diff mbox series

[v5,48/67] target/microblaze: Do not set MO_ALIGN for user-only

Message ID 20211015041053.2769193-49-richard.henderson@linaro.org
State Superseded
Headers show
Series user-only: Cleanup SIGSEGV and SIGBUS handling | expand

Commit Message

Richard Henderson Oct. 15, 2021, 4:10 a.m. UTC 
The kernel will fix up unaligned accesses, so emulate that
by allowing unaligned accesses to succeed.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 target/microblaze/translate.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

-- 
2.25.1
diff mbox series

Patch

diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index a14ffed784..ef44bca2fd 100644
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -727,6 +727,7 @@  static TCGv compute_ldst_addr_ea(DisasContext *dc, int ra, int rb)
 }
 #endif
 
+#ifndef CONFIG_USER_ONLY
 static void record_unaligned_ess(DisasContext *dc, int rd,
                                  MemOp size, bool store)
 {
@@ -739,6 +740,7 @@  static void record_unaligned_ess(DisasContext *dc, int rd,
 
     tcg_set_insn_start_param(dc->insn_start, 1, iflags);
 }
+#endif
 
 static bool do_load(DisasContext *dc, int rd, TCGv addr, MemOp mop,
                     int mem_index, bool rev)
@@ -760,12 +762,19 @@  static bool do_load(DisasContext *dc, int rd, TCGv addr, MemOp mop,
         }
     }
 
+    /*
+     * For system mode, enforce alignment if the cpu configuration
+     * requires it.  For user-mode, the Linux kernel will have fixed up
+     * any unaligned access, so emulate that by *not* setting MO_ALIGN.
+     */
+#ifndef CONFIG_USER_ONLY
     if (size > MO_8 &&
         (dc->tb_flags & MSR_EE) &&
         dc->cfg->unaligned_exceptions) {
         record_unaligned_ess(dc, rd, size, false);
         mop |= MO_ALIGN;
     }
+#endif
 
     tcg_gen_qemu_ld_i32(reg_for_write(dc, rd), addr, mem_index, mop);
 
@@ -906,12 +915,19 @@  static bool do_store(DisasContext *dc, int rd, TCGv addr, MemOp mop,
         }
     }
 
+    /*
+     * For system mode, enforce alignment if the cpu configuration
+     * requires it.  For user-mode, the Linux kernel will have fixed up
+     * any unaligned access, so emulate that by *not* setting MO_ALIGN.
+     */
+#ifndef CONFIG_USER_ONLY
     if (size > MO_8 &&
         (dc->tb_flags & MSR_EE) &&
         dc->cfg->unaligned_exceptions) {
         record_unaligned_ess(dc, rd, size, true);
         mop |= MO_ALIGN;
     }
+#endif
 
     tcg_gen_qemu_st_i32(reg_for_read(dc, rd), addr, mem_index, mop);