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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 12:02:25 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 12:02:25 +0900
commit42859eea96ba6beabfb0369a1eeffa3c7d2bd9cb (patch)
treefa38aeda0d6e7a4c48a882b166b8643594a1ad50 /arch/x86/kernel
parentf59b51fe3d3092c08d7d554ecb40db24011b2ebc (diff)
parentf322220d6159455da2b5a8a596d802c8695fed30 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/Makefile2
-rw-r--r--arch/x86/kernel/asm-offsets.c3
-rw-r--r--arch/x86/kernel/entry_32.S26
-rw-r--r--arch/x86/kernel/entry_64.S74
-rw-r--r--arch/x86/kernel/process.c65
-rw-r--r--arch/x86/kernel/process_32.c37
-rw-r--r--arch/x86/kernel/process_64.c35
-rw-r--r--arch/x86/kernel/signal.c4
-rw-r--r--arch/x86/kernel/sys_i386_32.c40
-rw-r--r--arch/x86/kernel/vm86_32.c6
10 files changed, 101 insertions, 191 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index a48ea05157d3..91ce48f05f9f 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -23,7 +23,7 @@ obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o
obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o
obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-y += probe_roms.o
-obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o
+obj-$(CONFIG_X86_32) += i386_ksyms_32.o
obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o
obj-y += syscall_$(BITS).o
obj-$(CONFIG_X86_64) += vsyscall_64.o
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 68de2dc962ec..28610822fb3c 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -69,4 +69,7 @@ void common(void) {
OFFSET(BP_kernel_alignment, boot_params, hdr.kernel_alignment);
OFFSET(BP_pref_address, boot_params, hdr.pref_address);
OFFSET(BP_code32_start, boot_params, hdr.code32_start);
+
+ BLANK();
+ DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
}
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 0750e3ba87c0..8f9ed1afde8f 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -299,6 +299,13 @@ ENTRY(ret_from_fork)
CFI_ENDPROC
END(ret_from_fork)
+ENTRY(ret_from_kernel_execve)
+ movl %eax, %esp
+ movl $0,PT_EAX(%esp)
+ GET_THREAD_INFO(%ebp)
+ jmp syscall_exit
+END(ret_from_kernel_execve)
+
/*
* Interrupt exit functions should be protected against kprobes
*/
@@ -323,8 +330,7 @@ ret_from_intr:
andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax
#else
/*
- * We can be coming here from a syscall done in the kernel space,
- * e.g. a failed kernel_execve().
+ * We can be coming here from child spawned by kernel_thread().
*/
movl PT_CS(%esp), %eax
andl $SEGMENT_RPL_MASK, %eax
@@ -732,7 +738,6 @@ ENDPROC(ptregs_##name)
PTREGSCALL1(iopl)
PTREGSCALL0(fork)
PTREGSCALL0(vfork)
-PTREGSCALL3(execve)
PTREGSCALL2(sigaltstack)
PTREGSCALL0(sigreturn)
PTREGSCALL0(rt_sigreturn)
@@ -1015,15 +1020,20 @@ END(spurious_interrupt_bug)
*/
.popsection
-ENTRY(kernel_thread_helper)
- pushl $0 # fake return address for unwinder
+ENTRY(ret_from_kernel_thread)
CFI_STARTPROC
- movl %edi,%eax
- call *%esi
+ pushl_cfi %eax
+ call schedule_tail
+ GET_THREAD_INFO(%ebp)
+ popl_cfi %eax
+ pushl_cfi $0x0202 # Reset kernel eflags
+ popfl_cfi
+ movl PT_EBP(%esp),%eax
+ call *PT_EBX(%esp)
call do_exit
ud2 # padding for call trace
CFI_ENDPROC
-ENDPROC(kernel_thread_helper)
+ENDPROC(ret_from_kernel_thread)
#ifdef CONFIG_XEN
/* Xen doesn't set %esp to be precisely what the normal sysenter
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 44531acd9a81..cdc790c78f32 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -554,7 +554,7 @@ ENTRY(ret_from_fork)
RESTORE_REST
testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread?
- jz retint_restore_args
+ jz 1f
testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET
jnz int_ret_from_sys_call
@@ -562,6 +562,16 @@ ENTRY(ret_from_fork)
RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET
jmp ret_from_sys_call # go to the SYSRET fastpath
+1:
+ subq $REST_SKIP, %rsp # move the stack pointer back
+ CFI_ADJUST_CFA_OFFSET REST_SKIP
+ movq %rbp, %rdi
+ call *%rbx
+ # exit
+ mov %eax, %edi
+ call do_exit
+ ud2 # padding for call trace
+
CFI_ENDPROC
END(ret_from_fork)
@@ -862,7 +872,6 @@ ENTRY(stub_execve)
PARTIAL_FRAME 0
SAVE_REST
FIXUP_TOP_OF_STACK %r11
- movq %rsp, %rcx
call sys_execve
RESTORE_TOP_OF_STACK %r11
movq %rax,RAX(%rsp)
@@ -912,8 +921,7 @@ ENTRY(stub_x32_execve)
PARTIAL_FRAME 0
SAVE_REST
FIXUP_TOP_OF_STACK %r11
- movq %rsp, %rcx
- call sys32_execve
+ call compat_sys_execve
RESTORE_TOP_OF_STACK %r11
movq %rax,RAX(%rsp)
RESTORE_REST
@@ -1318,51 +1326,19 @@ bad_gs:
jmp 2b
.previous
-ENTRY(kernel_thread_helper)
- pushq $0 # fake return address
- CFI_STARTPROC
- /*
- * Here we are in the child and the registers are set as they were
- * at kernel_thread() invocation in the parent.
- */
- call *%rsi
- # exit
- mov %eax, %edi
- call do_exit
- ud2 # padding for call trace
- CFI_ENDPROC
-END(kernel_thread_helper)
-
-/*
- * execve(). This function needs to use IRET, not SYSRET, to set up all state properly.
- *
- * C extern interface:
- * extern long execve(const char *name, char **argv, char **envp)
- *
- * asm input arguments:
- * rdi: name, rsi: argv, rdx: envp
- *
- * We want to fallback into:
- * extern long sys_execve(const char *name, char **argv,char **envp, struct pt_regs *regs)
- *
- * do_sys_execve asm fallback arguments:
- * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack
- */
-ENTRY(kernel_execve)
- CFI_STARTPROC
- FAKE_STACK_FRAME $0
- SAVE_ALL
- movq %rsp,%rcx
- call sys_execve
- movq %rax, RAX(%rsp)
- RESTORE_REST
- testq %rax,%rax
- je int_ret_from_sys_call
- RESTORE_ARGS
- UNFAKE_STACK_FRAME
- ret
- CFI_ENDPROC
-END(kernel_execve)
+ENTRY(ret_from_kernel_execve)
+ movq %rdi, %rsp
+ movl $0, RAX(%rsp)
+ // RESTORE_REST
+ movq 0*8(%rsp), %r15
+ movq 1*8(%rsp), %r14
+ movq 2*8(%rsp), %r13
+ movq 3*8(%rsp), %r12
+ movq 4*8(%rsp), %rbp
+ movq 5*8(%rsp), %rbx
+ addq $(6*8), %rsp
+ jmp int_ret_from_sys_call
+END(ret_from_kernel_execve)
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(call_softirq)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index dc3567e083f9..b644e1c765dc 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -293,71 +293,6 @@ sys_clone(unsigned long clone_flags, unsigned long newsp,
}
/*
- * This gets run with %si containing the
- * function to call, and %di containing
- * the "args".
- */
-extern void kernel_thread_helper(void);
-
-/*
- * Create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
- struct pt_regs regs;
-
- memset(&regs, 0, sizeof(regs));
-
- regs.si = (unsigned long) fn;
- regs.di = (unsigned long) arg;
-
-#ifdef CONFIG_X86_32
- regs.ds = __USER_DS;
- regs.es = __USER_DS;
- regs.fs = __KERNEL_PERCPU;
- regs.gs = __KERNEL_STACK_CANARY;
-#else
- regs.ss = __KERNEL_DS;
-#endif
-
- regs.orig_ax = -1;
- regs.ip = (unsigned long) kernel_thread_helper;
- regs.cs = __KERNEL_CS | get_kernel_rpl();
- regs.flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
-
- /* Ok, create the new process.. */
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/*
- * sys_execve() executes a new program.
- */
-long sys_execve(const char __user *name,
- const char __user *const __user *argv,
- const char __user *const __user *envp, struct pt_regs *regs)
-{
- long error;
- char *filename;
-
- filename = getname(name);
- error = PTR_ERR(filename);
- if (IS_ERR(filename))
- return error;
- error = do_execve(filename, argv, envp, regs);
-
-#ifdef CONFIG_X86_32
- if (error == 0) {
- /* Make sure we don't return using sysenter.. */
- set_thread_flag(TIF_IRET);
- }
-#endif
-
- putname(filename);
- return error;
-}
-
-/*
* Idle related variables and functions
*/
unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b9ff83c7135b..44e0bff38e72 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -57,6 +57,7 @@
#include <asm/switch_to.h>
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
/*
* Return saved PC of a blocked thread.
@@ -127,23 +128,39 @@ void release_thread(struct task_struct *dead_task)
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
- struct pt_regs *childregs;
+ struct pt_regs *childregs = task_pt_regs(p);
struct task_struct *tsk;
int err;
- childregs = task_pt_regs(p);
+ p->thread.sp = (unsigned long) childregs;
+ p->thread.sp0 = (unsigned long) (childregs+1);
+
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childregs, 0, sizeof(struct pt_regs));
+ p->thread.ip = (unsigned long) ret_from_kernel_thread;
+ task_user_gs(p) = __KERNEL_STACK_CANARY;
+ childregs->ds = __USER_DS;
+ childregs->es = __USER_DS;
+ childregs->fs = __KERNEL_PERCPU;
+ childregs->bx = sp; /* function */
+ childregs->bp = arg;
+ childregs->orig_ax = -1;
+ childregs->cs = __KERNEL_CS | get_kernel_rpl();
+ childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
+ p->fpu_counter = 0;
+ p->thread.io_bitmap_ptr = NULL;
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+ return 0;
+ }
*childregs = *regs;
childregs->ax = 0;
childregs->sp = sp;
- p->thread.sp = (unsigned long) childregs;
- p->thread.sp0 = (unsigned long) (childregs+1);
-
p->thread.ip = (unsigned long) ret_from_fork;
-
task_user_gs(p) = get_user_gs(regs);
p->fpu_counter = 0;
@@ -190,6 +207,12 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
regs->cs = __USER_CS;
regs->ip = new_ip;
regs->sp = new_sp;
+ regs->flags = X86_EFLAGS_IF;
+ /*
+ * force it to the iret return path by making it look as if there was
+ * some work pending.
+ */
+ set_thread_flag(TIF_NOTIFY_RESUME);
}
EXPORT_SYMBOL_GPL(start_thread);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 8a6d20ce1978..16c6365e2b86 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -146,29 +146,18 @@ static inline u32 read_32bit_tls(struct task_struct *t, int tls)
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
int err;
struct pt_regs *childregs;
struct task_struct *me = current;
- childregs = ((struct pt_regs *)
- (THREAD_SIZE + task_stack_page(p))) - 1;
- *childregs = *regs;
-
- childregs->ax = 0;
- if (user_mode(regs))
- childregs->sp = sp;
- else
- childregs->sp = (unsigned long)childregs;
-
+ p->thread.sp0 = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+ childregs = task_pt_regs(p);
p->thread.sp = (unsigned long) childregs;
- p->thread.sp0 = (unsigned long) (childregs+1);
p->thread.usersp = me->thread.usersp;
-
set_tsk_thread_flag(p, TIF_FORK);
-
p->fpu_counter = 0;
p->thread.io_bitmap_ptr = NULL;
@@ -178,6 +167,24 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs;
savesegment(es, p->thread.es);
savesegment(ds, p->thread.ds);
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childregs, 0, sizeof(struct pt_regs));
+ childregs->sp = (unsigned long)childregs;
+ childregs->ss = __KERNEL_DS;
+ childregs->bx = sp; /* function */
+ childregs->bp = arg;
+ childregs->orig_ax = -1;
+ childregs->cs = __KERNEL_CS | get_kernel_rpl();
+ childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
+ return 0;
+ }
+ *childregs = *regs;
+
+ childregs->ax = 0;
+ childregs->sp = sp;
err = -ENOMEM;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index b33144c8b309..29ad351804e9 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -840,10 +840,6 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
fire_user_return_notifiers();
-#ifdef CONFIG_X86_32
- clear_thread_flag(TIF_IRET);
-#endif /* CONFIG_X86_32 */
-
rcu_user_enter();
}
diff --git a/arch/x86/kernel/sys_i386_32.c b/arch/x86/kernel/sys_i386_32.c
deleted file mode 100644
index 0b0cb5fede19..000000000000
--- a/arch/x86/kernel/sys_i386_32.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * This file contains various random system calls that
- * have a non-standard calling sequence on the Linux/i386
- * platform.
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/smp.h>
-#include <linux/sem.h>
-#include <linux/msg.h>
-#include <linux/shm.h>
-#include <linux/stat.h>
-#include <linux/syscalls.h>
-#include <linux/mman.h>
-#include <linux/file.h>
-#include <linux/utsname.h>
-#include <linux/ipc.h>
-
-#include <linux/uaccess.h>
-#include <linux/unistd.h>
-
-#include <asm/syscalls.h>
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
- const char *const argv[],
- const char *const envp[])
-{
- long __res;
- asm volatile ("int $0x80"
- : "=a" (__res)
- : "0" (__NR_execve), "b" (filename), "c" (argv), "d" (envp) : "memory");
- return __res;
-}
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 54abcc0baf23..5c9687b1bde6 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -561,9 +561,9 @@ int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno)
if ((trapno == 3) || (trapno == 1)) {
KVM86->regs32->ax = VM86_TRAP + (trapno << 8);
/* setting this flag forces the code in entry_32.S to
- call save_v86_state() and change the stack pointer
- to KVM86->regs32 */
- set_thread_flag(TIF_IRET);
+ the path where we call save_v86_state() and change
+ the stack pointer to KVM86->regs32 */
+ set_thread_flag(TIF_NOTIFY_RESUME);
return 0;
}
do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs));

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