[PULL 35/37] linux-user: i386/signal: move fpstate at the end of the 32-bit frames

Paolo Bonzini posted 37 patches 3 years, 4 months ago
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <fam@euphon.net>, Laurent Vivier <laurent@vivier.eu>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Marcelo Tosatti <mtosatti@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Huacai Chen <chenhuacai@kernel.org>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Aurelien Jarno <aurelien@aurel32.net>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, "Cédric Le Goater" <clg@kaod.org>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Cornelia Huck <cohuck@redhat.com>, Thomas Huth <thuth@redhat.com>, David Hildenbrand <david@redhat.com>
[PULL 35/37] linux-user: i386/signal: move fpstate at the end of the 32-bit frames
Posted by Paolo Bonzini 3 years, 4 months ago
Recent versions of Linux moved the 32-bit fpstate towards the end of the
frame, so that the variable-sized xsave data does not overwrite the
(ABI-defined) extramask[] field.  Follow suit in QEMU.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 linux-user/i386/signal.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c
index 4372621a4d..76317a3d16 100644
--- a/linux-user/i386/signal.c
+++ b/linux-user/i386/signal.c
@@ -163,9 +163,16 @@ struct sigframe {
     abi_ulong pretcode;
     int sig;
     struct target_sigcontext sc;
-    struct target_fpstate fpstate;
+    /*
+     * The actual fpstate is placed after retcode[] below, to make
+     * room for the variable-sized xsave data.  The older unused fpstate
+     * has to be kept to avoid changing the offset of extramask[], which
+     * is part of the ABI.
+     */
+    struct target_fpstate fpstate_unused;
     abi_ulong extramask[TARGET_NSIG_WORDS-1];
     char retcode[8];
+    struct target_fpstate fpstate;
 };
 
 struct rt_sigframe {
@@ -175,8 +182,8 @@ struct rt_sigframe {
     abi_ulong puc;
     struct target_siginfo info;
     struct target_ucontext uc;
-    struct target_fpstate fpstate;
     char retcode[8];
+    struct target_fpstate fpstate;
 };
 
 #else
-- 
2.37.3