linux_dsm_epyc7002/arch/sparc/lib/U1memcpy.S

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/* U1memcpy.S: UltraSPARC-I/II/IIi/IIe optimized memcpy.
*
* Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com)
* Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
*/
#ifdef __KERNEL__
#include <asm/visasm.h>
#include <asm/asi.h>
#define GLOBAL_SPARE g7
#else
#define GLOBAL_SPARE g5
#define ASI_BLK_P 0xf0
#define FPRS_FEF 0x04
#ifdef MEMCPY_DEBUG
#define VISEntry rd %fprs, %o5; wr %g0, FPRS_FEF, %fprs; \
clr %g1; clr %g2; clr %g3; subcc %g0, %g0, %g0;
#define VISExit and %o5, FPRS_FEF, %o5; wr %o5, 0x0, %fprs
#else
#define VISEntry rd %fprs, %o5; wr %g0, FPRS_FEF, %fprs
#define VISExit and %o5, FPRS_FEF, %o5; wr %o5, 0x0, %fprs
#endif
#endif
#ifndef EX_LD
#define EX_LD(x) x
#endif
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
#ifndef EX_LD_FP
#define EX_LD_FP(x) x
#endif
#ifndef EX_ST
#define EX_ST(x) x
#endif
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
#ifndef EX_ST_FP
#define EX_ST_FP(x) x
#endif
#ifndef EX_RETVAL
#define EX_RETVAL(x) x
#endif
#ifndef LOAD
#define LOAD(type,addr,dest) type [addr], dest
#endif
#ifndef LOAD_BLK
#define LOAD_BLK(addr,dest) ldda [addr] ASI_BLK_P, dest
#endif
#ifndef STORE
#define STORE(type,src,addr) type src, [addr]
#endif
#ifndef STORE_BLK
#define STORE_BLK(src,addr) stda src, [addr] ASI_BLK_P
#endif
#ifndef FUNC_NAME
#define FUNC_NAME memcpy
#endif
#ifndef PREAMBLE
#define PREAMBLE
#endif
#ifndef XCC
#define XCC xcc
#endif
#define FREG_FROB(f1, f2, f3, f4, f5, f6, f7, f8, f9) \
faligndata %f1, %f2, %f48; \
faligndata %f2, %f3, %f50; \
faligndata %f3, %f4, %f52; \
faligndata %f4, %f5, %f54; \
faligndata %f5, %f6, %f56; \
faligndata %f6, %f7, %f58; \
faligndata %f7, %f8, %f60; \
faligndata %f8, %f9, %f62;
#define MAIN_LOOP_CHUNK(src, dest, fdest, fsrc, len, jmptgt) \
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD_BLK(%src, %fdest)); \
EX_ST_FP(STORE_BLK(%fsrc, %dest)); \
add %src, 0x40, %src; \
subcc %len, 0x40, %len; \
be,pn %xcc, jmptgt; \
add %dest, 0x40, %dest; \
#define LOOP_CHUNK1(src, dest, len, branch_dest) \
MAIN_LOOP_CHUNK(src, dest, f0, f48, len, branch_dest)
#define LOOP_CHUNK2(src, dest, len, branch_dest) \
MAIN_LOOP_CHUNK(src, dest, f16, f48, len, branch_dest)
#define LOOP_CHUNK3(src, dest, len, branch_dest) \
MAIN_LOOP_CHUNK(src, dest, f32, f48, len, branch_dest)
#define DO_SYNC membar #Sync;
#define STORE_SYNC(dest, fsrc) \
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE_BLK(%fsrc, %dest)); \
add %dest, 0x40, %dest; \
DO_SYNC
#define STORE_JUMP(dest, fsrc, target) \
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE_BLK(%fsrc, %dest)); \
add %dest, 0x40, %dest; \
ba,pt %xcc, target; \
nop;
#define FINISH_VISCHUNK(dest, f0, f1, left) \
subcc %left, 8, %left;\
bl,pn %xcc, 95f; \
faligndata %f0, %f1, %f48; \
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE(std, %f48, %dest)); \
add %dest, 8, %dest;
#define UNEVEN_VISCHUNK_LAST(dest, f0, f1, left) \
subcc %left, 8, %left; \
bl,pn %xcc, 95f; \
fsrc2 %f0, %f1;
#define UNEVEN_VISCHUNK(dest, f0, f1, left) \
UNEVEN_VISCHUNK_LAST(dest, f0, f1, left) \
ba,a,pt %xcc, 93f;
.register %g2,#scratch
.register %g3,#scratch
.text
.align 64
.globl FUNC_NAME
.type FUNC_NAME,#function
FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */
srlx %o2, 31, %g2
cmp %g2, 0
tne %xcc, 5
PREAMBLE
mov %o0, %o4
cmp %o2, 0
be,pn %XCC, 85f
or %o0, %o1, %o3
cmp %o2, 16
blu,a,pn %XCC, 80f
or %o3, %o2, %o3
cmp %o2, (5 * 64)
blu,pt %XCC, 70f
andcc %o3, 0x7, %g0
/* Clobbers o5/g1/g2/g3/g7/icc/xcc. */
VISEntry
/* Is 'dst' already aligned on an 64-byte boundary? */
andcc %o0, 0x3f, %g2
be,pt %XCC, 2f
/* Compute abs((dst & 0x3f) - 0x40) into %g2. This is the number
* of bytes to copy to make 'dst' 64-byte aligned. We pre-
* subtract this from 'len'.
*/
sub %o0, %o1, %GLOBAL_SPARE
sub %g2, 0x40, %g2
sub %g0, %g2, %g2
sub %o2, %g2, %o2
andcc %g2, 0x7, %g1
be,pt %icc, 2f
and %g2, 0x38, %g2
1: subcc %g1, 0x1, %g1
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD(ldub, %o1 + 0x00, %o3))
EX_ST_FP(STORE(stb, %o3, %o1 + %GLOBAL_SPARE))
bgu,pt %XCC, 1b
add %o1, 0x1, %o1
add %o1, %GLOBAL_SPARE, %o0
2: cmp %g2, 0x0
and %o1, 0x7, %g1
be,pt %icc, 3f
alignaddr %o1, %g0, %o1
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD(ldd, %o1, %f4))
1: EX_LD_FP(LOAD(ldd, %o1 + 0x8, %f6))
add %o1, 0x8, %o1
subcc %g2, 0x8, %g2
faligndata %f4, %f6, %f0
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE(std, %f0, %o0))
be,pn %icc, 3f
add %o0, 0x8, %o0
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD(ldd, %o1 + 0x8, %f4))
add %o1, 0x8, %o1
subcc %g2, 0x8, %g2
faligndata %f6, %f4, %f0
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE(std, %f0, %o0))
bne,pt %icc, 1b
add %o0, 0x8, %o0
/* Destination is 64-byte aligned. */
3:
membar #LoadStore | #StoreStore | #StoreLoad
subcc %o2, 0x40, %GLOBAL_SPARE
add %o1, %g1, %g1
andncc %GLOBAL_SPARE, (0x40 - 1), %GLOBAL_SPARE
srl %g1, 3, %g2
sub %o2, %GLOBAL_SPARE, %g3
andn %o1, (0x40 - 1), %o1
and %g2, 7, %g2
andncc %g3, 0x7, %g3
fsrc2 %f0, %f2
sub %g3, 0x8, %g3
sub %o2, %GLOBAL_SPARE, %o2
add %g1, %GLOBAL_SPARE, %g1
subcc %o2, %g3, %o2
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD_BLK(%o1, %f0))
add %o1, 0x40, %o1
add %g1, %g3, %g1
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD_BLK(%o1, %f16))
add %o1, 0x40, %o1
sub %GLOBAL_SPARE, 0x80, %GLOBAL_SPARE
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD_BLK(%o1, %f32))
add %o1, 0x40, %o1
/* There are 8 instances of the unrolled loop,
* one for each possible alignment of the
* source buffer. Each loop instance is 452
* bytes.
*/
sll %g2, 3, %o3
sub %o3, %g2, %o3
sllx %o3, 4, %o3
add %o3, %g2, %o3
sllx %o3, 2, %g2
1: rd %pc, %o3
add %o3, %lo(1f - 1b), %o3
jmpl %o3 + %g2, %g0
nop
.align 64
1: FREG_FROB(f0, f2, f4, f6, f8, f10,f12,f14,f16)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f16,f18,f20,f22,f24,f26,f28,f30,f32)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f32,f34,f36,f38,f40,f42,f44,f46,f0)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f0, %f2, %f48
1: FREG_FROB(f16,f18,f20,f22,f24,f26,f28,f30,f32)
STORE_SYNC(o0, f48)
FREG_FROB(f32,f34,f36,f38,f40,f42,f44,f46,f0)
STORE_JUMP(o0, f48, 40f)
2: FREG_FROB(f32,f34,f36,f38,f40,f42,f44,f46,f0)
STORE_SYNC(o0, f48)
FREG_FROB(f0, f2, f4, f6, f8, f10,f12,f14,f16)
STORE_JUMP(o0, f48, 48f)
3: FREG_FROB(f0, f2, f4, f6, f8, f10,f12,f14,f16)
STORE_SYNC(o0, f48)
FREG_FROB(f16,f18,f20,f22,f24,f26,f28,f30,f32)
STORE_JUMP(o0, f48, 56f)
1: FREG_FROB(f2, f4, f6, f8, f10,f12,f14,f16,f18)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f18,f20,f22,f24,f26,f28,f30,f32,f34)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f34,f36,f38,f40,f42,f44,f46,f0, f2)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f2, %f4, %f48
1: FREG_FROB(f18,f20,f22,f24,f26,f28,f30,f32,f34)
STORE_SYNC(o0, f48)
FREG_FROB(f34,f36,f38,f40,f42,f44,f46,f0, f2)
STORE_JUMP(o0, f48, 41f)
2: FREG_FROB(f34,f36,f38,f40,f42,f44,f46,f0, f2)
STORE_SYNC(o0, f48)
FREG_FROB(f2, f4, f6, f8, f10,f12,f14,f16,f18)
STORE_JUMP(o0, f48, 49f)
3: FREG_FROB(f2, f4, f6, f8, f10,f12,f14,f16,f18)
STORE_SYNC(o0, f48)
FREG_FROB(f18,f20,f22,f24,f26,f28,f30,f32,f34)
STORE_JUMP(o0, f48, 57f)
1: FREG_FROB(f4, f6, f8, f10,f12,f14,f16,f18,f20)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f20,f22,f24,f26,f28,f30,f32,f34,f36)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f36,f38,f40,f42,f44,f46,f0, f2, f4)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f4, %f6, %f48
1: FREG_FROB(f20,f22,f24,f26,f28,f30,f32,f34,f36)
STORE_SYNC(o0, f48)
FREG_FROB(f36,f38,f40,f42,f44,f46,f0, f2, f4)
STORE_JUMP(o0, f48, 42f)
2: FREG_FROB(f36,f38,f40,f42,f44,f46,f0, f2, f4)
STORE_SYNC(o0, f48)
FREG_FROB(f4, f6, f8, f10,f12,f14,f16,f18,f20)
STORE_JUMP(o0, f48, 50f)
3: FREG_FROB(f4, f6, f8, f10,f12,f14,f16,f18,f20)
STORE_SYNC(o0, f48)
FREG_FROB(f20,f22,f24,f26,f28,f30,f32,f34,f36)
STORE_JUMP(o0, f48, 58f)
1: FREG_FROB(f6, f8, f10,f12,f14,f16,f18,f20,f22)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f22,f24,f26,f28,f30,f32,f34,f36,f38)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f38,f40,f42,f44,f46,f0, f2, f4, f6)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f6, %f8, %f48
1: FREG_FROB(f22,f24,f26,f28,f30,f32,f34,f36,f38)
STORE_SYNC(o0, f48)
FREG_FROB(f38,f40,f42,f44,f46,f0, f2, f4, f6)
STORE_JUMP(o0, f48, 43f)
2: FREG_FROB(f38,f40,f42,f44,f46,f0, f2, f4, f6)
STORE_SYNC(o0, f48)
FREG_FROB(f6, f8, f10,f12,f14,f16,f18,f20,f22)
STORE_JUMP(o0, f48, 51f)
3: FREG_FROB(f6, f8, f10,f12,f14,f16,f18,f20,f22)
STORE_SYNC(o0, f48)
FREG_FROB(f22,f24,f26,f28,f30,f32,f34,f36,f38)
STORE_JUMP(o0, f48, 59f)
1: FREG_FROB(f8, f10,f12,f14,f16,f18,f20,f22,f24)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f24,f26,f28,f30,f32,f34,f36,f38,f40)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f40,f42,f44,f46,f0, f2, f4, f6, f8)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f8, %f10, %f48
1: FREG_FROB(f24,f26,f28,f30,f32,f34,f36,f38,f40)
STORE_SYNC(o0, f48)
FREG_FROB(f40,f42,f44,f46,f0, f2, f4, f6, f8)
STORE_JUMP(o0, f48, 44f)
2: FREG_FROB(f40,f42,f44,f46,f0, f2, f4, f6, f8)
STORE_SYNC(o0, f48)
FREG_FROB(f8, f10,f12,f14,f16,f18,f20,f22,f24)
STORE_JUMP(o0, f48, 52f)
3: FREG_FROB(f8, f10,f12,f14,f16,f18,f20,f22,f24)
STORE_SYNC(o0, f48)
FREG_FROB(f24,f26,f28,f30,f32,f34,f36,f38,f40)
STORE_JUMP(o0, f48, 60f)
1: FREG_FROB(f10,f12,f14,f16,f18,f20,f22,f24,f26)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f26,f28,f30,f32,f34,f36,f38,f40,f42)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f42,f44,f46,f0, f2, f4, f6, f8, f10)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f10, %f12, %f48
1: FREG_FROB(f26,f28,f30,f32,f34,f36,f38,f40,f42)
STORE_SYNC(o0, f48)
FREG_FROB(f42,f44,f46,f0, f2, f4, f6, f8, f10)
STORE_JUMP(o0, f48, 45f)
2: FREG_FROB(f42,f44,f46,f0, f2, f4, f6, f8, f10)
STORE_SYNC(o0, f48)
FREG_FROB(f10,f12,f14,f16,f18,f20,f22,f24,f26)
STORE_JUMP(o0, f48, 53f)
3: FREG_FROB(f10,f12,f14,f16,f18,f20,f22,f24,f26)
STORE_SYNC(o0, f48)
FREG_FROB(f26,f28,f30,f32,f34,f36,f38,f40,f42)
STORE_JUMP(o0, f48, 61f)
1: FREG_FROB(f12,f14,f16,f18,f20,f22,f24,f26,f28)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f28,f30,f32,f34,f36,f38,f40,f42,f44)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f44,f46,f0, f2, f4, f6, f8, f10,f12)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f12, %f14, %f48
1: FREG_FROB(f28,f30,f32,f34,f36,f38,f40,f42,f44)
STORE_SYNC(o0, f48)
FREG_FROB(f44,f46,f0, f2, f4, f6, f8, f10,f12)
STORE_JUMP(o0, f48, 46f)
2: FREG_FROB(f44,f46,f0, f2, f4, f6, f8, f10,f12)
STORE_SYNC(o0, f48)
FREG_FROB(f12,f14,f16,f18,f20,f22,f24,f26,f28)
STORE_JUMP(o0, f48, 54f)
3: FREG_FROB(f12,f14,f16,f18,f20,f22,f24,f26,f28)
STORE_SYNC(o0, f48)
FREG_FROB(f28,f30,f32,f34,f36,f38,f40,f42,f44)
STORE_JUMP(o0, f48, 62f)
1: FREG_FROB(f14,f16,f18,f20,f22,f24,f26,f28,f30)
LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
FREG_FROB(f30,f32,f34,f36,f38,f40,f42,f44,f46)
LOOP_CHUNK2(o1, o0, GLOBAL_SPARE, 2f)
FREG_FROB(f46,f0, f2, f4, f6, f8, f10,f12,f14)
LOOP_CHUNK3(o1, o0, GLOBAL_SPARE, 3f)
ba,pt %xcc, 1b+4
faligndata %f14, %f16, %f48
1: FREG_FROB(f30,f32,f34,f36,f38,f40,f42,f44,f46)
STORE_SYNC(o0, f48)
FREG_FROB(f46,f0, f2, f4, f6, f8, f10,f12,f14)
STORE_JUMP(o0, f48, 47f)
2: FREG_FROB(f46,f0, f2, f4, f6, f8, f10,f12,f14)
STORE_SYNC(o0, f48)
FREG_FROB(f14,f16,f18,f20,f22,f24,f26,f28,f30)
STORE_JUMP(o0, f48, 55f)
3: FREG_FROB(f14,f16,f18,f20,f22,f24,f26,f28,f30)
STORE_SYNC(o0, f48)
FREG_FROB(f30,f32,f34,f36,f38,f40,f42,f44,f46)
STORE_JUMP(o0, f48, 63f)
40: FINISH_VISCHUNK(o0, f0, f2, g3)
41: FINISH_VISCHUNK(o0, f2, f4, g3)
42: FINISH_VISCHUNK(o0, f4, f6, g3)
43: FINISH_VISCHUNK(o0, f6, f8, g3)
44: FINISH_VISCHUNK(o0, f8, f10, g3)
45: FINISH_VISCHUNK(o0, f10, f12, g3)
46: FINISH_VISCHUNK(o0, f12, f14, g3)
47: UNEVEN_VISCHUNK(o0, f14, f0, g3)
48: FINISH_VISCHUNK(o0, f16, f18, g3)
49: FINISH_VISCHUNK(o0, f18, f20, g3)
50: FINISH_VISCHUNK(o0, f20, f22, g3)
51: FINISH_VISCHUNK(o0, f22, f24, g3)
52: FINISH_VISCHUNK(o0, f24, f26, g3)
53: FINISH_VISCHUNK(o0, f26, f28, g3)
54: FINISH_VISCHUNK(o0, f28, f30, g3)
55: UNEVEN_VISCHUNK(o0, f30, f0, g3)
56: FINISH_VISCHUNK(o0, f32, f34, g3)
57: FINISH_VISCHUNK(o0, f34, f36, g3)
58: FINISH_VISCHUNK(o0, f36, f38, g3)
59: FINISH_VISCHUNK(o0, f38, f40, g3)
60: FINISH_VISCHUNK(o0, f40, f42, g3)
61: FINISH_VISCHUNK(o0, f42, f44, g3)
62: FINISH_VISCHUNK(o0, f44, f46, g3)
63: UNEVEN_VISCHUNK_LAST(o0, f46, f0, g3)
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
93: EX_LD_FP(LOAD(ldd, %o1, %f2))
add %o1, 8, %o1
subcc %g3, 8, %g3
faligndata %f0, %f2, %f8
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE(std, %f8, %o0))
bl,pn %xcc, 95f
add %o0, 8, %o0
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_LD_FP(LOAD(ldd, %o1, %f0))
add %o1, 8, %o1
subcc %g3, 8, %g3
faligndata %f2, %f0, %f8
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE(std, %f8, %o0))
bge,pt %xcc, 93b
add %o0, 8, %o0
95: brz,pt %o2, 2f
mov %g1, %o1
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
1: EX_LD_FP(LOAD(ldub, %o1, %o3))
add %o1, 1, %o1
subcc %o2, 1, %o2
sparc64: fix FP corruption in user copy functions Short story: Exception handlers used by some copy_to_user() and copy_from_user() functions do not diligently clean up floating point register usage, and this can result in a user process seeing invalid values in floating point registers. This sometimes makes the process fail. Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions use floating point registers and VIS alignaddr/faligndata to accelerate data copying when source and dest addresses don't align well. Linux uses a lazy scheme for saving floating point registers; It is not done upon entering the kernel since it's a very expensive operation. Rather, it is done only when needed. If the kernel ends up not using FP regs during the course of some trap or system call, then it can return to user space without saving or restoring them. The various memcpy functions begin their FP code with VISEntry (or a variation thereof), which saves the FP regs. They conclude their FP code with VISExit (or a variation) which essentially marks the FP regs "clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned off so that a lazy restore will be triggered when/if the user process accesses floating point regs again. The bug is that the user copy variants of memcpy, copy_from_user() and copy_to_user(), employ an exception handling mechanism to detect faults when accessing user space addresses, and when this handler is invoked, an immediate return from the function is forced, and VISExit is not executed, thus leaving the fprs register in an indeterminate state, but often with fprs.FPRS_FEF set and one or more dirty bits. This results in a return to user space with invalid values in the FP regs, and since fprs.FPRS_FEF is on, no lazy restore occurs. This bug affects copy_to_user() and copy_from_user() for NG4, NG2, U3, and U1. All are fixed by using a new exception handler for those loads and stores that are done during the time between VISEnter and VISExit. n.b. In NG4memcpy, the problematic code can be triggered by a copy size greater than 128 bytes and an unaligned source address. This bug is known to be the cause of random user process memory corruptions while perf is running with the callgraph option (ie, perf record -g). This occurs because perf uses copy_from_user() to read user stacks, and may fault when it follows a stack frame pointer off to an invalid page. Validation checks on the stack address just obscure the underlying problem. Signed-off-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 13:24:49 +07:00
EX_ST_FP(STORE(stb, %o3, %o0))
bne,pt %xcc, 1b
add %o0, 1, %o0
2: membar #StoreLoad | #StoreStore
VISExit
retl
mov EX_RETVAL(%o4), %o0
.align 64
70: /* 16 < len <= (5 * 64) */
bne,pn %XCC, 75f
sub %o0, %o1, %o3
72: andn %o2, 0xf, %GLOBAL_SPARE
and %o2, 0xf, %o2
1: EX_LD(LOAD(ldx, %o1 + 0x00, %o5))
EX_LD(LOAD(ldx, %o1 + 0x08, %g1))
subcc %GLOBAL_SPARE, 0x10, %GLOBAL_SPARE
EX_ST(STORE(stx, %o5, %o1 + %o3))
add %o1, 0x8, %o1
EX_ST(STORE(stx, %g1, %o1 + %o3))
bgu,pt %XCC, 1b
add %o1, 0x8, %o1
73: andcc %o2, 0x8, %g0
be,pt %XCC, 1f
nop
EX_LD(LOAD(ldx, %o1, %o5))
sub %o2, 0x8, %o2
EX_ST(STORE(stx, %o5, %o1 + %o3))
add %o1, 0x8, %o1
1: andcc %o2, 0x4, %g0
be,pt %XCC, 1f
nop
EX_LD(LOAD(lduw, %o1, %o5))
sub %o2, 0x4, %o2
EX_ST(STORE(stw, %o5, %o1 + %o3))
add %o1, 0x4, %o1
1: cmp %o2, 0
be,pt %XCC, 85f
nop
ba,pt %xcc, 90f
nop
75: andcc %o0, 0x7, %g1
sub %g1, 0x8, %g1
be,pn %icc, 2f
sub %g0, %g1, %g1
sub %o2, %g1, %o2
1: EX_LD(LOAD(ldub, %o1, %o5))
subcc %g1, 1, %g1
EX_ST(STORE(stb, %o5, %o1 + %o3))
bgu,pt %icc, 1b
add %o1, 1, %o1
2: add %o1, %o3, %o0
andcc %o1, 0x7, %g1
bne,pt %icc, 8f
sll %g1, 3, %g1
cmp %o2, 16
bgeu,pt %icc, 72b
nop
ba,a,pt %xcc, 73b
8: mov 64, %o3
andn %o1, 0x7, %o1
EX_LD(LOAD(ldx, %o1, %g2))
sub %o3, %g1, %o3
andn %o2, 0x7, %GLOBAL_SPARE
sllx %g2, %g1, %g2
1: EX_LD(LOAD(ldx, %o1 + 0x8, %g3))
subcc %GLOBAL_SPARE, 0x8, %GLOBAL_SPARE
add %o1, 0x8, %o1
srlx %g3, %o3, %o5
or %o5, %g2, %o5
EX_ST(STORE(stx, %o5, %o0))
add %o0, 0x8, %o0
bgu,pt %icc, 1b
sllx %g3, %g1, %g2
srl %g1, 3, %g1
andcc %o2, 0x7, %o2
be,pn %icc, 85f
add %o1, %g1, %o1
ba,pt %xcc, 90f
sub %o0, %o1, %o3
.align 64
80: /* 0 < len <= 16 */
andcc %o3, 0x3, %g0
bne,pn %XCC, 90f
sub %o0, %o1, %o3
1: EX_LD(LOAD(lduw, %o1, %g1))
subcc %o2, 4, %o2
EX_ST(STORE(stw, %g1, %o1 + %o3))
bgu,pt %XCC, 1b
add %o1, 4, %o1
85: retl
mov EX_RETVAL(%o4), %o0
.align 32
90: EX_LD(LOAD(ldub, %o1, %g1))
subcc %o2, 1, %o2
EX_ST(STORE(stb, %g1, %o1 + %o3))
bgu,pt %XCC, 90b
add %o1, 1, %o1
retl
mov EX_RETVAL(%o4), %o0
.size FUNC_NAME, .-FUNC_NAME