| Message ID | 20210619134216.590423-2-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | tcg: Fixes for temp_allocate_frame | expand |
On 6/19/21 3:42 PM, Richard Henderson wrote: > We should not be aligning the offset in temp_allocate_frame, > because the odd offset produces an aligned address in the end. > Instead, pass the logical offset into tcg_set_frame and add > the stack bias last. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > tcg/tcg.c | 9 +++------ > tcg/sparc/tcg-target.c.inc | 16 ++++++++++------ > 2 files changed, 13 insertions(+), 12 deletions(-) LGTM but I'd rather have another review... Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > diff --git a/tcg/tcg.c b/tcg/tcg.c > index dd584f3bba..52e858523c 100644 > --- a/tcg/tcg.c > +++ b/tcg/tcg.c > @@ -3015,17 +3015,14 @@ static void check_regs(TCGContext *s) > > static void temp_allocate_frame(TCGContext *s, TCGTemp *ts) > { > -#if !(defined(__sparc__) && TCG_TARGET_REG_BITS == 64) > - /* Sparc64 stack is accessed with offset of 2047 */ > - s->current_frame_offset = (s->current_frame_offset + > - (tcg_target_long)sizeof(tcg_target_long) - 1) & > - ~(sizeof(tcg_target_long) - 1); > -#endif > if (s->current_frame_offset + (tcg_target_long)sizeof(tcg_target_long) > > s->frame_end) { > tcg_abort(); > } > ts->mem_offset = s->current_frame_offset; > +#if defined(__sparc__) > + ts->mem_offset += TCG_TARGET_STACK_BIAS; > +#endif > ts->mem_base = s->frame_temp; > ts->mem_allocated = 1; > s->current_frame_offset += sizeof(tcg_target_long); > diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc > index ce39ac2d86..a6ec94a094 100644 > --- a/tcg/sparc/tcg-target.c.inc > +++ b/tcg/sparc/tcg-target.c.inc > @@ -984,14 +984,18 @@ static void tcg_target_qemu_prologue(TCGContext *s) > { > int tmp_buf_size, frame_size; > > - /* The TCG temp buffer is at the top of the frame, immediately > - below the frame pointer. */ > + /* > + * The TCG temp buffer is at the top of the frame, immediately > + * below the frame pointer. Use the logical (aligned) offset here; > + * the stack bias is applied in temp_allocate_frame(). > + */ > tmp_buf_size = CPU_TEMP_BUF_NLONGS * (int)sizeof(long); > - tcg_set_frame(s, TCG_REG_I6, TCG_TARGET_STACK_BIAS - tmp_buf_size, > - tmp_buf_size); > + tcg_set_frame(s, TCG_REG_I6, -tmp_buf_size, tmp_buf_size); > > - /* TCG_TARGET_CALL_STACK_OFFSET includes the stack bias, but is > - otherwise the minimal frame usable by callees. */ > + /* > + * TCG_TARGET_CALL_STACK_OFFSET includes the stack bias, but is > + * otherwise the minimal frame usable by callees. > + */ > frame_size = TCG_TARGET_CALL_STACK_OFFSET - TCG_TARGET_STACK_BIAS; > frame_size += TCG_STATIC_CALL_ARGS_SIZE + tmp_buf_size; > frame_size += TCG_TARGET_STACK_ALIGN - 1; >
diff --git a/tcg/tcg.c b/tcg/tcg.c index dd584f3bba..52e858523c 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -3015,17 +3015,14 @@ static void check_regs(TCGContext *s) static void temp_allocate_frame(TCGContext *s, TCGTemp *ts) { -#if !(defined(__sparc__) && TCG_TARGET_REG_BITS == 64) - /* Sparc64 stack is accessed with offset of 2047 */ - s->current_frame_offset = (s->current_frame_offset + - (tcg_target_long)sizeof(tcg_target_long) - 1) & - ~(sizeof(tcg_target_long) - 1); -#endif if (s->current_frame_offset + (tcg_target_long)sizeof(tcg_target_long) > s->frame_end) { tcg_abort(); } ts->mem_offset = s->current_frame_offset; +#if defined(__sparc__) + ts->mem_offset += TCG_TARGET_STACK_BIAS; +#endif ts->mem_base = s->frame_temp; ts->mem_allocated = 1; s->current_frame_offset += sizeof(tcg_target_long); diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc index ce39ac2d86..a6ec94a094 100644 --- a/tcg/sparc/tcg-target.c.inc +++ b/tcg/sparc/tcg-target.c.inc @@ -984,14 +984,18 @@ static void tcg_target_qemu_prologue(TCGContext *s) { int tmp_buf_size, frame_size; - /* The TCG temp buffer is at the top of the frame, immediately - below the frame pointer. */ + /* + * The TCG temp buffer is at the top of the frame, immediately + * below the frame pointer. Use the logical (aligned) offset here; + * the stack bias is applied in temp_allocate_frame(). + */ tmp_buf_size = CPU_TEMP_BUF_NLONGS * (int)sizeof(long); - tcg_set_frame(s, TCG_REG_I6, TCG_TARGET_STACK_BIAS - tmp_buf_size, - tmp_buf_size); + tcg_set_frame(s, TCG_REG_I6, -tmp_buf_size, tmp_buf_size); - /* TCG_TARGET_CALL_STACK_OFFSET includes the stack bias, but is - otherwise the minimal frame usable by callees. */ + /* + * TCG_TARGET_CALL_STACK_OFFSET includes the stack bias, but is + * otherwise the minimal frame usable by callees. + */ frame_size = TCG_TARGET_CALL_STACK_OFFSET - TCG_TARGET_STACK_BIAS; frame_size += TCG_STATIC_CALL_ARGS_SIZE + tmp_buf_size; frame_size += TCG_TARGET_STACK_ALIGN - 1;
We should not be aligning the offset in temp_allocate_frame, because the odd offset produces an aligned address in the end. Instead, pass the logical offset into tcg_set_frame and add the stack bias last. Cc: qemu-stable@nongnu.org Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- tcg/tcg.c | 9 +++------ tcg/sparc/tcg-target.c.inc | 16 ++++++++++------ 2 files changed, 13 insertions(+), 12 deletions(-)