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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: sw@weilnetz.de, mark.cave-ayland@ilande.co.uk, qemu-stable@nongnu.org
Subject: [PATCH 1/2] tcg/sparc: Fix temp_allocate_frame vs sparc stack bias
Date: Fri, 18 Jun 2021 21:56:59 -0700	[thread overview]
Message-ID: <20210619045700.46907-2-richard.henderson@linaro.org> (raw)
In-Reply-To: <20210619045700.46907-1-richard.henderson@linaro.org>

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
Cc: mark.cave-ayland@ilande.co.uk
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(-)

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;
-- 
2.25.1



  reply	other threads:[~2021-06-19  4:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-19  4:56 [PATCH 0/2] tcg: Fixes for temp_allocate_frame Richard Henderson
2021-06-19  4:56 ` Richard Henderson [this message]
2021-06-19  4:57 ` [PATCH 2/2] tcg: Allocate sufficient storage in temp_allocate_frame Richard Henderson
2021-06-19  9:41   ` Philippe Mathieu-Daudé
2021-06-19  8:16 ` [PATCH 0/2] tcg: Fixes for temp_allocate_frame Stefan Weil
2021-06-21  8:42   ` Daniel P. Berrangé

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