diff options
Diffstat (limited to 'arch/i386/kernel/process.c')
| -rw-r--r-- | arch/i386/kernel/process.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index ae924c416b6..905364d4284 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -56,6 +56,7 @@ #include <asm/tlbflush.h> #include <asm/cpu.h> +#include <asm/pda.h> asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); @@ -346,6 +347,7 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) regs.xds = __USER_DS; regs.xes = __USER_DS; + regs.xgs = __KERNEL_PDA; regs.orig_eax = -1; regs.eip = (unsigned long) kernel_thread_helper; regs.xcs = __KERNEL_CS | get_kernel_rpl(); @@ -431,7 +433,6 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp, p->thread.eip = (unsigned long) ret_from_fork; savesegment(fs,p->thread.fs); - savesegment(gs,p->thread.gs); tsk = current; if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) { @@ -659,16 +660,16 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas load_esp0(tss, next); /* - * Save away %fs and %gs. No need to save %es and %ds, as - * those are always kernel segments while inside the kernel. - * Doing this before setting the new TLS descriptors avoids - * the situation where we temporarily have non-reloadable - * segments in %fs and %gs. This could be an issue if the - * NMI handler ever used %fs or %gs (it does not today), or - * if the kernel is running inside of a hypervisor layer. + * Save away %fs. No need to save %gs, as it was saved on the + * stack on entry. No need to save %es and %ds, as those are + * always kernel segments while inside the kernel. Doing this + * before setting the new TLS descriptors avoids the situation + * where we temporarily have non-reloadable segments in %fs + * and %gs. This could be an issue if the NMI handler ever + * used %fs or %gs (it does not today), or if the kernel is + * running inside of a hypervisor layer. */ savesegment(fs, prev->fs); - savesegment(gs, prev->gs); /* * Load the per-thread Thread-Local Storage descriptor. @@ -676,16 +677,13 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas load_TLS(next, cpu); /* - * Restore %fs and %gs if needed. + * Restore %fs if needed. * - * Glibc normally makes %fs be zero, and %gs is one of - * the TLS segments. + * Glibc normally makes %fs be zero. */ if (unlikely(prev->fs | next->fs)) loadsegment(fs, next->fs); - if (prev->gs | next->gs) - loadsegment(gs, next->gs); /* * Restore IOPL if needed. |