x86/ldt: Make LDT pgtable free conditional

Andy prefers to be paranoid about the pagetable free in the error path of
write_ldt(). Make it conditional and warn whenever the installment of a
secondary LDT fails.

Requested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2017-12-31 16:52:15 +01:00
parent a62d69857a
commit 7f414195b0

View file

@ -426,7 +426,8 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
* already installed then the PTE page is already
* populated. Mop up a half populated page table.
*/
free_ldt_pgtables(mm);
if (!WARN_ON_ONCE(old_ldt))
free_ldt_pgtables(mm);
free_ldt_struct(new_ldt);
goto out_unlock;
}