2ebc3cc920
The function arch_vma_name() is declared weak and thus it was not noticed that x86_64 had two almost identical implementations. It was introduced in syscall32.c by:c633090e31It was introduced in mm/init.c by:2aae950b21Signed-off-by: Roland McGrath <roland@redhat.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 lines
2.4 KiB
C
84 lines
2.4 KiB
C
/* Copyright 2002,2003 Andi Kleen, SuSE Labs */
|
|
|
|
/* vsyscall handling for 32bit processes. Map a stub page into it
|
|
on demand because 32bit cannot reach the kernel's fixmaps */
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/string.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/init.h>
|
|
#include <linux/stringify.h>
|
|
#include <linux/security.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/ia32_unistd.h>
|
|
#include <asm/vsyscall32.h>
|
|
|
|
extern unsigned char syscall32_syscall[], syscall32_syscall_end[];
|
|
extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[];
|
|
extern int sysctl_vsyscall32;
|
|
|
|
static struct page *syscall32_pages[1];
|
|
static int use_sysenter = -1;
|
|
|
|
struct linux_binprm;
|
|
|
|
/* Setup a VMA at program startup for the vsyscall page */
|
|
int syscall32_setup_pages(struct linux_binprm *bprm, int exstack)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
int ret;
|
|
|
|
down_write(&mm->mmap_sem);
|
|
/*
|
|
* MAYWRITE to allow gdb to COW and set breakpoints
|
|
*
|
|
* Make sure the vDSO gets into every core dump.
|
|
* Dumping its contents makes post-mortem fully interpretable later
|
|
* without matching up the same kernel and hardware config to see
|
|
* what PC values meant.
|
|
*/
|
|
/* Could randomize here */
|
|
ret = install_special_mapping(mm, VSYSCALL32_BASE, PAGE_SIZE,
|
|
VM_READ|VM_EXEC|
|
|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
|
|
VM_ALWAYSDUMP,
|
|
syscall32_pages);
|
|
up_write(&mm->mmap_sem);
|
|
return ret;
|
|
}
|
|
|
|
static int __init init_syscall32(void)
|
|
{
|
|
char *syscall32_page = (void *)get_zeroed_page(GFP_KERNEL);
|
|
if (!syscall32_page)
|
|
panic("Cannot allocate syscall32 page");
|
|
syscall32_pages[0] = virt_to_page(syscall32_page);
|
|
if (use_sysenter > 0) {
|
|
memcpy(syscall32_page, syscall32_sysenter,
|
|
syscall32_sysenter_end - syscall32_sysenter);
|
|
} else {
|
|
memcpy(syscall32_page, syscall32_syscall,
|
|
syscall32_syscall_end - syscall32_syscall);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
__initcall(init_syscall32);
|
|
|
|
/* May not be __init: called during resume */
|
|
void syscall32_cpu_init(void)
|
|
{
|
|
if (use_sysenter < 0)
|
|
use_sysenter = (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL);
|
|
|
|
/* Load these always in case some future AMD CPU supports
|
|
SYSENTER from compat mode too. */
|
|
checking_wrmsrl(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
|
|
checking_wrmsrl(MSR_IA32_SYSENTER_ESP, 0ULL);
|
|
checking_wrmsrl(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
|
|
|
|
wrmsrl(MSR_CSTAR, ia32_cstar_target);
|
|
}
|