mirror of https://gitee.com/openkylin/linux.git
ef5cbcb6bf
Fault paths like do_read_fault will install a Linux pte with the young bit clear. The CPU will fault again because the TLB has not been updated, this time a valid pte exists so handle_pte_fault will just set the young bit with ptep_set_access_flags, which flushes the TLB. The TLB is flushed so the next attempt will go to the fast TLB handler which loads the TLB with the new Linux pte. The access then proceeds. This design is fragile to depend on the young bit being clear after the initial Linux fault. A proposed core mm change to immediately set the young bit upon such a fault, results in ptep_set_access_flags not flushing the TLB because it finds no change to the pte. The spurious fault fix path only flushes the TLB if the access was a store. If it was a load, then this results in an infinite loop of page faults. This change adds a TLB flush in update_mmu_cache, which removes that TLB entry upon the first fault. This will cause the fast TLB handler to load the new pte and avoid the Linux page fault entirely. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com> |
||
|---|---|---|
| .. | ||
| alpha | ||
| arc | ||
| arm | ||
| arm64 | ||
| c6x | ||
| csky | ||
| h8300 | ||
| hexagon | ||
| ia64 | ||
| m68k | ||
| microblaze | ||
| mips | ||
| nds32 | ||
| nios2 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| riscv | ||
| s390 | ||
| sh | ||
| sparc | ||
| um | ||
| unicore32 | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||