[PATCH 1/4] or1k: Fix Linux user space signal ABI

[Stafford Horne <shorne@gmail.com>]

The OpenRISC sigcontext structure has always been defined as:

    struct user_regs_struct {
	    /* GPR R0-R31... */
	    unsigned long gpr[32];
	    unsigned long pc;
	    unsigned long sr;
    };

    struct sigcontext {
	    struct user_regs_struct regs;  /* needs to be first */
	    unsigned long oldmask;	/* unused */
    };

With Linux v6.8 we added FPU support and repurposed the oldmask
to use for the FPCSR (floating point control status register).

    struct sigcontext {
	    struct user_regs_struct regs;  /* needs to be first */
	    union {
		    unsigned long fpcsr;
		    unsigned long oldmask;	/* unused */
	    };
    };

The definition of mcontext_t was always missing the extra space for
oldmask.  This patch adds the field __fpcsr to mcontext_t to fix the ABI
mismatch between glibc and Linux.
---
 sysdeps/unix/sysv/linux/or1k/sys/ucontext.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sysdeps/unix/sysv/linux/or1k/sys/ucontext.h b/sysdeps/unix/sysv/linux/or1k/sys/ucontext.h
index b17e919154..1b428592ee 100644
--- a/sysdeps/unix/sysv/linux/or1k/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/or1k/sys/ucontext.h
@@ -38,6 +38,7 @@ typedef struct
     unsigned long int __gprs[__NGREG];
     unsigned long int __pc;
     unsigned long int __sr;
+    unsigned long int __fpcsr;
   } mcontext_t;
 
 /* Userlevel context.  */
-- 
2.44.0