[newlib-cygwin] fhandler_proc.cc(format_proc_cpuinfo): add SERIALIZE instruction flag

[newlib-cygwin] fhandler_proc.cc(format_proc_cpuinfo): add SERIALIZE instruction flag

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=4ecc804d54ad1f6e9c64f7379cb24b319a9f3f2b

commit 4ecc804d54ad1f6e9c64f7379cb24b319a9f3f2b
Author: Brian Inglis <Brian.Inglis@SystematicSW.ab.ca>
Date:   Mon Aug 3 10:22:46 2020 -0600

    fhandler_proc.cc(format_proc_cpuinfo): add SERIALIZE instruction flag
    
    CPUID 7:0 EDX[14] serialize added in linux-next 5.8 by Ricardo Neri-Calderon:
    The Intel architecture defines a set of Serializing Instructions (a
    detailed definition can be found in Vol.3 Section 8.3 of the Intel "main"
    manual, SDM). However, these instructions do more than what is required,
    have side effects and/or may be rather invasive. Furthermore, some of
    these instructions are only available in kernel mode or may cause VMExits.
    Thus, software using these instructions only to serialize execution (as
    defined in the manual) must handle the undesired side effects.
    
    As indicated in the name, SERIALIZE is a new Intel architecture
    Serializing Instruction. Crucially, it does not have any of the mentioned
    side effects. Also, it does not cause VMExit and can be used in user mode.
    
    This new instruction is currently documented in the latest "extensions"
    manual (ISE). It will appear in the "main" manual in the future.
    
    https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/arch/x86/include/asm/cpufeatures.h?id=85b23fbc7d88f8c6e3951721802d7845bc39663d

Diff:
---
 winsup/cygwin/fhandler_proc.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/winsup/cygwin/fhandler_proc.cc b/winsup/cygwin/fhandler_proc.cc
index 4bb8bea17..72ffa89cd 100644
--- a/winsup/cygwin/fhandler_proc.cc
+++ b/winsup/cygwin/fhandler_proc.cc
@@ -1578,6 +1578,7 @@ format_proc_cpuinfo (void *, char *&destbuf)
           ftcprint (features1,  4, "fsrm");		   /* fast short REP MOVSB */
           ftcprint (features1,  8, "avx512_vp2intersect"); /* vec intcpt d/q */
           ftcprint (features1, 10, "md_clear");            /* verw clear buf */
+          ftcprint (features1, 14, "serialize");           /* SERIALIZE instruction */
           ftcprint (features1, 18, "pconfig");		   /* platform config */
           ftcprint (features1, 19, "arch_lbr");		   /* last branch records */
           ftcprint (features1, 28, "flush_l1d");	   /* flush l1d cache */