aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT

Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set.

Not all architectures support the A.OUT binfmt, so the ELF binfmt should not
be permitted to go looking for A.OUT libraries to load in such a case.  Not
only that, but under such conditions A.OUT core dumps are not produced either.

To make this work, this patch also does the following:

 (1) Makes the existence of the contents of linux/a.out.h contingent on
     CONFIG_ARCH_SUPPORTS_AOUT.

 (2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT
     core dumping code.

 (3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline.  This
     is then included only where needed.  This means that this bit of arch
     code will be stored in the appropriate A.OUT binfmt module rather than
     the core kernel.

 (4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not
     needed) and FRV.

This patch depends on the previous patch to move STACK_TOP[_MAX] out of
asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT
format is available.

[jdike@addtoit.com: uml: re-remove accidentally restored code]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/kernel/process.c

@@ -317,68 +317,6 @@ copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 	return 0;
 }
 
-/*
- * Fill in the user structure for an ECOFF core dump.
- */
-void
-dump_thread(struct pt_regs * pt, struct user * dump)
-{
-	/* switch stack follows right below pt_regs: */
-	struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
-
-	dump->magic = CMAGIC;
-	dump->start_code  = current->mm->start_code;
-	dump->start_data  = current->mm->start_data;
-	dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
-	dump->u_tsize = ((current->mm->end_code - dump->start_code)
-			 >> PAGE_SHIFT);
-	dump->u_dsize = ((current->mm->brk + PAGE_SIZE-1 - dump->start_data)
-			 >> PAGE_SHIFT);
-	dump->u_ssize = (current->mm->start_stack - dump->start_stack
-			 + PAGE_SIZE-1) >> PAGE_SHIFT;
-
-	/*
-	 * We store the registers in an order/format that is
-	 * compatible with DEC Unix/OSF/1 as this makes life easier
-	 * for gdb.
-	 */
-	dump->regs[EF_V0]  = pt->r0;
-	dump->regs[EF_T0]  = pt->r1;
-	dump->regs[EF_T1]  = pt->r2;
-	dump->regs[EF_T2]  = pt->r3;
-	dump->regs[EF_T3]  = pt->r4;
-	dump->regs[EF_T4]  = pt->r5;
-	dump->regs[EF_T5]  = pt->r6;
-	dump->regs[EF_T6]  = pt->r7;
-	dump->regs[EF_T7]  = pt->r8;
-	dump->regs[EF_S0]  = sw->r9;
-	dump->regs[EF_S1]  = sw->r10;
-	dump->regs[EF_S2]  = sw->r11;
-	dump->regs[EF_S3]  = sw->r12;
-	dump->regs[EF_S4]  = sw->r13;
-	dump->regs[EF_S5]  = sw->r14;
-	dump->regs[EF_S6]  = sw->r15;
-	dump->regs[EF_A3]  = pt->r19;
-	dump->regs[EF_A4]  = pt->r20;
-	dump->regs[EF_A5]  = pt->r21;
-	dump->regs[EF_T8]  = pt->r22;
-	dump->regs[EF_T9]  = pt->r23;
-	dump->regs[EF_T10] = pt->r24;
-	dump->regs[EF_T11] = pt->r25;
-	dump->regs[EF_RA]  = pt->r26;
-	dump->regs[EF_T12] = pt->r27;
-	dump->regs[EF_AT]  = pt->r28;
-	dump->regs[EF_SP]  = rdusp();
-	dump->regs[EF_PS]  = pt->ps;
-	dump->regs[EF_PC]  = pt->pc;
-	dump->regs[EF_GP]  = pt->gp;
-	dump->regs[EF_A0]  = pt->r16;
-	dump->regs[EF_A1]  = pt->r17;
-	dump->regs[EF_A2]  = pt->r18;
-	memcpy((char *)dump->regs + EF_SIZE, sw->fp, 32 * 8);
-}
-EXPORT_SYMBOL(dump_thread);
-
 /*
  * Fill in the user structure for a ELF core dump.
  */

arch/arm/kernel/process.c

@@ -367,35 +367,6 @@ int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 }
 EXPORT_SYMBOL(dump_fpu);
 
-/*
- * fill in the user structure for a core dump..
- */
-void dump_thread(struct pt_regs * regs, struct user * dump)
-{
-	struct task_struct *tsk = current;
-
-	dump->magic = CMAGIC;
-	dump->start_code = tsk->mm->start_code;
-	dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
-
-	dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
-	dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	dump->u_ssize = 0;
-
-	dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
-	dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
-	dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
-	dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
-	dump->u_debugreg[4] = tsk->thread.debug.nsaved;
-
-	if (dump->start_stack < 0x04000000)
-		dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
-
-	dump->regs = *regs;
-	dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
-}
-EXPORT_SYMBOL(dump_thread);
-
 /*
  * Shuffle the argument into the correct register before calling the
  * thread function.  r1 is the thread argument, r2 is the pointer to

arch/m68k/kernel/process.c

@@ -315,53 +315,6 @@ int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 }
 EXPORT_SYMBOL(dump_fpu);
 
-/*
- * fill in the user structure for a core dump..
- */
-void dump_thread(struct pt_regs * regs, struct user * dump)
-{
-	struct switch_stack *sw;
-
-/* changed the size calculations - should hopefully work better. lbt */
-	dump->magic = CMAGIC;
-	dump->start_code = 0;
-	dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
-	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
-	dump->u_dsize = ((unsigned long) (current->mm->brk +
-					  (PAGE_SIZE-1))) >> PAGE_SHIFT;
-	dump->u_dsize -= dump->u_tsize;
-	dump->u_ssize = 0;
-
-	if (dump->start_stack < TASK_SIZE)
-		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
-
-	dump->u_ar0 = offsetof(struct user, regs);
-	sw = ((struct switch_stack *)regs) - 1;
-	dump->regs.d1 = regs->d1;
-	dump->regs.d2 = regs->d2;
-	dump->regs.d3 = regs->d3;
-	dump->regs.d4 = regs->d4;
-	dump->regs.d5 = regs->d5;
-	dump->regs.d6 = sw->d6;
-	dump->regs.d7 = sw->d7;
-	dump->regs.a0 = regs->a0;
-	dump->regs.a1 = regs->a1;
-	dump->regs.a2 = regs->a2;
-	dump->regs.a3 = sw->a3;
-	dump->regs.a4 = sw->a4;
-	dump->regs.a5 = sw->a5;
-	dump->regs.a6 = sw->a6;
-	dump->regs.d0 = regs->d0;
-	dump->regs.orig_d0 = regs->orig_d0;
-	dump->regs.stkadj = regs->stkadj;
-	dump->regs.sr = regs->sr;
-	dump->regs.pc = regs->pc;
-	dump->regs.fmtvec = (regs->format << 12) | regs->vector;
-	/* dump floating point stuff */
-	dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp);
-}
-EXPORT_SYMBOL(dump_thread);
-
 /*
  * sys_execve() executes a new program.
  */

arch/sparc/kernel/process.c

@@ -566,38 +566,6 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 	return 0;
 }
 
-/*
- * fill in the user structure for a core dump..
- */
-void dump_thread(struct pt_regs * regs, struct user * dump)
-{
-	unsigned long first_stack_page;
-
-	dump->magic = SUNOS_CORE_MAGIC;
-	dump->len = sizeof(struct user);
-	dump->regs.psr = regs->psr;
-	dump->regs.pc = regs->pc;
-	dump->regs.npc = regs->npc;
-	dump->regs.y = regs->y;
-	/* fuck me plenty */
-	memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
-	dump->uexec = current->thread.core_exec;
-	dump->u_tsize = (((unsigned long) current->mm->end_code) -
-		((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
-	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
-	dump->u_dsize -= dump->u_tsize;
-	dump->u_dsize &= ~(PAGE_SIZE - 1);
-	first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
-	dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
-	memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
-	dump->fpu.fpstatus.fsr = current->thread.fsr;
-	dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
-	dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
-	memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
-	       ((sizeof(unsigned long) * 2) * 16));
-	dump->sigcode = 0;
-}
-
 /*
  * fill in the fpu structure for a core dump.
  */

arch/sparc/kernel/sparc_ksyms.c

@@ -214,8 +214,6 @@ EXPORT_SYMBOL(kunmap_atomic);
 EXPORT_SYMBOL(svr4_setcontext);
 EXPORT_SYMBOL(svr4_getcontext);
 
-EXPORT_SYMBOL(dump_thread);
-
 /* prom symbols */
 EXPORT_SYMBOL(idprom);
 EXPORT_SYMBOL(prom_root_node);

arch/sparc64/kernel/binfmt_aout32.c

@@ -32,6 +32,7 @@
 #include <asm/uaccess.h>
 #include <asm/pgalloc.h>
 #include <asm/mmu_context.h>
+#include <asm/a.out-core.h>
 
 static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs);
 static int load_aout32_library(struct file*);
@@ -101,7 +102,7 @@ static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file,
 	current->flags |= PF_DUMPCORE;
        	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
 	dump.signal = signr;
-	dump_thread(regs, &dump);
+	aout_dump_thread(regs, &dump);
 
 /* If the size of the dump file exceeds the rlimit, then see what would happen
    if we wrote the stack, but not the data area.  */

arch/sparc64/kernel/process.c

@@ -725,17 +725,6 @@ pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 	return retval;
 }
 
-/*
- * fill in the user structure for a core dump..
- */
-void dump_thread(struct pt_regs * regs, struct user * dump)
-{
-	/* Only should be used for SunOS and ancient a.out
-	 * SparcLinux binaries...  Not worth implementing.
-	 */
-	memset(dump, 0, sizeof(struct user));
-}
-
 typedef struct {
 	union {
 		unsigned int	pr_regs[32];

arch/um/kernel/ksyms.c

@@ -60,7 +60,6 @@ EXPORT_SYMBOL(os_accept_connection);
 EXPORT_SYMBOL(os_rcv_fd);
 EXPORT_SYMBOL(run_helper);
 EXPORT_SYMBOL(start_thread);
-EXPORT_SYMBOL(dump_thread);
 
 #ifdef CONFIG_SMP
 

arch/um/kernel/process.c

@@ -258,10 +258,6 @@ void cpu_idle(void)
 	default_idle();
 }
 
-void dump_thread(struct pt_regs *regs, struct user *u)
-{
-}
-
 int __cant_sleep(void) {
 	return in_atomic() || irqs_disabled() || in_interrupt();
 	/* Is in_interrupt() really needed? */

arch/x86/kernel/process_32.c

@@ -539,55 +539,6 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 	return err;
 }
 
-/*
- * fill in the user structure for a core dump..
- */
-void dump_thread(struct pt_regs * regs, struct user * dump)
-{
-	u16 gs;
-
-/* changed the size calculations - should hopefully work better. lbt */
-	dump->magic = CMAGIC;
-	dump->start_code = 0;
-	dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
-	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
-	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
-	dump->u_dsize -= dump->u_tsize;
-	dump->u_ssize = 0;
-	dump->u_debugreg[0] = current->thread.debugreg0;
-	dump->u_debugreg[1] = current->thread.debugreg1;
-	dump->u_debugreg[2] = current->thread.debugreg2;
-	dump->u_debugreg[3] = current->thread.debugreg3;
-	dump->u_debugreg[4] = 0;
-	dump->u_debugreg[5] = 0;
-	dump->u_debugreg[6] = current->thread.debugreg6;
-	dump->u_debugreg[7] = current->thread.debugreg7;
-
-	if (dump->start_stack < TASK_SIZE)
-		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
-
-	dump->regs.bx = regs->bx;
-	dump->regs.cx = regs->cx;
-	dump->regs.dx = regs->dx;
-	dump->regs.si = regs->si;
-	dump->regs.di = regs->di;
-	dump->regs.bp = regs->bp;
-	dump->regs.ax = regs->ax;
-	dump->regs.ds = (u16)regs->ds;
-	dump->regs.es = (u16)regs->es;
-	dump->regs.fs = (u16)regs->fs;
-	savesegment(gs,gs);
-	dump->regs.orig_ax = regs->orig_ax;
-	dump->regs.ip = regs->ip;
-	dump->regs.cs = (u16)regs->cs;
-	dump->regs.flags = regs->flags;
-	dump->regs.sp = regs->sp;
-	dump->regs.ss = (u16)regs->ss;
-
-	dump->u_fpvalid = dump_fpu (regs, &dump->i387);
-}
-EXPORT_SYMBOL(dump_thread);
-
 #ifdef CONFIG_SECCOMP
 static void hard_disable_TSC(void)
 {

fs/Kconfig.binfmt

@@ -61,7 +61,8 @@ config BINFMT_SHARED_FLAT
 
 config BINFMT_AOUT
 	tristate "Kernel support for a.out and ECOFF binaries"
-	depends on X86_32 || ALPHA || ARM || M68K || SPARC32
+	depends on ARCH_SUPPORTS_AOUT && \
+		(X86_32 || ALPHA || ARM || M68K || SPARC32)
 	---help---
 	  A.out (Assembler.OUTput) is a set of formats for libraries and
 	  executables used in the earliest versions of UNIX.  Linux used

fs/binfmt_aout.c

@@ -28,6 +28,7 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
+#include <asm/a.out-core.h>
 
 static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
 static int load_aout_library(struct file*);
@@ -118,7 +119,7 @@ static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, u
 	dump.u_ar0 = offsetof(struct user, regs);
 #endif
 	dump.signal = signr;
-	dump_thread(regs, &dump);
+	aout_dump_thread(regs, &dump);
 
 /* If the size of the dump file exceeds the rlimit, then see what would happen
    if we wrote the stack, but not the data area.  */