svn commit: r362121 - in head/sys: amd64/amd64 i386/i386

[Eric van Gyzen]

Author: vangyzen
Date: Fri Jun 12 21:17:56 2020
New Revision: 362121
URL: https://svnweb.freebsd.org/changeset/base/362121

Log:
  FPU init: allocate initial state from UMA to ensure alignment
  
  The Intel Instruction Set Reference says this about the XSAVE instruction:
  
      Use of a destination operand not aligned to 64-byte boundary
      (in either 64-bit or 32-bit modes) results in a general-protection
      (#GP) exception.
  
  This alignment happens naturally when all malloc buckets are powers
  of two.  However, this change is necessary on some systems when
  certain non-power-of-two (and non-multiple of 64) malloc buckets
  are defined.
  
  Reviewed by:	cem; kib; earlier version by jhb
  MFC after:	2 weeks
  Sponsored by:	Dell EMC Isilon
  Differential Revision:	https://reviews.freebsd.org/D25098

Modified:
  head/sys/amd64/amd64/fpu.c
  head/sys/i386/i386/npx.c

Modified: head/sys/amd64/amd64/fpu.c
==============================================================================
--- head/sys/amd64/amd64/fpu.c	Fri Jun 12 21:12:26 2020	(r362120)
+++ head/sys/amd64/amd64/fpu.c	Fri Jun 12 21:17:56 2020	(r362121)
@@ -372,8 +372,7 @@ fpuinitstate(void *arg __unused)
 	fpu_save_area_zone = uma_zcreate("FPU_save_area",
 	    cpu_max_ext_state_size, NULL, NULL, NULL, NULL,
 	    XSAVE_AREA_ALIGN - 1, 0);
-	fpu_initialstate = malloc(cpu_max_ext_state_size, M_DEVBUF,
-	    M_WAITOK | M_ZERO);
+	fpu_initialstate = uma_zalloc(fpu_save_area_zone, M_WAITOK | M_ZERO);
 	if (use_xsave) {
 		max_ext_n = flsl(xsave_mask);
 		xsave_area_desc = malloc(max_ext_n * sizeof(struct

Modified: head/sys/i386/i386/npx.c
==============================================================================
--- head/sys/i386/i386/npx.c	Fri Jun 12 21:12:26 2020	(r362120)
+++ head/sys/i386/i386/npx.c	Fri Jun 12 21:17:56 2020	(r362121)
@@ -483,8 +483,7 @@ npxinitstate(void *arg __unused)
 	fpu_save_area_zone = uma_zcreate("FPU_save_area",
 	    cpu_max_ext_state_size, NULL, NULL, NULL, NULL,
 	    XSAVE_AREA_ALIGN - 1, 0);
-	npx_initialstate = malloc(cpu_max_ext_state_size, M_DEVBUF,
-	    M_WAITOK | M_ZERO);
+	npx_initialstate = uma_zalloc(fpu_save_area_zone, M_WAITOK | M_ZERO);
 	if (use_xsave) {
 		if (xsave_mask >> 32 != 0)
 			max_ext_n = fls(xsave_mask >> 32) + 32;