0700 +Subject: [PATCH v2] fuzz, test x86_emulator: disable sse before including + always_inline fns +To: xen-devel@lists.xenproject.org, + jbeulich@suse.com +Cc: ian.jackson@eu.citrix.com, + wei.liu2@citrix.com, + andrew.cooper3@citrix.com + +Workaround for compiler rejection of SSE-using always_inlines defined before +SSE is disabled. + +Compiling with _FORTIFY_SOURCE or higher levels of optimization enabled +will always_inline several library fns (memset, memcpy, ...) +(with gcc 8.2.0 and glibc 2.28). + +In fuzz and x86_emulator test, the compiler is instructed not +to generate SSE instructions via: #pragma GCC target("no-sse") +because those registers are needed for use by the workload. + +The combination above causes compilation failure as the inline functions +use those instructions. This is resolved by reordering the inclusion of +<stdio.h> and <string.h> to after the pragma disabling SSE generation. + +It would be preferable to locate the no-sse pragma within x86-emulate.h at the +top of the file, prior to including any other headers; unfortunately doing so +before <stdlib.h> causes compilation failure due to declaration of 'atof' with: + "SSE register return with SSE disabled". +Fortunately there is no (known) current dependency on any always_inline +SSE-inclined function declared in <stdlib.h> or any of its dependencies, so the +pragma is therefore issued immediately after inclusion of <stdlib.h> with a +comment introduced to explain its location there. + +Add compile-time checks for unwanted prior inclusion of <string.h> and +<stdio.h>, which are the two headers that provide the library functions that +are handled with wrappers and listed within "x86-emulate.h" as ones "we think +might access any of the FPU state". +* Use standard-defined "EOF" macro to detect prior <stdio.h> inclusion. +* Use "_STRING_H" (non-standardized guard macro) as best-effort + for detection of prior <string.h> inclusion. This is non-universally + viable but will provide error output on common GLIBC systems, so + provides some defensive coverage. + +Adds conditional #include <stdio.h> to x86-emulate.h because fwrite, printf, +etc. are referenced when WRAP has been defined. + +Signed-off-by: Christopher Clark <christopher.clark6@baesystems.com> +Reviewed-by: Jan Beulich <jbeulich@suse.com> +--- + tools/fuzz/x86_instruction_emulator/fuzz-emul.c | 10 +++++++-- + tools/tests/x86_emulator/wrappers.c | 1 - + tools/tests/x86_emulator/x86-emulate.h | 28 +++++++++++++++++++++++-- + 3 files changed, 34 insertions(+), 5 deletions(-) + +diff --git a/tools/fuzz/x86_instruction_emulator/fuzz-emul.c b/tools/fuzz/x86_instruction_emulator/fuzz-emul.c +index 03a2473..0ffd0fb 100644 +--- a/tools/fuzz/x86_instruction_emulator/fuzz-emul.c ++++ b/tools/fuzz/x86_instruction_emulator/fuzz-emul.c +@@ -6,9 +6,7 @@ + #include <stdbool.h> + #include <stddef.h> + #include <stdint.h> +-#include <stdio.h> + #include <stdlib.h> +-#include <string.h> + #include <sys/types.h> + #include <sys/stat.h> + #include <sys/mman.h> +@@ -16,6 +14,14 @@ + #include <xen/xen.h> + + #include "x86-emulate.h" ++/* ++ * include "x86-emulate.h" prior to <stdio.h> and <string.h>: ++ * x86-emulate.h disables use of SSE registers, while <stdio.h> and <string.h> ++ * declare functions that may be always_inline and use those registers ++ * unless they have been disabled earlier, which can fail to compile. ++ */ ++#include <stdio.h> ++#include <string.h> + #include "fuzz-emul.h" + + #define MSR_INDEX_MAX 16 +diff --git a/tools/tests/x86_emulator/wrappers.c b/tools/tests/x86_emulator/wrappers.c +index d02013c..eba7cc9 100644 +--- a/tools/tests/x86_emulator/wrappers.c ++++ b/tools/tests/x86_emulator/wrappers.c +@@ -1,5 +1,4 @@ + #include <stdarg.h> +-#include <stdio.h> + + #define WRAP(x) typeof(x) emul_##x + #include "x86-emulate.h" +diff --git a/tools/tests/x86_emulator/x86-emulate.h b/tools/tests/x86_emulator/x86-emulate.h +index b249e46..07ea1e8 100644 +--- a/tools/tests/x86_emulator/x86-emulate.h ++++ b/tools/tests/x86_emulator/x86-emulate.h +@@ -3,11 +3,35 @@ + #include <stddef.h> + #include <stdint.h> + #include <stdlib.h> +-#include <string.h> +- ++/* ++ * Use of sse registers must be disabled prior to the definition of ++ * always_inline functions that would use them (memcpy, memset, etc), ++ * so do this as early as possible, aiming to be before any always_inline ++ * functions that are used are declared. ++ * Unfortunately, this cannot be done prior to inclusion of <stdlib.h> ++ * due to functions such as 'atof' that have SSE register return declared, ++ * so do so here, immediately after that. ++ */ + #if __GNUC__ >= 6 + #pragma GCC target("no-sse") + #endif ++ /* ++ * Attempt detection of unwanted prior inclusion of some headers known to use ++ * always_inline with SSE registers in some library / compiler / optimization ++ * combinations. ++ */ ++#ifdef _STRING_H ++#error "Must not include <string.h> before x86-emulate.h" ++#endif ++#include <string.h> ++ ++/* EOF is a standard macro defined in <stdio.h> so use it for detection */ ++#ifdef EOF ++#error "Must not include <stdio.h> before x86-emulate.h" ++#endif ++#ifdef WRAP ++#include <stdio.h> ++#endif + + #include <xen/xen.h> + +-- +2.1.4 + |