From: Helge Deller deller@gmx.de
commit dd2288f4a020d693360e3e8d72f8b9d9c25f5ef6 upstream.
Usually the kernel provides fixup routines to emulate the fldd and fstd floating-point instructions if they load or store 8-byte from/to a not natuarally aligned memory location.
On a 32-bit kernel I noticed that those unaligned handlers didn't worked and instead the application got a SEGV. While checking the code I found two problems:
First, the OPCODE_FLDD_L and OPCODE_FSTD_L cases were ifdef'ed out by the CONFIG_PA20 option, and as such those weren't built on a pure 32-bit kernel. This is now fixed by moving the CONFIG_PA20 #ifdef to prevent the compilation of OPCODE_LDD_L and OPCODE_FSTD_L only, and handling the fldd and fstd instructions.
The second problem are two bugs in the 32-bit inline assembly code, where the wrong registers where used. The calculation of the natural alignment used %2 (vall) instead of %3 (ior), and the first word was stored back to address %1 (valh) instead of %3 (ior).
Signed-off-by: Helge Deller deller@gmx.de Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/parisc/kernel/unaligned.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/arch/parisc/kernel/unaligned.c +++ b/arch/parisc/kernel/unaligned.c @@ -411,7 +411,7 @@ static int emulate_std(struct pt_regs *r __asm__ __volatile__ ( " mtsp %4, %%sr1\n" " zdep %2, 29, 2, %%r19\n" -" dep %%r0, 31, 2, %2\n" +" dep %%r0, 31, 2, %3\n" " mtsar %%r19\n" " zvdepi -2, 32, %%r19\n" "1: ldw 0(%%sr1,%3),%%r20\n" @@ -423,7 +423,7 @@ static int emulate_std(struct pt_regs *r " andcm %%r21, %%r19, %%r21\n" " or %1, %%r20, %1\n" " or %2, %%r21, %2\n" -"3: stw %1,0(%%sr1,%1)\n" +"3: stw %1,0(%%sr1,%3)\n" "4: stw %%r1,4(%%sr1,%3)\n" "5: stw %2,8(%%sr1,%3)\n" " copy %%r0, %0\n" @@ -611,7 +611,6 @@ void handle_unaligned(struct pt_regs *re ret = ERR_NOTHANDLED; /* "undefined", but lets kill them. */ break; } -#ifdef CONFIG_PA20 switch (regs->iir & OPCODE2_MASK) { case OPCODE_FLDD_L: @@ -622,14 +621,15 @@ void handle_unaligned(struct pt_regs *re flop=1; ret = emulate_std(regs, R2(regs->iir),1); break; +#ifdef CONFIG_PA20 case OPCODE_LDD_L: ret = emulate_ldd(regs, R2(regs->iir),0); break; case OPCODE_STD_L: ret = emulate_std(regs, R2(regs->iir),0); break; - } #endif + } switch (regs->iir & OPCODE3_MASK) { case OPCODE_FLDW_L: