Compiling kernel with -Warray-bounds throws below warning: In function 'emulate_vsx_store': warning: array subscript is above array bounds [-Warray-bounds] buf.d[2] = byterev_8(reg->d[1]); ~~~~~^~~ buf.d[3] = byterev_8(reg->d[0]); ~~~~~^~~
Fix it by converting local variable 'union vsx_reg buf' into an array. Also consider function argument 'union vsx_reg *reg' as array instead of pointer because callers are actually passing an array to it. Fixes: af99da74333b ("powerpc/sstep: Support VSX vector paired storage access instructions") Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com> --- arch/powerpc/lib/sstep.c | 61 ++++++++++++++++++++-------------------- 1 file changed, 31 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index bf7a7d62ae8b..5b4281ade5b6 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -723,7 +723,8 @@ void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg, const unsigned char *bp; size = GETSIZE(op->type); - reg->d[0] = reg->d[1] = 0; + reg[0].d[0] = reg[0].d[1] = 0; + reg[1].d[0] = reg[1].d[1] = 0; switch (op->element_size) { case 32: @@ -742,25 +743,25 @@ void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg, /* scalar loads, lxvd2x, lxvdsx */ read_size = (size >= 8) ? 8 : size; i = IS_LE ? 8 : 8 - read_size; - memcpy(®->b[i], mem, read_size); + memcpy(®[0].b[i], mem, read_size); if (rev) - do_byte_reverse(®->b[i], 8); + do_byte_reverse(®[0].b[i], 8); if (size < 8) { if (op->type & SIGNEXT) { /* size == 4 is the only case here */ - reg->d[IS_LE] = (signed int) reg->d[IS_LE]; + reg[0].d[IS_LE] = (signed int)reg[0].d[IS_LE]; } else if (op->vsx_flags & VSX_FPCONV) { preempt_disable(); - conv_sp_to_dp(®->fp[1 + IS_LE], - ®->dp[IS_LE]); + conv_sp_to_dp(®[0].fp[1 + IS_LE], + ®[0].dp[IS_LE]); preempt_enable(); } } else { if (size == 16) { unsigned long v = *(unsigned long *)(mem + 8); - reg->d[IS_BE] = !rev ? v : byterev_8(v); + reg[0].d[IS_BE] = !rev ? v : byterev_8(v); } else if (op->vsx_flags & VSX_SPLAT) - reg->d[IS_BE] = reg->d[IS_LE]; + reg[0].d[IS_BE] = reg[0].d[IS_LE]; } break; case 4: @@ -768,13 +769,13 @@ void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg, wp = mem; for (j = 0; j < size / 4; ++j) { i = IS_LE ? 3 - j : j; - reg->w[i] = !rev ? *wp++ : byterev_4(*wp++); + reg[0].w[i] = !rev ? *wp++ : byterev_4(*wp++); } if (op->vsx_flags & VSX_SPLAT) { - u32 val = reg->w[IS_LE ? 3 : 0]; + u32 val = reg[0].w[IS_LE ? 3 : 0]; for (; j < 4; ++j) { i = IS_LE ? 3 - j : j; - reg->w[i] = val; + reg[0].w[i] = val; } } break; @@ -783,7 +784,7 @@ void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg, hp = mem; for (j = 0; j < size / 2; ++j) { i = IS_LE ? 7 - j : j; - reg->h[i] = !rev ? *hp++ : byterev_2(*hp++); + reg[0].h[i] = !rev ? *hp++ : byterev_2(*hp++); } break; case 1: @@ -791,7 +792,7 @@ void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg, bp = mem; for (j = 0; j < size; ++j) { i = IS_LE ? 15 - j : j; - reg->b[i] = *bp++; + reg[0].b[i] = *bp++; } break; } @@ -804,7 +805,7 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, { int size, write_size; int i, j; - union vsx_reg buf; + union vsx_reg buf[2]; unsigned int *wp; unsigned short *hp; unsigned char *bp; @@ -818,11 +819,11 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, break; if (rev) { /* reverse 32 bytes */ - buf.d[0] = byterev_8(reg->d[3]); - buf.d[1] = byterev_8(reg->d[2]); - buf.d[2] = byterev_8(reg->d[1]); - buf.d[3] = byterev_8(reg->d[0]); - reg = &buf; + buf[0].d[0] = byterev_8(reg[1].d[1]); + buf[0].d[1] = byterev_8(reg[1].d[0]); + buf[1].d[0] = byterev_8(reg[0].d[1]); + buf[1].d[1] = byterev_8(reg[0].d[0]); + reg = buf; } memcpy(mem, reg, size); break; @@ -834,9 +835,9 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, rev = !rev; if (rev) { /* reverse 16 bytes */ - buf.d[0] = byterev_8(reg->d[1]); - buf.d[1] = byterev_8(reg->d[0]); - reg = &buf; + buf[0].d[0] = byterev_8(reg[0].d[1]); + buf[0].d[1] = byterev_8(reg[0].d[0]); + reg = buf; } memcpy(mem, reg, size); break; @@ -845,15 +846,15 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, write_size = (size >= 8) ? 8 : size; i = IS_LE ? 8 : 8 - write_size; if (size < 8 && op->vsx_flags & VSX_FPCONV) { - buf.d[0] = buf.d[1] = 0; + buf[0].d[0] = buf[0].d[1] = 0; preempt_disable(); - conv_dp_to_sp(®->dp[IS_LE], &buf.fp[1 + IS_LE]); + conv_dp_to_sp(®[0].dp[IS_LE], &buf[0].fp[1 + IS_LE]); preempt_enable(); - reg = &buf; + reg = buf; } - memcpy(mem, ®->b[i], write_size); + memcpy(mem, ®[0].b[i], write_size); if (size == 16) - memcpy(mem + 8, ®->d[IS_BE], 8); + memcpy(mem + 8, ®[0].d[IS_BE], 8); if (unlikely(rev)) { do_byte_reverse(mem, write_size); if (size == 16) @@ -865,7 +866,7 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, wp = mem; for (j = 0; j < size / 4; ++j) { i = IS_LE ? 3 - j : j; - *wp++ = !rev ? reg->w[i] : byterev_4(reg->w[i]); + *wp++ = !rev ? reg[0].w[i] : byterev_4(reg[0].w[i]); } break; case 2: @@ -873,7 +874,7 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, hp = mem; for (j = 0; j < size / 2; ++j) { i = IS_LE ? 7 - j : j; - *hp++ = !rev ? reg->h[i] : byterev_2(reg->h[i]); + *hp++ = !rev ? reg[0].h[i] : byterev_2(reg[0].h[i]); } break; case 1: @@ -881,7 +882,7 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, bp = mem; for (j = 0; j < size; ++j) { i = IS_LE ? 15 - j : j; - *bp++ = reg->b[i]; + *bp++ = reg[0].b[i]; } break; } -- 2.26.2