sparc: fix accurate exception reporting in copy_{from,to}_user for M7

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a couple of bad
calculations. This will fix the return value of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

Fixes: 34060b8fffa7 ("arch/sparc: Add accurate exception reporting in M7memcpy")
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # on Oracle SPARC S7
Tested-by: Tony Rodriguez <unixpro1970@gmail.com> # S7, see https://lore.kernel.org/r/98564e2e68df2dda0e00c67a75c7f7dfedb33c7e.camel@physik.fu-berlin.de
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-5-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson <andreas@gaisler.com>

diff --git a/arch/sparc/lib/M7memcpy.S b/arch/sparc/lib/M7memcpy.S
index cbd42ea7c3f7c25a369536eaf8d0b28a808ae5ba..99357bfa8e82ad7cf15dfd04117c89b905082f5b 100644 (file)
--- a/arch/sparc/lib/M7memcpy.S
+++ b/arch/sparc/lib/M7memcpy.S
@@ -696,16 +696,16 @@ FUNC_NAME:
        EX_LD_FP(LOAD(ldd, %o4+40, %f26), memcpy_retl_o2_plus_o5_plus_40)
        faligndata %f24, %f26, %f10
        EX_ST_FP(STORE(std, %f6, %o0+24), memcpy_retl_o2_plus_o5_plus_40)
-       EX_LD_FP(LOAD(ldd, %o4+48, %f28), memcpy_retl_o2_plus_o5_plus_40)
+       EX_LD_FP(LOAD(ldd, %o4+48, %f28), memcpy_retl_o2_plus_o5_plus_32)
        faligndata %f26, %f28, %f12
-       EX_ST_FP(STORE(std, %f8, %o0+32), memcpy_retl_o2_plus_o5_plus_40)
+       EX_ST_FP(STORE(std, %f8, %o0+32), memcpy_retl_o2_plus_o5_plus_32)
        add     %o4, 64, %o4
-       EX_LD_FP(LOAD(ldd, %o4-8, %f30), memcpy_retl_o2_plus_o5_plus_40)
+       EX_LD_FP(LOAD(ldd, %o4-8, %f30), memcpy_retl_o2_plus_o5_plus_24)
        faligndata %f28, %f30, %f14
-       EX_ST_FP(STORE(std, %f10, %o0+40), memcpy_retl_o2_plus_o5_plus_40)
-       EX_ST_FP(STORE(std, %f12, %o0+48), memcpy_retl_o2_plus_o5_plus_40)
+       EX_ST_FP(STORE(std, %f10, %o0+40), memcpy_retl_o2_plus_o5_plus_24)
+       EX_ST_FP(STORE(std, %f12, %o0+48), memcpy_retl_o2_plus_o5_plus_16)
        add     %o0, 64, %o0
-       EX_ST_FP(STORE(std, %f14, %o0-8), memcpy_retl_o2_plus_o5_plus_40)
+       EX_ST_FP(STORE(std, %f14, %o0-8), memcpy_retl_o2_plus_o5_plus_8)
        fsrc2   %f30, %f14
        bgu,pt  %xcc, .Lunalign_sloop
         prefetch [%o4 + (8 * BLOCK_SIZE)], 20
@@ -728,7 +728,7 @@ FUNC_NAME:
        add     %o4, 8, %o4
        faligndata %f0, %f2, %f16
        subcc   %o5, 8, %o5
-       EX_ST_FP(STORE(std, %f16, %o0), memcpy_retl_o2_plus_o5)
+       EX_ST_FP(STORE(std, %f16, %o0), memcpy_retl_o2_plus_o5_plus_8)
        fsrc2   %f2, %f0
        bgu,pt  %xcc, .Lunalign_by8
         add    %o0, 8, %o0
@@ -772,7 +772,7 @@ FUNC_NAME:
        subcc   %o5, 0x20, %o5
        EX_ST(STORE(stx, %o3, %o0 + 0x00), memcpy_retl_o2_plus_o5_plus_32)
        EX_ST(STORE(stx, %g2, %o0 + 0x08), memcpy_retl_o2_plus_o5_plus_24)
-       EX_ST(STORE(stx, %g7, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_24)
+       EX_ST(STORE(stx, %g7, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_16)
        EX_ST(STORE(stx, %o4, %o0 + 0x18), memcpy_retl_o2_plus_o5_plus_8)
        bne,pt  %xcc, 1b
         add    %o0, 0x20, %o0
@@ -804,12 +804,12 @@ FUNC_NAME:
        brz,pt  %o3, 2f
         sub    %o2, %o3, %o2
 
-1:     EX_LD(LOAD(ldub, %o1 + 0x00, %g2), memcpy_retl_o2_plus_g1)
+1:     EX_LD(LOAD(ldub, %o1 + 0x00, %g2), memcpy_retl_o2_plus_o3)
        add     %o1, 1, %o1
        subcc   %o3, 1, %o3
        add     %o0, 1, %o0
        bne,pt  %xcc, 1b
-        EX_ST(STORE(stb, %g2, %o0 - 0x01), memcpy_retl_o2_plus_g1_plus_1)
+        EX_ST(STORE(stb, %g2, %o0 - 0x01), memcpy_retl_o2_plus_o3_plus_1)
 2:
        and     %o1, 0x7, %o3
        brz,pn  %o3, .Lmedium_noprefetch_cp

diff --git a/arch/sparc/lib/Memcpy_utils.S b/arch/sparc/lib/Memcpy_utils.S
index 64fbac28b3db18864b0d067acaee0d7898feec7a..207343367bb2daa41a70398e20ef271116423b38 100644 (file)
--- a/arch/sparc/lib/Memcpy_utils.S
+++ b/arch/sparc/lib/Memcpy_utils.S
@@ -137,6 +137,15 @@ ENTRY(memcpy_retl_o2_plus_63_8)
        ba,pt   %xcc, __restore_asi
         add    %o2, 8, %o0
 ENDPROC(memcpy_retl_o2_plus_63_8)
+ENTRY(memcpy_retl_o2_plus_o3)
+       ba,pt   %xcc, __restore_asi
+        add    %o2, %o3, %o0
+ENDPROC(memcpy_retl_o2_plus_o3)
+ENTRY(memcpy_retl_o2_plus_o3_plus_1)
+       add     %o3, 1, %o3
+       ba,pt   %xcc, __restore_asi
+        add    %o2, %o3, %o0
+ENDPROC(memcpy_retl_o2_plus_o3_plus_1)
 ENTRY(memcpy_retl_o2_plus_o5)
        ba,pt   %xcc, __restore_asi
         add    %o2, %o5, %o0