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Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r--arch/x86/kernel/process_64.c86
1 files changed, 52 insertions, 34 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 61cdf7fdf09..ca5b02d405c 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -52,7 +52,7 @@
asmlinkage extern void ret_from_fork(void);
-DEFINE_PER_CPU(unsigned long, old_rsp);
+__visible DEFINE_PER_CPU(unsigned long, old_rsp);
/* Prints also some state that isn't saved in the pt_regs */
void __show_regs(struct pt_regs *regs, int all)
@@ -62,9 +62,8 @@ void __show_regs(struct pt_regs *regs, int all)
unsigned int fsindex, gsindex;
unsigned int ds, cs, es;
- show_regs_common();
printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
- printk_address(regs->ip, 1);
+ printk_address(regs->ip);
printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
regs->sp, regs->flags);
printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
@@ -106,21 +105,28 @@ void __show_regs(struct pt_regs *regs, int all)
get_debugreg(d0, 0);
get_debugreg(d1, 1);
get_debugreg(d2, 2);
- printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
get_debugreg(d3, 3);
get_debugreg(d6, 6);
get_debugreg(d7, 7);
+
+ /* Only print out debug registers if they are in their non-default state. */
+ if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) &&
+ (d6 == DR6_RESERVED) && (d7 == 0x400))
+ return;
+
+ printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
+
}
void release_thread(struct task_struct *dead_task)
{
if (dead_task->mm) {
if (dead_task->mm->context.size) {
- printk("WARNING: dead process %8s still has LDT? <%p/%d>\n",
- dead_task->comm,
- dead_task->mm->context.ldt,
- dead_task->mm->context.size);
+ pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n",
+ dead_task->comm,
+ dead_task->mm->context.ldt,
+ dead_task->mm->context.size);
BUG();
}
}
@@ -146,30 +152,18 @@ 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,
- struct task_struct *p, struct pt_regs *regs)
+ unsigned long arg, struct task_struct *p)
{
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.fpu_counter = 0;
p->thread.io_bitmap_ptr = NULL;
savesegment(gs, p->thread.gsindex);
@@ -178,6 +172,25 @@ 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(p->flags & PF_KTHREAD)) {
+ /* 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_FIXED;
+ return 0;
+ }
+ *childregs = *current_pt_regs();
+
+ childregs->ax = 0;
+ if (sp)
+ childregs->sp = sp;
err = -ENOMEM;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
@@ -232,10 +245,6 @@ start_thread_common(struct pt_regs *regs, unsigned long new_ip,
regs->cs = _cs;
regs->ss = _ss;
regs->flags = X86_EFLAGS_IF;
- /*
- * Free the old FP and other extended state
- */
- free_thread_xstate(current);
}
void
@@ -265,7 +274,7 @@ void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)
* Kprobes not supported here. Set the probe on schedule instead.
* Function graph tracer not supported too.
*/
-__notrace_funcgraph struct task_struct *
+__visible __notrace_funcgraph struct task_struct *
__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
{
struct thread_struct *prev = &prev_p->thread;
@@ -354,6 +363,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
this_cpu_write(old_rsp, next->usersp);
this_cpu_write(current_task, next_p);
+ /*
+ * If it were not for PREEMPT_ACTIVE we could guarantee that the
+ * preempt_count of all tasks was equal here and this would not be
+ * needed.
+ */
+ task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count);
+ this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count);
+
this_cpu_write(kernel_stack,
(unsigned long)task_stack_page(next_p) +
THREAD_SIZE - KERNEL_STACK_OFFSET);
@@ -396,12 +413,11 @@ void set_personality_ia32(bool x32)
set_thread_flag(TIF_ADDR32);
/* Mark the associated mm as containing 32-bit tasks. */
- if (current->mm)
- current->mm->context.ia32_compat = 1;
-
if (x32) {
clear_thread_flag(TIF_IA32);
set_thread_flag(TIF_X32);
+ if (current->mm)
+ current->mm->context.ia32_compat = TIF_X32;
current->personality &= ~READ_IMPLIES_EXEC;
/* is_compat_task() uses the presence of the x32
syscall bit flag to determine compat status */
@@ -409,6 +425,8 @@ void set_personality_ia32(bool x32)
} else {
set_thread_flag(TIF_IA32);
clear_thread_flag(TIF_X32);
+ if (current->mm)
+ current->mm->context.ia32_compat = TIF_IA32;
current->personality |= force_personality32;
/* Prepare the first "return" to user space */
current_thread_info()->status |= TS_COMPAT;
@@ -466,7 +484,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
task->thread.gs = addr;
if (doit) {
load_gs_index(0);
- ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
+ ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr);
}
}
put_cpu();
@@ -494,7 +512,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
/* set the selector to 0 to not confuse
__switch_to */
loadsegment(fs, 0);
- ret = checking_wrmsrl(MSR_FS_BASE, addr);
+ ret = wrmsrl_safe(MSR_FS_BASE, addr);
}
}
put_cpu();
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 19:14:59 +0000