[Stable-8.2.1 61/71] linux-user/riscv: Adjust vdso signal frame cfa offsets

[Michael Tokarev]

From: Richard Henderson <richard.henderson@linaro.org>

A typo in sizeof_reg put the registers at the wrong offset.

Simplify the expressions to use positive addresses from the
start of uc_mcontext instead of negative addresses from the
end of uc_mcontext.

Reported-by: Vineet Gupta <vineetg@rivosinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
(cherry picked from commit 1b21fe27e75a59bfe2513f5abcc6a18cfc35cfc8)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/linux-user/riscv/vdso-32.so b/linux-user/riscv/vdso-32.so
index 1ad1e5cbbb..c2ce2a4757 100755
Binary files a/linux-user/riscv/vdso-32.so and b/linux-user/riscv/vdso-32.so 
differ
diff --git a/linux-user/riscv/vdso-64.so b/linux-user/riscv/vdso-64.so
index 83992bebe6..ae49f5b043 100755
Binary files a/linux-user/riscv/vdso-64.so and b/linux-user/riscv/vdso-64.so 
differ
diff --git a/linux-user/riscv/vdso.S b/linux-user/riscv/vdso.S
index a86d8fc488..c37275233a 100644
--- a/linux-user/riscv/vdso.S
+++ b/linux-user/riscv/vdso.S
@@ -101,12 +101,12 @@ endf __vdso_flush_icache
        .cfi_startproc simple
        .cfi_signal_frame
 
-#define sizeof_reg     (__riscv_xlen / 4)
+#define sizeof_reg     (__riscv_xlen / 8)
 #define sizeof_freg    8
-#define B_GR   (offsetof_uc_mcontext - sizeof_rt_sigframe)
-#define B_FR   (offsetof_uc_mcontext - sizeof_rt_sigframe + offsetof_freg0)
+#define B_GR   0
+#define B_FR   offsetof_freg0
 
-       .cfi_def_cfa    2, sizeof_rt_sigframe
+       .cfi_def_cfa    2, offsetof_uc_mcontext
 
        /* Return address */
        .cfi_return_column 64
-- 
2.39.2