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sparc: share process creation helpers between sparc and sparc64

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As promised in the previous patch, this moves the process creation
helpers into a common process.c file that is shared between sparc and
sparc64. It allows us to get rid of quite a bit custom assembler and the
to remove the separe 32bit specific sparc_do_fork() call.

One thing to note, is that when clone() was called with a separate stack
for the child the assembler would align it. But copy_thread() has always
been doing that too so that line wasn't needed and can thus simply be
removed.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: linux-csky@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Link: https://lore.kernel.org/r/20200512171527.570109-3-christian.brauner@ubuntu.com
This commit is contained in:
Christian Brauner 2020-05-12 19:15:26 +02:00
parent dcad2a62bc
commit a4261d4bb4
No known key found for this signature in database
GPG key ID: 91C61BC06578DCA2
6 changed files with 123 additions and 149 deletions
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1
arch/sparc/kernel/Makefile
View file

@ -33,6 +33,7 @@ obj-y += irq_$(BITS).o
obj-$(CONFIG_SPARC32) += sun4m_irq.o sun4d_irq.o
obj-y += process_$(BITS).o
obj-y += process.o
obj-y += signal_$(BITS).o
obj-y += sigutil_$(BITS).o
obj-$(CONFIG_SPARC32) += ioport.o

29
arch/sparc/kernel/entry.S
View file

@ -869,14 +869,11 @@ flush_patch_two:
ld [%curptr + TI_TASK], %o4
rd %psr, %g4
WRITE_PAUSE
mov SIGCHLD, %o0 ! arg0: clone flags
rd %wim, %g5
WRITE_PAUSE
mov %fp, %o1 ! arg1: usp
std %g4, [%o4 + AOFF_task_thread + AOFF_thread_fork_kpsr]
add %sp, STACKFRAME_SZ, %o2 ! arg2: pt_regs ptr
mov 0, %o3
call sparc_do_fork
add %sp, STACKFRAME_SZ, %o0
call sparc_fork
mov %l5, %o7
/* Whee, kernel threads! */
@ -888,19 +885,11 @@ flush_patch_three:
ld [%curptr + TI_TASK], %o4
rd %psr, %g4
WRITE_PAUSE
/* arg0,1: flags,usp -- loaded already */
cmp %o1, 0x0 ! Is new_usp NULL?
rd %wim, %g5
WRITE_PAUSE
be,a 1f
mov %fp, %o1 ! yes, use callers usp
andn %o1, 7, %o1 ! no, align to 8 bytes
1:
std %g4, [%o4 + AOFF_task_thread + AOFF_thread_fork_kpsr]
add %sp, STACKFRAME_SZ, %o2 ! arg2: pt_regs ptr
mov 0, %o3
call sparc_do_fork
add %sp, STACKFRAME_SZ, %o0
call sparc_clone
mov %l5, %o7
/* Whee, real vfork! */
@ -914,13 +903,9 @@ flush_patch_four:
rd %wim, %g5
WRITE_PAUSE
std %g4, [%o4 + AOFF_task_thread + AOFF_thread_fork_kpsr]
sethi %hi(0x4000 | 0x0100 | SIGCHLD), %o0
mov %fp, %o1
or %o0, %lo(0x4000 | 0x0100 | SIGCHLD), %o0
sethi %hi(sparc_do_fork), %l1
mov 0, %o3
jmpl %l1 + %lo(sparc_do_fork), %g0
add %sp, STACKFRAME_SZ, %o2
sethi %hi(sparc_vfork), %l1
jmpl %l1 + %lo(sparc_vfork), %g0
add %sp, STACKFRAME_SZ, %o0
.align 4
linux_sparc_ni_syscall:

11
arch/sparc/kernel/kernel.h
View file

@ -14,6 +14,11 @@ extern const char *sparc_pmu_type;
extern unsigned int fsr_storage;
extern int ncpus_probed;
/* process{_32,_64}.c */
asmlinkage long sparc_clone(struct pt_regs *regs);
asmlinkage long sparc_fork(struct pt_regs *regs);
asmlinkage long sparc_vfork(struct pt_regs *regs);
#ifdef CONFIG_SPARC64
/* setup_64.c */
struct seq_file;
@ -153,12 +158,6 @@ void floppy_hardint(void);
extern unsigned long sun4m_cpu_startup;
extern unsigned long sun4d_cpu_startup;
/* process_32.c */
asmlinkage int sparc_do_fork(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size);
/* signal_32.c */
asmlinkage void do_sigreturn(struct pt_regs *regs);
asmlinkage void do_rt_sigreturn(struct pt_regs *regs);

110
arch/sparc/kernel/process.c Normal file
View file

@ -0,0 +1,110 @@
// SPDX-License-Identifier: GPL-2.0
/*
* This file handles the architecture independent parts of process handling..
*/
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/signal.h>
#include "kernel.h"
asmlinkage long sparc_fork(struct pt_regs *regs)
{
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
struct kernel_clone_args args = {
.exit_signal = SIGCHLD,
/* Reuse the parent's stack for the child. */
.stack = regs->u_regs[UREG_FP],
};
ret = _do_fork(&args);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread_tls() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
asmlinkage long sparc_vfork(struct pt_regs *regs)
{
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
struct kernel_clone_args args = {
.flags = CLONE_VFORK | CLONE_VM,
.exit_signal = SIGCHLD,
/* Reuse the parent's stack for the child. */
.stack = regs->u_regs[UREG_FP],
};
ret = _do_fork(&args);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread_tls() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
asmlinkage long sparc_clone(struct pt_regs *regs)
{
unsigned long orig_i1 = regs->u_regs[UREG_I1];
unsigned int flags = lower_32_bits(regs->u_regs[UREG_I0]);
long ret;
struct kernel_clone_args args = {
.flags = (flags & ~CSIGNAL),
.exit_signal = (flags & CSIGNAL),
.tls = regs->u_regs[UREG_I3],
};
#ifdef CONFIG_COMPAT
if (test_thread_flag(TIF_32BIT)) {
args.pidfd = compat_ptr(regs->u_regs[UREG_I2]);
args.child_tid = compat_ptr(regs->u_regs[UREG_I4]);
args.parent_tid = compat_ptr(regs->u_regs[UREG_I2]);
} else
#endif
{
args.pidfd = (int __user *)regs->u_regs[UREG_I2];
args.child_tid = (int __user *)regs->u_regs[UREG_I4];
args.parent_tid = (int __user *)regs->u_regs[UREG_I2];
}
/* Did userspace give setup a separate stack for the child or are we
* reusing the parent's?
*/
if (regs->u_regs[UREG_I1])
args.stack = regs->u_regs[UREG_I1];
else
args.stack = regs->u_regs[UREG_FP];
ret = _do_fork(&args);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread_tls() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}

27
arch/sparc/kernel/process_32.c
View file

@ -257,33 +257,6 @@ clone_stackframe(struct sparc_stackf __user *dst,
return sp;
}
asmlinkage int sparc_do_fork(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size)
{
unsigned long parent_tid_ptr, child_tid_ptr;
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
parent_tid_ptr = regs->u_regs[UREG_I2];
child_tid_ptr = regs->u_regs[UREG_I4];
ret = do_fork(clone_flags, stack_start, stack_size,
(int __user *) parent_tid_ptr,
(int __user *) child_tid_ptr);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
/* Copy a Sparc thread. The fork() return value conventions
* under SunOS are nothing short of bletcherous:
* Parent --> %o0 == childs pid, %o1 == 0

94
arch/sparc/kernel/process_64.c
View file

@ -572,100 +572,6 @@ barf:
force_sig(SIGSEGV);
}
asmlinkage long sparc_fork(struct pt_regs *regs)
{
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
struct kernel_clone_args args = {
.exit_signal = SIGCHLD,
/* Reuse the parent's stack for the child. */
.stack = regs->u_regs[UREG_FP],
};
ret = _do_fork(&args);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread_tls() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
asmlinkage long sparc_vfork(struct pt_regs *regs)
{
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
struct kernel_clone_args args = {
.flags = CLONE_VFORK | CLONE_VM,
.exit_signal = SIGCHLD,
/* Reuse the parent's stack for the child. */
.stack = regs->u_regs[UREG_FP],
};
ret = _do_fork(&args);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread_tls() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
asmlinkage long sparc_clone(struct pt_regs *regs)
{
unsigned long orig_i1 = regs->u_regs[UREG_I1];
unsigned int flags = lower_32_bits(regs->u_regs[UREG_I0]);
long ret;
struct kernel_clone_args args = {
.flags = (flags & ~CSIGNAL),
.exit_signal = (flags & CSIGNAL),
.tls = regs->u_regs[UREG_I3],
};
#ifdef CONFIG_COMPAT
if (test_thread_flag(TIF_32BIT)) {
args.pidfd = compat_ptr(regs->u_regs[UREG_I2]);
args.child_tid = compat_ptr(regs->u_regs[UREG_I4]);
args.parent_tid = compat_ptr(regs->u_regs[UREG_I2]);
} else
#endif
{
args.pidfd = (int __user *)regs->u_regs[UREG_I2];
args.child_tid = (int __user *)regs->u_regs[UREG_I4];
args.parent_tid = (int __user *)regs->u_regs[UREG_I2];
}
/* Did userspace setup a separate stack for the child or are we
* copying the parent's?
*/
if (regs->u_regs[UREG_I1])
args.stack = regs->u_regs[UREG_I1];
else
args.stack = regs->u_regs[UREG_FP];
ret = _do_fork(&args);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread_tls() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
/* Copy a Sparc thread. The fork() return value conventions
* under SunOS are nothing short of bletcherous:
* Parent --> %o0 == childs pid, %o1 == 0