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8e6b0e2adf
[ Upstream commit e38eba3b77 ]
Flush all uncommitted user windows before calling the generic syscall
handlers for clone, fork, and vfork.
Prior to entering the arch common handlers sparc_{clone|fork|vfork}, the
arch-specific syscall wrappers for these syscalls will attempt to flush
all windows (including user windows).
In the window overflow trap handlers on both SPARC{32|64},
if the window can't be stored (i.e due to MMU related faults) the routine
backups the user window and increments a thread counter (wsaved).
By adding a synchronization point after the flush attempt, when fault
handling is enabled, any uncommitted user windows will be flushed.
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=31394
Closes: https://lore.kernel.org/sparclinux/fe5cc47167430007560501aabb28ba154985b661.camel@physik.fu-berlin.de/
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Ludwig Rydberg <ludwig.rydberg@gaisler.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20260119144753.27945-2-ludwig.rydberg@gaisler.com
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
121 lines
2.9 KiB
C
121 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* This file handles the architecture independent parts of process handling..
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*/
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#include <linux/compat.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/sched/task.h>
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#include <linux/sched/task_stack.h>
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#include <linux/signal.h>
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#include "kernel.h"
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asmlinkage long sparc_fork(struct pt_regs *regs)
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{
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unsigned long orig_i1;
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long ret;
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struct kernel_clone_args args = {
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.exit_signal = SIGCHLD,
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};
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synchronize_user_stack();
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orig_i1 = regs->u_regs[UREG_I1];
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/* Reuse the parent's stack for the child. */
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args.stack = regs->u_regs[UREG_FP];
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ret = kernel_clone(&args);
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/* If we get an error and potentially restart the system
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* call, we're screwed because copy_thread() clobbered
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* the parent's %o1. So detect that case and restore it
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* here.
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*/
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if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
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regs->u_regs[UREG_I1] = orig_i1;
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return ret;
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}
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asmlinkage long sparc_vfork(struct pt_regs *regs)
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{
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unsigned long orig_i1;
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long ret;
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struct kernel_clone_args args = {
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.flags = CLONE_VFORK | CLONE_VM,
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.exit_signal = SIGCHLD,
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};
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synchronize_user_stack();
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orig_i1 = regs->u_regs[UREG_I1];
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/* Reuse the parent's stack for the child. */
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args.stack = regs->u_regs[UREG_FP];
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ret = kernel_clone(&args);
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/* If we get an error and potentially restart the system
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* call, we're screwed because copy_thread() clobbered
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* the parent's %o1. So detect that case and restore it
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* here.
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*/
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if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
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regs->u_regs[UREG_I1] = orig_i1;
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return ret;
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}
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asmlinkage long sparc_clone(struct pt_regs *regs)
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{
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unsigned long orig_i1;
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unsigned int flags;
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long ret;
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struct kernel_clone_args args = {0};
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synchronize_user_stack();
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orig_i1 = regs->u_regs[UREG_I1];
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flags = lower_32_bits(regs->u_regs[UREG_I0]);
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args.flags = (flags & ~CSIGNAL);
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args.exit_signal = (flags & CSIGNAL);
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args.tls = regs->u_regs[UREG_I3];
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#ifdef CONFIG_COMPAT
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if (test_thread_flag(TIF_32BIT)) {
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args.pidfd = compat_ptr(regs->u_regs[UREG_I2]);
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args.child_tid = compat_ptr(regs->u_regs[UREG_I4]);
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args.parent_tid = compat_ptr(regs->u_regs[UREG_I2]);
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} else
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#endif
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{
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args.pidfd = (int __user *)regs->u_regs[UREG_I2];
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args.child_tid = (int __user *)regs->u_regs[UREG_I4];
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args.parent_tid = (int __user *)regs->u_regs[UREG_I2];
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}
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/* Did userspace give setup a separate stack for the child or are we
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* reusing the parent's?
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*/
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if (regs->u_regs[UREG_I1])
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args.stack = regs->u_regs[UREG_I1];
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else
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args.stack = regs->u_regs[UREG_FP];
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ret = kernel_clone(&args);
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/* If we get an error and potentially restart the system
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* call, we're screwed because copy_thread() clobbered
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* the parent's %o1. So detect that case and restore it
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* here.
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*/
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if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
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regs->u_regs[UREG_I1] = orig_i1;
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return ret;
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}
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