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parisc: fix bugs in pa_memcpy

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The patch 554bfeceb8a22d448cd986fc9efce25e833278a1 ("parisc: Fix access
fault handling in pa_memcpy()") reimplements the pa_memcpy function.
Unfortunatelly, it makes the kernel unbootable. The crash happens in the
function ide_complete_cmd where memcpy is called with the same source
and destination address.

This patch fixes a few bugs in pa_memcpy:

* When jumping to .Lcopy_loop_16 for the first time, don't skip the
  instruction "ldi 31,t0" (this bug made the kernel unbootable)
* Use the COND macro when comparing length, so that the comparison is
  64-bit (a theoretical issue, in case the length is greater than
  0xffffffff)
* Don't use the COND macro after the "extru" instruction (the PA-RISC
  specification says that the upper 32-bits of extru result are undefined,
  although they are set to zero in practice)
* Fix exception addresses in .Lcopy16_fault and .Lcopy8_fault
* Rename .Lcopy_loop_4 to .Lcopy_loop_8 (so that it is consistent with
  .Lcopy8_fault)

Cc: <stable@vger.kernel.org> # v4.9+
Fixes: 554bfeceb8a2 ("parisc: Fix access fault handling in pa_memcpy()")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Mikulas Patocka 2017-04-14 14:15:20 -04:00 committed by Helge Deller
parent 1bf4b1268e
commit 409c1b250e
1 changed files with 14 additions and 13 deletions
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27
arch/parisc/lib/lusercopy.S
View File

@ -201,7 +201,7 @@ ENTRY_CFI(pa_memcpy)
add dst,len,end
/* short copy with less than 16 bytes? */
cmpib,>>=,n 15,len,.Lbyte_loop
cmpib,COND(>>=),n 15,len,.Lbyte_loop
/* same alignment? */
xor src,dst,t0
@ -216,7 +216,7 @@ ENTRY_CFI(pa_memcpy)
/* loop until we are 64-bit aligned */
.Lalign_loop64:
extru dst,31,3,t1
cmpib,=,n 0,t1,.Lcopy_loop_16
cmpib,=,n 0,t1,.Lcopy_loop_16_start
20: ldb,ma 1(srcspc,src),t1
21: stb,ma t1,1(dstspc,dst)
b .Lalign_loop64
@ -225,6 +225,7 @@ ENTRY_CFI(pa_memcpy)
ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
.Lcopy_loop_16_start:
ldi 31,t0
.Lcopy_loop_16:
cmpb,COND(>>=),n t0,len,.Lword_loop
@ -267,7 +268,7 @@ ENTRY_CFI(pa_memcpy)
/* loop until we are 32-bit aligned */
.Lalign_loop32:
extru dst,31,2,t1
cmpib,=,n 0,t1,.Lcopy_loop_4
cmpib,=,n 0,t1,.Lcopy_loop_8
20: ldb,ma 1(srcspc,src),t1
21: stb,ma t1,1(dstspc,dst)
b .Lalign_loop32
@ -277,7 +278,7 @@ ENTRY_CFI(pa_memcpy)
ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
.Lcopy_loop_4:
.Lcopy_loop_8:
cmpib,COND(>>=),n 15,len,.Lbyte_loop
10: ldw 0(srcspc,src),t1
@ -299,7 +300,7 @@ ENTRY_CFI(pa_memcpy)
ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done)
ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done)
b .Lcopy_loop_4
b .Lcopy_loop_8
ldo -16(len),len
.Lbyte_loop:
@ -324,7 +325,7 @@ ENTRY_CFI(pa_memcpy)
.Lunaligned_copy:
/* align until dst is 32bit-word-aligned */
extru dst,31,2,t1
cmpib,COND(=),n 0,t1,.Lcopy_dstaligned
cmpib,=,n 0,t1,.Lcopy_dstaligned
20: ldb 0(srcspc,src),t1
ldo 1(src),src
21: stb,ma t1,1(dstspc,dst)
@ -362,7 +363,7 @@ ENTRY_CFI(pa_memcpy)
cmpiclr,<> 1,t0,%r0
b,n .Lcase1
.Lcase0:
cmpb,= %r0,len,.Lcda_finish
cmpb,COND(=) %r0,len,.Lcda_finish
nop
1: ldw,ma 4(srcspc,src), a3
@ -376,7 +377,7 @@ ENTRY_CFI(pa_memcpy)
1: ldw,ma 4(srcspc,src), a3
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
ldo -1(len),len
cmpb,=,n %r0,len,.Ldo0
cmpb,COND(=),n %r0,len,.Ldo0
.Ldo4:
1: ldw,ma 4(srcspc,src), a0
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
@ -402,7 +403,7 @@ ENTRY_CFI(pa_memcpy)
1: stw,ma t0, 4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
ldo -4(len),len
cmpb,<> %r0,len,.Ldo4
cmpb,COND(<>) %r0,len,.Ldo4
nop
.Ldo0:
shrpw a2, a3, %sar, t0
@ -436,14 +437,14 @@ ENTRY_CFI(pa_memcpy)
/* fault exception fixup handlers: */
#ifdef CONFIG_64BIT
.Lcopy16_fault:
10: b .Lcopy_done
std,ma t1,8(dstspc,dst)
b .Lcopy_done
10: std,ma t1,8(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
#endif
.Lcopy8_fault:
10: b .Lcopy_done
stw,ma t1,4(dstspc,dst)
b .Lcopy_done
10: stw,ma t1,4(dstspc,dst)
ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
.exit