[PULL 74/75] linux-user/microblaze: Fix little-endianness binary

Philippe Mathieu-Daudé posted 75 patches 4 weeks, 1 day ago
Maintainers: Laurent Vivier <laurent@vivier.eu>, Richard Henderson <richard.henderson@linaro.org>, Peter Maydell <peter.maydell@linaro.org>, Michael Rolnik <mrolnik@gmail.com>, Brian Cain <brian.cain@oss.qualcomm.com>, Helge Deller <deller@gmx.de>, Song Gao <gaosong@loongson.cn>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Aurelien Jarno <aurelien@aurel32.net>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <arikalo@gmail.com>, Stafford Horne <shorne@gmail.com>, Nicholas Piggin <npiggin@gmail.com>, Chinmay Rath <rathc@linux.ibm.com>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Weiwei Li <liwei1518@gmail.com>, Daniel Henrique Barboza <dbarboza@ventanamicro.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>, Yoshinori Sato <yoshinori.sato@nifty.com>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Artyom Tarasenko <atar4qemu@gmail.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Max Filippov <jcmvbkbc@gmail.com>
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[PULL 74/75] linux-user/microblaze: Fix little-endianness binary
Posted by Philippe Mathieu-Daudé 4 weeks, 1 day ago
MicroBlaze CPU model has a "little-endian" property, pointing to
the @endi internal field. Commit c36ec3a9655 ("hw/microblaze:
Explicit CPU endianness") took care of having all MicroBlaze
boards with an explicit default endianness, so later commit
415aae543ed ("target/microblaze: Consider endianness while
translating code") could infer the endianness at runtime from
the @endi field, and not a compile time via the TARGET_BIG_ENDIAN
definition. Doing so, we forgot to make the endianness explicit
on user emulation, so there all CPUs are started with the default
"little-endian=off" value, leading to breaking support for little
endian binaries:

  $ readelf -h ./hello-world-mbel
  ELF Header:
    Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
    Class:                             ELF32
    Data:                              2's complement, little endian

  $ qemu-microblazeel ./hello-world-mbel
  qemu: uncaught target signal 11 (Segmentation fault) - core dumped
  Segmentation fault (core dumped)

Fix by restoring the previous behavior of starting with the
builtin endianness of the binary:

  $ qemu-microblazeel ./hello-world-mbel
  Hello World

Cc: qemu-stable@nongnu.org
Fixes: 415aae543ed ("target/microblaze: Consider endianness while translating code")
Reported-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Message-Id: <20251006173350.17455-1-philmd@linaro.org>
---
 linux-user/microblaze/elfload.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/linux-user/microblaze/elfload.c b/linux-user/microblaze/elfload.c
index 7eb1b26d170..bdc0a953d59 100644
--- a/linux-user/microblaze/elfload.c
+++ b/linux-user/microblaze/elfload.c
@@ -8,7 +8,8 @@
 
 const char *get_elf_cpu_model(uint32_t eflags)
 {
-    return "any";
+    return TARGET_BIG_ENDIAN ? "any,little-endian=off"
+                             : "any,little-endian=on";
 }
 
 void elf_core_copy_regs(target_elf_gregset_t *r, const CPUMBState *env)
-- 
2.51.0