From 409c1b250e30ad0e48b4d15d7319b4e18c046c4f Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 14 Apr 2017 14:15:20 -0400 Subject: [PATCH] parisc: fix bugs in pa_memcpy 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: # v4.9+ Fixes: 554bfeceb8a2 ("parisc: Fix access fault handling in pa_memcpy()") Signed-off-by: Mikulas Patocka Signed-off-by: Helge Deller --- arch/parisc/lib/lusercopy.S | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/arch/parisc/lib/lusercopy.S b/arch/parisc/lib/lusercopy.S index f01188c044ee..85c28bb80fb7 100644 --- a/arch/parisc/lib/lusercopy.S +++ b/arch/parisc/lib/lusercopy.S @@ -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 -- 2.20.1