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Subject[PATCH 2/3] sparc: share process creation helpers between sparc and sparc64
Date
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.

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
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
arch/sparc/kernel/Makefile | 1 +
arch/sparc/kernel/entry.S | 29 +++------
arch/sparc/kernel/kernel.h | 7 +--
arch/sparc/kernel/process.c | 111 +++++++++++++++++++++++++++++++++
arch/sparc/kernel/process_32.c | 27 --------
arch/sparc/kernel/process_64.c | 97 ----------------------------
6 files changed, 122 insertions(+), 150 deletions(-)
create mode 100644 arch/sparc/kernel/process.c

diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile
index 97c0e19263d1..d3a0e072ebe8 100644
--- a/arch/sparc/kernel/Makefile
+++ b/arch/sparc/kernel/Makefile
@@ -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
diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S
index 4d3696973325..7925e8e5092b 100644
--- a/arch/sparc/kernel/entry.S
+++ b/arch/sparc/kernel/entry.S
@@ -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:
diff --git a/arch/sparc/kernel/kernel.h b/arch/sparc/kernel/kernel.h
index f6f498ba3198..3529e16ece20 100644
--- a/arch/sparc/kernel/kernel.h
+++ b/arch/sparc/kernel/kernel.h
@@ -154,10 +154,9 @@ 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);
+asmlinkage int sparc_clone(struct pt_regs *regs);
+asmlinkage int sparc_fork(struct pt_regs *regs);
+asmlinkage int sparc_vfork(struct pt_regs *regs);

/* signal_32.c */
asmlinkage void do_sigreturn(struct pt_regs *regs);
diff --git a/arch/sparc/kernel/process.c b/arch/sparc/kernel/process.c
new file mode 100644
index 000000000000..9d81edafbad5
--- /dev/null
+++ b/arch/sparc/kernel/process.c
@@ -0,0 +1,111 @@
+// 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>
+
+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];
+
+ if (!legacy_clone_args_valid(&args))
+ return -EINVAL;
+
+ 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;
+}
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 26cca65e9246..9c510e6625aa 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -258,33 +258,6 @@ 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
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index 0222f638bdb2..309e17f3d01c 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -573,103 +573,6 @@ void fault_in_user_windows(struct pt_regs *regs)
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];
-
- if (!legacy_clone_args_valid(&args))
- return -EINVAL;
-
- 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
--
2.26.2
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