elf_prstatus: collect the common part (everything before pr_reg) into a struct

Preparations to doing i386 compat elf_prstatus sanely - rather than duplicating
the beginning of compat_elf_prstatus, take these fields into a separate
structure (compat_elf_prstatus_common), so that it could be reused.  Due to
the incestous relationship between binfmt_elf.c and compat_binfmt_elf.c we
need the same shape change done to native struct elf_prstatus, gathering the
fields prior to pr_reg into a new structure (struct elf_prstatus_common).

Fortunately, offset of pr_reg is always a multiple of 16 with no padding
right before it, so it's possible to turn all the stuff prior to it into
a single member without disturbing the layout.

[build fix from Geert Uytterhoeven folded in]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 16 insertions, 7 deletions

diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index fec70d662d0c..4f47741005d2 100644
--- a/arch/ia64/kernel/crash.c
+++ b/arch/ia64/kernel/crash.c
@@ -43,7 +43,7 @@ crash_save_this_cpu(void)
 
 	elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg);
 	memset(prstatus, 0, sizeof(*prstatus));
-	prstatus->pr_pid = current->pid;
+	prstatus->common.pr_pid = current->pid;
 
 	ia64_dump_cpu_regs(dst);
 	cfm = dst[43];
diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 6ee3f7218c67..136dc0c9300d 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -44,7 +44,8 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #include <linux/math64.h>
 
 #define elf_prstatus elf_prstatus32
-struct elf_prstatus32
+#define elf_prstatus_common elf_prstatus32_common
+struct elf_prstatus32_common
 {
 	struct elf_siginfo pr_info;	/* Info associated with signal */
 	short	pr_cursig;		/* Current signal */
@@ -58,6 +59,10 @@ struct elf_prstatus32
 	struct old_timeval32 pr_stime; /* System time */
 	struct old_timeval32 pr_cutime;/* Cumulative user time */
 	struct old_timeval32 pr_cstime;/* Cumulative system time */
+};
+struct elf_prstatus32
+{
+	struct elf_prstatus32_common common:
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index 6dd103d3cebb..b1f4b8f1dee7 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -49,7 +49,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #include <linux/math64.h>
 
 #define elf_prstatus elf_prstatus32
-struct elf_prstatus32
+struct elf_prstatus32_common
 {
 	struct elf_siginfo pr_info;	/* Info associated with signal */
 	short	pr_cursig;		/* Current signal */
@@ -63,6 +63,10 @@ struct elf_prstatus32
 	struct old_timeval32 pr_stime; /* System time */
 	struct old_timeval32 pr_cutime;/* Cumulative user time */
 	struct old_timeval32 pr_cstime;/* Cumulative system time */
+};
+struct elf_prstatus32
+{
+	struct elf_prstatus32_common common:
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };
diff --git a/arch/powerpc/platforms/powernv/opal-core.c b/arch/powerpc/platforms/powernv/opal-core.c
index 23571f0b555a..0d9ba70f7251 100644
--- a/arch/powerpc/platforms/powernv/opal-core.c
+++ b/arch/powerpc/platforms/powernv/opal-core.c
@@ -119,8 +119,8 @@ static void fill_prstatus(struct elf_prstatus *prstatus, int pir,
 	 * As a PIR value could also be '0', add an offset of '100'
 	 * to every PIR to avoid misinterpretations in GDB.
 	 */
-	prstatus->pr_pid  = cpu_to_be32(100 + pir);
-	prstatus->pr_ppid = cpu_to_be32(1);
+	prstatus->common.pr_pid  = cpu_to_be32(100 + pir);
+	prstatus->common.pr_ppid = cpu_to_be32(1);
 
 	/*
 	 * Indicate SIGUSR1 for crash initiated from kernel.
@@ -130,7 +130,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus, int pir,
 		short sig;
 
 		sig = kernel_initiated ? SIGUSR1 : SIGTERM;
-		prstatus->pr_cursig = cpu_to_be16(sig);
+		prstatus->common.pr_cursig = cpu_to_be16(sig);
 	}
 }
 
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 205b2e2648aa..0e36dfc9ccd6 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -365,7 +365,7 @@ static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
 	memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
 	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
 	memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
-	nt_prstatus.pr_pid = cpu;
+	nt_prstatus.common.pr_pid = cpu;
 	/* Prepare fpregset (floating point) note */
 	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
 	memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));