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fork-v5.9

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Merge tag 'fork-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull fork cleanups from Christian Brauner:
 "This is cleanup series from when we reworked a chunk of the process
  creation paths in the kernel and switched to struct
  {kernel_}clone_args.

  High-level this does two main things:

   - Remove the double export of both do_fork() and _do_fork() where
     do_fork() used the incosistent legacy clone calling convention.

     Now we only export _do_fork() which is based on struct
     kernel_clone_args.

   - Remove the copy_thread_tls()/copy_thread() split making the
     architecture specific HAVE_COYP_THREAD_TLS config option obsolete.

  This switches all remaining architectures to select
  HAVE_COPY_THREAD_TLS and thus to the copy_thread_tls() calling
  convention. The current split makes the process creation codepaths
  more convoluted than they need to be. Each architecture has their own
  copy_thread() function unless it selects HAVE_COPY_THREAD_TLS then it
  has a copy_thread_tls() function.

  The split is not needed anymore nowadays, all architectures support
  CLONE_SETTLS but quite a few of them never bothered to select
  HAVE_COPY_THREAD_TLS and instead simply continued to use copy_thread()
  and use the old calling convention. Removing this split cleans up the
  process creation codepaths and paves the way for implementing clone3()
  on such architectures since it requires the copy_thread_tls() calling
  convention.

  After having made each architectures support copy_thread_tls() this
  series simply renames that function back to copy_thread(). It also
  switches all architectures that call do_fork() directly over to
  _do_fork() and the struct kernel_clone_args calling convention. This
  is a corollary of switching the architectures that did not yet support
  it over to copy_thread_tls() since do_fork() is conditional on not
  supporting copy_thread_tls() (Mostly because it lacks a separate
  argument for tls which is trivial to fix but there's no need for this
  function to exist.).

  The do_fork() removal is in itself already useful as it allows to to
  remove the export of both do_fork() and _do_fork() we currently have
  in favor of only _do_fork(). This has already been discussed back when
  we added clone3(). The legacy clone() calling convention is - as is
  probably well-known - somewhat odd:

    #
    # ABI hall of shame
    #
    config CLONE_BACKWARDS
    config CLONE_BACKWARDS2
    config CLONE_BACKWARDS3

  that is aggravated by the fact that some architectures such as sparc
  follow the CLONE_BACKWARDSx calling convention but don't really select
  the corresponding config option since they call do_fork() directly.

  So do_fork() enforces a somewhat arbitrary calling convention in the
  first place that doesn't really help the individual architectures that
  deviate from it. They can thus simply be switched to _do_fork()
  enforcing a single calling convention. (I really hope that any new
  architectures will __not__ try to implement their own calling
  conventions...)

  Most architectures already have made a similar switch (m68k comes to
  mind).

  Overall this removes more code than it adds even with a good portion
  of added comments. It simplifies a chunk of arch specific assembly
  either by moving the code into C or by simply rewriting the assembly.

  Architectures that have been touched in non-trivial ways have all been
  actually boot and stress tested: sparc and ia64 have been tested with
  Debian 9 images. They are the two architectures which have been
  touched the most. All non-trivial changes to architectures have seen
  acks from the relevant maintainers. nios2 with a custom built
  buildroot image. h8300 I couldn't get something bootable to test on
  but the changes have been fairly automatic and I'm sure we'll hear
  people yell if I broke something there.

  All other architectures that have been touched in trivial ways have
  been compile tested for each single patch of the series via git rebase
  -x "make ..." v5.8-rc2. arm{64} and x86{_64} have been boot tested
  even though they have just been trivially touched (removal of the
  HAVE_COPY_THREAD_TLS macro from their Kconfig) because well they are
  basically "core architectures" and since it is trivial to get your
  hands on a useable image"

* tag 'fork-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  arch: rename copy_thread_tls() back to copy_thread()
  arch: remove HAVE_COPY_THREAD_TLS
  unicore: switch to copy_thread_tls()
  sh: switch to copy_thread_tls()
  nds32: switch to copy_thread_tls()
  microblaze: switch to copy_thread_tls()
  hexagon: switch to copy_thread_tls()
  c6x: switch to copy_thread_tls()
  alpha: switch to copy_thread_tls()
  fork: remove do_fork()
  h8300: select HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
  nios2: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
  ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args
  sparc: unconditionally enable HAVE_COPY_THREAD_TLS
  sparc: share process creation helpers between sparc and sparc64
  sparc64: enable HAVE_COPY_THREAD_TLS
  fork: fold legacy_clone_args_valid() into _do_fork()
This commit is contained in:
Linus Torvalds 2020-08-04 14:47:45 -07:00
commit 9ba27414f2
52 changed files with 274 additions and 286 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/Kconfig
View File

@ -754,13 +754,6 @@ config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
depends on MMU
select ARCH_HAS_ELF_RANDOMIZE
config HAVE_COPY_THREAD_TLS
bool
help
Architecture provides copy_thread_tls to accept tls argument via
normal C parameter passing, rather than extracting the syscall
argument from pt_regs.
config HAVE_STACK_VALIDATION
bool
help

9
arch/alpha/kernel/process.c
View File

@ -233,10 +233,9 @@ release_thread(struct task_struct *dead_task)
/*
* Copy architecture-specific thread state
*/
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg,
struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p,
unsigned long tls)
{
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
@ -267,7 +266,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
required for proper operation in the case of a threaded
application calling fork. */
if (clone_flags & CLONE_SETTLS)
childti->pcb.unique = regs->r20;
childti->pcb.unique = tls;
else
regs->r20 = 0; /* OSF/1 has some strange fork() semantics. */
childti->pcb.usp = usp ?: rdusp();

1
arch/arc/Kconfig
View File

@ -29,7 +29,6 @@ config ARC
select GENERIC_SMP_IDLE_THREAD
select HAVE_ARCH_KGDB
select HAVE_ARCH_TRACEHOOK
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_DEBUG_KMEMLEAK
select HAVE_FUTEX_CMPXCHG if FUTEX

5
arch/arc/kernel/process.c
View File

@ -173,8 +173,9 @@ asmlinkage void ret_from_fork(void);
* | user_r25 |
* ------------------ <===== END of PAGE
*/
int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p,
unsigned long tls)
{
struct pt_regs *c_regs; /* child's pt_regs */
unsigned long *childksp; /* to unwind out of __switch_to() */

1
arch/arm/Kconfig
View File

@ -72,7 +72,6 @@ config ARM
select HAVE_ARM_SMCCC if CPU_V7
select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
select HAVE_CONTEXT_TRACKING
select HAVE_COPY_THREAD_TLS
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
select HAVE_DMA_CONTIGUOUS if MMU

5
arch/arm/kernel/process.c
View File

@ -225,9 +225,8 @@ void release_thread(struct task_struct *dead_task)
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
int
copy_thread_tls(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p, unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p, unsigned long tls)
{
struct thread_info *thread = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);

1
arch/arm64/Kconfig
View File

@ -149,7 +149,6 @@ config ARM64
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_CONTEXT_TRACKING
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS

2
arch/arm64/kernel/process.c
View File

@ -375,7 +375,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
asmlinkage void ret_from_fork(void) asm("ret_from_fork");
int copy_thread_tls(unsigned long clone_flags, unsigned long stack_start,
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);

4
arch/c6x/kernel/process.c
View File

@ -105,8 +105,8 @@ void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp)
* Copy a new thread context in its stack.
*/
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long ustk_size,
struct task_struct *p)
unsigned long ustk_size, struct task_struct *p,
unsigned long tls)
{
struct pt_regs *childregs;

1
arch/csky/Kconfig
View File

@ -38,7 +38,6 @@ config CSKY
select GX6605S_TIMER if CPU_CK610
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_AUDITSYSCALL
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS

2
arch/csky/kernel/process.c
View File

@ -40,7 +40,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
return sw->r15;
}
int copy_thread_tls(unsigned long clone_flags,
int copy_thread(unsigned long clone_flags,
unsigned long usp,
unsigned long kthread_arg,
struct task_struct *p,

17
arch/h8300/kernel/process.c
View File

@ -105,9 +105,8 @@ void flush_thread(void)
{
}
int copy_thread(unsigned long clone_flags,
unsigned long usp, unsigned long topstk,
struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long topstk, struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs;
@ -159,11 +158,19 @@ asmlinkage int sys_clone(unsigned long __user *args)
unsigned long newsp;
uintptr_t parent_tidptr;
uintptr_t child_tidptr;
struct kernel_clone_args kargs = {};
get_user(clone_flags, &args[0]);
get_user(newsp, &args[1]);
get_user(parent_tidptr, &args[2]);
get_user(child_tidptr, &args[3]);
return do_fork(clone_flags, newsp, 0,
(int __user *)parent_tidptr, (int __user *)child_tidptr);
kargs.flags = (lower_32_bits(clone_flags) & ~CSIGNAL);
kargs.pidfd = (int __user *)parent_tidptr;
kargs.child_tid = (int __user *)child_tidptr;
kargs.parent_tid = (int __user *)parent_tidptr;
kargs.exit_signal = (lower_32_bits(clone_flags) & CSIGNAL);
kargs.stack = newsp;
return _do_fork(&kargs);
}

6
arch/hexagon/kernel/process.c
View File

@ -50,8 +50,8 @@ void arch_cpu_idle(void)
/*
* Copy architecture-specific thread state
*/
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct thread_info *ti = task_thread_info(p);
struct hexagon_switch_stack *ss;
@ -100,7 +100,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
* ugp is used to provide TLS support.
*/
if (clone_flags & CLONE_SETTLS)
childregs->ugp = childregs->r04;
childregs->ugp = tls;
/*
* Parent sees new pid -- not necessary, not even possible at

32
arch/ia64/kernel/entry.S
View File

@ -112,19 +112,16 @@ GLOBAL_ENTRY(sys_clone2)
.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
alloc r16=ar.pfs,8,2,6,0
DO_SAVE_SWITCH_STACK
adds r2=PT(R16)+IA64_SWITCH_STACK_SIZE+16,sp
mov loc0=rp
mov loc1=r16 // save ar.pfs across do_fork
mov loc1=r16 // save ar.pfs across ia64_clone
.body
mov out0=in0
mov out1=in1
mov out2=in2
tbit.nz p6,p0=in0,CLONE_SETTLS_BIT
mov out3=in3 // parent_tidptr: valid only w/CLONE_PARENT_SETTID
;;
(p6) st8 [r2]=in5 // store TLS in r16 for copy_thread()
mov out4=in4 // child_tidptr: valid only w/CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID
mov out0=in0 // out0 = clone_flags
br.call.sptk.many rp=do_fork
mov out3=in3
mov out4=in4
mov out5=in5
br.call.sptk.many rp=ia64_clone
.ret1: .restore sp
adds sp=IA64_SWITCH_STACK_SIZE,sp // pop the switch stack
mov ar.pfs=loc1
@ -143,19 +140,16 @@ GLOBAL_ENTRY(sys_clone)
.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
alloc r16=ar.pfs,8,2,6,0
DO_SAVE_SWITCH_STACK
adds r2=PT(R16)+IA64_SWITCH_STACK_SIZE+16,sp
mov loc0=rp
mov loc1=r16 // save ar.pfs across do_fork
mov loc1=r16 // save ar.pfs across ia64_clone
.body
mov out0=in0
mov out1=in1
mov out2=16 // stacksize (compensates for 16-byte scratch area)
tbit.nz p6,p0=in0,CLONE_SETTLS_BIT
mov out3=in2 // parent_tidptr: valid only w/CLONE_PARENT_SETTID
;;
(p6) st8 [r2]=in4 // store TLS in r13 (tp)
mov out4=in3 // child_tidptr: valid only w/CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID
mov out0=in0 // out0 = clone_flags
br.call.sptk.many rp=do_fork
mov out3=in3
mov out4=in4
mov out5=in5
br.call.sptk.many rp=ia64_clone
.ret2: .restore sp
adds sp=IA64_SWITCH_STACK_SIZE,sp // pop the switch stack
mov ar.pfs=loc1
@ -590,7 +584,7 @@ GLOBAL_ENTRY(ia64_ret_from_clone)
nop.i 0
/*
* We need to call schedule_tail() to complete the scheduling process.
* Called by ia64_switch_to() after do_fork()->copy_thread(). r8 contains the
* Called by ia64_switch_to() after ia64_clone()->copy_thread(). r8 contains the
* address of the previously executing task.
*/
br.call.sptk.many rp=ia64_invoke_schedule_tail

29
arch/ia64/kernel/process.c
View File

@ -296,7 +296,7 @@ ia64_load_extra (struct task_struct *task)
pfm_load_regs(task);
info = __this_cpu_read(pfm_syst_info);
if (info & PFM_CPUINFO_SYST_WIDE)
if (info & PFM_CPUINFO_SYST_WIDE)
pfm_syst_wide_update_task(task, info, 1);
#endif
}
@ -310,7 +310,7 @@ ia64_load_extra (struct task_struct *task)
*
* <clone syscall> <some kernel call frames>
* sys_clone :
* do_fork do_fork
* _do_fork _do_fork
* copy_thread copy_thread
*
* This means that the stack layout is as follows:
@ -333,9 +333,8 @@ ia64_load_extra (struct task_struct *task)
* so there is nothing to worry about.
*/
int
copy_thread(unsigned long clone_flags,
unsigned long user_stack_base, unsigned long user_stack_size,
struct task_struct *p)
copy_thread(unsigned long clone_flags, unsigned long user_stack_base,
unsigned long user_stack_size, struct task_struct *p, unsigned long tls)
{
extern char ia64_ret_from_clone;
struct switch_stack *child_stack, *stack;
@ -416,7 +415,7 @@ copy_thread(unsigned long clone_flags,
rbs_size = stack->ar_bspstore - rbs;
memcpy((void *) child_rbs, (void *) rbs, rbs_size);
if (clone_flags & CLONE_SETTLS)
child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
child_ptregs->r13 = tls;
if (user_stack_base) {
child_ptregs->r12 = user_stack_base + user_stack_size - 16;
child_ptregs->ar_bspstore = user_stack_base;
@ -441,6 +440,24 @@ copy_thread(unsigned long clone_flags,
return retval;
}
asmlinkage long ia64_clone(unsigned long clone_flags, unsigned long stack_start,
unsigned long stack_size, unsigned long parent_tidptr,
unsigned long child_tidptr, unsigned long tls)
{
struct kernel_clone_args args = {
.flags = (lower_32_bits(clone_flags) & ~CSIGNAL),
.pidfd = (int __user *)parent_tidptr,
.child_tid = (int __user *)child_tidptr,
.parent_tid = (int __user *)parent_tidptr,
.exit_signal = (lower_32_bits(clone_flags) & CSIGNAL),
.stack = stack_start,
.stack_size = stack_size,
.tls = tls,
};
return _do_fork(&args);
}
static void
do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
{

1
arch/m68k/Kconfig
View File

@ -14,7 +14,6 @@ config M68K
select HAVE_AOUT if MMU
select HAVE_ASM_MODVERSIONS
select HAVE_DEBUG_BUGVERBOSE
select HAVE_COPY_THREAD_TLS
select GENERIC_IRQ_SHOW
select GENERIC_ATOMIC64
select HAVE_UID16

8
arch/m68k/kernel/process.c
View File

@ -125,9 +125,6 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
.tls = regs->d5,
};
if (!legacy_clone_args_valid(&args))
return -EINVAL;
return _do_fork(&args);
}
@ -141,9 +138,8 @@ asmlinkage int m68k_clone3(struct pt_regs *regs)
return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
}
int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p,
unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct fork_frame {
struct switch_stack sw;

6
arch/microblaze/kernel/process.c
View File

@ -54,8 +54,8 @@ void flush_thread(void)
{
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);
struct thread_info *ti = task_thread_info(p);
@ -114,7 +114,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
* which contains TLS area
*/
if (clone_flags & CLONE_SETTLS)
childregs->r21 = childregs->r10;
childregs->r21 = tls;
return 0;
}

1
arch/mips/Kconfig
View File

@ -51,7 +51,6 @@ config MIPS
select HAVE_CBPF_JIT if !64BIT && !CPU_MICROMIPS
select HAVE_CONTEXT_TRACKING
select HAVE_TIF_NOHZ
select HAVE_COPY_THREAD_TLS
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DEBUG_STACKOVERFLOW

5
arch/mips/kernel/process.c
View File

@ -119,8 +119,9 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
/*
* Copy architecture-specific thread state
*/
int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p,
unsigned long tls)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs, *regs = current_pt_regs();

4
arch/nds32/kernel/process.c
View File

@ -150,7 +150,7 @@ DEFINE_PER_CPU(struct task_struct *, __entry_task);
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p)
unsigned long stk_sz, struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);
@ -170,7 +170,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
childregs->uregs[0] = 0;
childregs->osp = 0;
if (clone_flags & CLONE_SETTLS)
childregs->uregs[25] = childregs->uregs[3];
childregs->uregs[25] = tls;
}
/* cpu context switching */
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;

7
arch/nios2/kernel/entry.S
View File

@ -389,12 +389,7 @@ ENTRY(ret_from_interrupt)
*/
ENTRY(sys_clone)
SAVE_SWITCH_STACK
addi sp, sp, -4
stw r7, 0(sp) /* Pass 5th arg thru stack */
mov r7, r6 /* 4th arg is 3rd of clone() */
mov r6, zero /* 3rd arg always 0 */
call do_fork
addi sp, sp, 4
call nios2_clone
RESTORE_SWITCH_STACK
ret

23
arch/nios2/kernel/process.c
View File

@ -100,8 +100,8 @@ void flush_thread(void)
{
}
int copy_thread(unsigned long clone_flags,
unsigned long usp, unsigned long arg, struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);
struct pt_regs *regs;
@ -140,7 +140,7 @@ int copy_thread(unsigned long clone_flags,
/* Initialize tls register. */
if (clone_flags & CLONE_SETTLS)
childstack->r23 = regs->r8;
childstack->r23 = tls;
return 0;
}
@ -259,3 +259,20 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
{
return 0; /* Nios2 has no FPU and thus no FPU registers */
}
asmlinkage int nios2_clone(unsigned long clone_flags, unsigned long newsp,
int __user *parent_tidptr, int __user *child_tidptr,
unsigned long tls)
{
struct kernel_clone_args args = {
.flags = (lower_32_bits(clone_flags) & ~CSIGNAL),
.pidfd = parent_tidptr,
.child_tid = child_tidptr,
.parent_tid = parent_tidptr,
.exit_signal = (lower_32_bits(clone_flags) & CSIGNAL),
.stack = newsp,
.tls = tls,
};
return _do_fork(&args);
}

1
arch/openrisc/Kconfig
View File

@ -16,7 +16,6 @@ config OPENRISC
select HANDLE_DOMAIN_IRQ
select GPIOLIB
select HAVE_ARCH_TRACEHOOK
select HAVE_COPY_THREAD_TLS
select SPARSE_IRQ
select GENERIC_IRQ_CHIP
select GENERIC_IRQ_PROBE

6
arch/openrisc/kernel/process.c
View File

@ -116,7 +116,7 @@ void release_thread(struct task_struct *dead_task)
extern asmlinkage void ret_from_fork(void);
/*
* copy_thread_tls
* copy_thread
* @clone_flags: flags
* @usp: user stack pointer or fn for kernel thread
* @arg: arg to fn for kernel thread; always NULL for userspace thread
@ -147,8 +147,8 @@ extern asmlinkage void ret_from_fork(void);
*/
int
copy_thread_tls(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p, unsigned long tls)
copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct pt_regs *userregs;
struct pt_regs *kregs;

1
arch/parisc/Kconfig
View File

@ -62,7 +62,6 @@ config PARISC
select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
select HAVE_KPROBES_ON_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_COPY_THREAD_TLS
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used

2
arch/parisc/kernel/process.c
View File

@ -208,7 +208,7 @@ arch_initcall(parisc_idle_init);
* Copy architecture-specific thread state
*/
int
copy_thread_tls(unsigned long clone_flags, unsigned long usp,
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
{
struct pt_regs *cregs = &(p->thread.regs);

1
arch/powerpc/Kconfig
View File

@ -186,7 +186,6 @@ config PPC
select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2)
select HAVE_CONTEXT_TRACKING if PPC64
select HAVE_TIF_NOHZ if PPC64
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_KMEMLEAK
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_DYNAMIC_FTRACE

2
arch/powerpc/kernel/process.c
View File

@ -1593,7 +1593,7 @@ static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
/*
* Copy architecture-specific thread state
*/
int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p,
unsigned long tls)
{

1
arch/riscv/Kconfig
View File

@ -54,7 +54,6 @@ config RISCV
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
select HAVE_ASM_MODVERSIONS
select HAVE_COPY_THREAD_TLS
select HAVE_DMA_CONTIGUOUS if MMU
select HAVE_EBPF_JIT if MMU
select HAVE_FUTEX_CMPXCHG if FUTEX

4
arch/riscv/kernel/process.c
View File

@ -101,8 +101,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
return 0;
}
int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p, unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);

1
arch/s390/Kconfig
View File

@ -136,7 +136,6 @@ config S390
select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE

4
arch/s390/kernel/process.c
View File

@ -80,8 +80,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
return 0;
}
int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp,
unsigned long arg, struct task_struct *p, unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
unsigned long arg, struct task_struct *p, unsigned long tls)
{
struct fake_frame
{

6
arch/sh/kernel/process_32.c
View File

@ -115,8 +115,8 @@ EXPORT_SYMBOL(dump_fpu);
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
@ -158,7 +158,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
ti->addr_limit = USER_DS;
if (clone_flags & CLONE_SETTLS)
childregs->gbr = childregs->regs[0];
childregs->gbr = tls;
childregs->regs[0] = 0; /* Set return value for child */
p->thread.pc = (unsigned long) ret_from_fork;

7
arch/sparc/include/asm/syscalls.h
View File

@ -4,9 +4,8 @@
struct pt_regs;
asmlinkage long sparc_do_fork(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size);
asmlinkage long sparc_fork(struct pt_regs *regs);
asmlinkage long sparc_vfork(struct pt_regs *regs);
asmlinkage long sparc_clone(struct pt_regs *regs);
#endif /* _SPARC64_SYSCALLS_H */

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() 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() 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() 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;
}

33
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
@ -300,8 +273,8 @@ asmlinkage int sparc_do_fork(unsigned long clone_flags,
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs, *regs = current_pt_regs();
@ -403,7 +376,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
regs->u_regs[UREG_I1] = 0;
if (clone_flags & CLONE_SETTLS)
childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
childregs->u_regs[UREG_G7] = tls;
return 0;
}

40
arch/sparc/kernel/process_64.c
View File

@ -572,47 +572,13 @@ void fault_in_user_windows(struct pt_regs *regs)
force_sig(SIGSEGV);
}
asmlinkage long sparc_do_fork(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size)
{
int __user *parent_tid_ptr, *child_tid_ptr;
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
#ifdef CONFIG_COMPAT
if (test_thread_flag(TIF_32BIT)) {
parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
} else
#endif
{
parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
}
ret = do_fork(clone_flags, stack_start, stack_size,
parent_tid_ptr, 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
* Child --> %o0 == parents pid, %o1 == 1
*/
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct *p)
int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct thread_info *t = task_thread_info(p);
struct pt_regs *regs = current_pt_regs();
@ -670,7 +636,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
regs->u_regs[UREG_I1] = 0;
if (clone_flags & CLONE_SETTLS)
t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
t->kregs->u_regs[UREG_G7] = tls;
return 0;
}

23
arch/sparc/kernel/syscalls.S
View File

@ -86,19 +86,22 @@ sys32_rt_sigreturn:
* during system calls...
*/
.align 32
sys_vfork: /* Under Linux, vfork and fork are just special cases of clone. */
sethi %hi(0x4000 | 0x0100 | SIGCHLD), %o0
or %o0, %lo(0x4000 | 0x0100 | SIGCHLD), %o0
ba,pt %xcc, sys_clone
sys_vfork:
flushw
ba,pt %xcc, sparc_vfork
add %sp, PTREGS_OFF, %o0
.align 32
sys_fork:
clr %o1
mov SIGCHLD, %o0
flushw
ba,pt %xcc, sparc_fork
add %sp, PTREGS_OFF, %o0
.align 32
sys_clone:
flushw
movrz %o1, %fp, %o1
mov 0, %o3
ba,pt %xcc, sparc_do_fork
add %sp, PTREGS_OFF, %o2
ba,pt %xcc, sparc_clone
add %sp, PTREGS_OFF, %o0
.globl ret_from_fork
ret_from_fork:

1
arch/um/Kconfig
View File

@ -14,7 +14,6 @@ config UML
select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_DEBUG_KMEMLEAK
select HAVE_DEBUG_BUGVERBOSE
select HAVE_COPY_THREAD_TLS
select GENERIC_IRQ_SHOW
select GENERIC_CPU_DEVICES
select GENERIC_CLOCKEVENTS

2
arch/um/kernel/process.c
View File

@ -152,7 +152,7 @@ void fork_handler(void)
userspace(&current->thread.regs.regs, current_thread_info()->aux_fp_regs);
}
int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct * p, unsigned long tls)
{
void (*handler)(void);

1
arch/x86/Kconfig
View File

@ -161,7 +161,6 @@ config X86
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_CONTEXT_TRACKING if X86_64
select HAVE_COPY_THREAD_TLS
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS

4
arch/x86/kernel/process.c
View File

@ -121,8 +121,8 @@ static int set_new_tls(struct task_struct *p, unsigned long tls)
return do_set_thread_area_64(p, ARCH_SET_FS, tls);
}
int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct *p, unsigned long tls)
int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
struct inactive_task_frame *frame;
struct fork_frame *fork_frame;

3
arch/x86/kernel/sys_ia32.c
View File

@ -251,9 +251,6 @@ COMPAT_SYSCALL_DEFINE5(ia32_clone, unsigned long, clone_flags,
.tls = tls_val,
};
if (!legacy_clone_args_valid(&args))
return -EINVAL;
return _do_fork(&args);
}
#endif /* CONFIG_IA32_EMULATION */

2
arch/x86/kernel/unwind_frame.c
View File

@ -269,7 +269,7 @@ bool unwind_next_frame(struct unwind_state *state)
/*
* kthreads (other than the boot CPU's idle thread) have some
* partial regs at the end of their stack which were placed
* there by copy_thread_tls(). But the regs don't have any
* there by copy_thread(). But the regs don't have any
* useful information, so we can skip them.
*
* This user_mode() check is slightly broader than a PF_KTHREAD

1
arch/xtensa/Kconfig
View File

@ -24,7 +24,6 @@ config XTENSA
select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
select HAVE_ARCH_TRACEHOOK
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_EXIT_THREAD

2
arch/xtensa/kernel/process.c
View File

@ -201,7 +201,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
* involved. Much simpler to just not copy those live frames across.
*/
int copy_thread_tls(unsigned long clone_flags, unsigned long usp_thread_fn,
int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
unsigned long thread_fn_arg, struct task_struct *p,
unsigned long tls)
{

17
include/linux/sched/task.h
View File

@ -66,22 +66,9 @@ extern void fork_init(void);
extern void release_task(struct task_struct * p);
#ifdef CONFIG_HAVE_COPY_THREAD_TLS
extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
struct task_struct *, unsigned long);
#else
extern int copy_thread(unsigned long, unsigned long, unsigned long,
struct task_struct *);
struct task_struct *, unsigned long);
/* Architectures that haven't opted into copy_thread_tls get the tls argument
* via pt_regs, so ignore the tls argument passed via C. */
static inline int copy_thread_tls(
unsigned long clone_flags, unsigned long sp, unsigned long arg,
struct task_struct *p, unsigned long tls)
{
return copy_thread(clone_flags, sp, arg, p);
}
#endif
extern void flush_thread(void);
#ifdef CONFIG_HAVE_EXIT_THREAD
@ -97,8 +84,6 @@ extern void exit_files(struct task_struct *);
extern void exit_itimers(struct signal_struct *);
extern long _do_fork(struct kernel_clone_args *kargs);
extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
struct task_struct *fork_idle(int);
struct mm_struct *copy_init_mm(void);
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);

67
kernel/fork.c
View File

@ -2097,8 +2097,7 @@ static __latent_entropy struct task_struct *copy_process(
retval = copy_io(clone_flags, p);
if (retval)
goto bad_fork_cleanup_namespaces;
retval = copy_thread_tls(clone_flags, args->stack, args->stack_size, p,
args->tls);
retval = copy_thread(clone_flags, args->stack, args->stack_size, p, args->tls);
if (retval)
goto bad_fork_cleanup_io;
@ -2416,6 +2415,20 @@ long _do_fork(struct kernel_clone_args *args)
int trace = 0;
long nr;
/*
* For legacy clone() calls, CLONE_PIDFD uses the parent_tid argument
* to return the pidfd. Hence, CLONE_PIDFD and CLONE_PARENT_SETTID are
* mutually exclusive. With clone3() CLONE_PIDFD has grown a separate
* field in struct clone_args and it still doesn't make sense to have
* them both point at the same memory location. Performing this check
* here has the advantage that we don't need to have a separate helper
* to check for legacy clone().
*/
if ((args->flags & CLONE_PIDFD) &&
(args->flags & CLONE_PARENT_SETTID) &&
(args->pidfd == args->parent_tid))
return -EINVAL;
/*
* Determine whether and which event to report to ptracer. When
* called from kernel_thread or CLONE_UNTRACED is explicitly
@ -2473,42 +2486,6 @@ long _do_fork(struct kernel_clone_args *args)
return nr;
}
bool legacy_clone_args_valid(const struct kernel_clone_args *kargs)
{
/* clone(CLONE_PIDFD) uses parent_tidptr to return a pidfd */
if ((kargs->flags & CLONE_PIDFD) &&
(kargs->flags & CLONE_PARENT_SETTID))
return false;
return true;
}
#ifndef CONFIG_HAVE_COPY_THREAD_TLS
/* For compatibility with architectures that call do_fork directly rather than
* using the syscall entry points below. */
long do_fork(unsigned long clone_flags,
unsigned long stack_start,
unsigned long stack_size,
int __user *parent_tidptr,
int __user *child_tidptr)
{
struct kernel_clone_args args = {
.flags = (lower_32_bits(clone_flags) & ~CSIGNAL),
.pidfd = parent_tidptr,
.child_tid = child_tidptr,
.parent_tid = parent_tidptr,
.exit_signal = (lower_32_bits(clone_flags) & CSIGNAL),
.stack = stack_start,
.stack_size = stack_size,
};
if (!legacy_clone_args_valid(&args))
return -EINVAL;
return _do_fork(&args);
}
#endif
/*
* Create a kernel thread.
*/
@ -2587,24 +2564,12 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
.tls = tls,
};
if (!legacy_clone_args_valid(&args))
return -EINVAL;
return _do_fork(&args);
}
#endif
#ifdef __ARCH_WANT_SYS_CLONE3
/*
* copy_thread implementations handle CLONE_SETTLS by reading the TLS value from
* the registers containing the syscall arguments for clone. This doesn't work
* with clone3 since the TLS value is passed in clone_args instead.
*/
#ifndef CONFIG_HAVE_COPY_THREAD_TLS
#error clone3 requires copy_thread_tls support in arch
#endif
noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
struct clone_args __user *uargs,
size_t usize)
@ -2919,7 +2884,7 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
/*
* unshare allows a process to 'unshare' part of the process
* context which was originally shared using clone. copy_*
* functions used by do_fork() cannot be used here directly
* functions used by _do_fork() cannot be used here directly
* because they modify an inactive task_struct that is being
* constructed. Here we are modifying the current, active,
* task_struct.