Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:

 - avoid invoking overflow handler for uaccess watchpoints

 - fix incorrect clock_gettime64 availability

 - fix EFI crash in create_mapping_late()

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8988/1: mmu: fix crash in EFI calls due to p4d typo in create_mapping_late()
  ARM: 8987/1: VDSO: Fix incorrect clock_gettime64
  ARM: 8986/1: hw_breakpoint: Don't invoke overflow handler on uaccess watchpoints
This commit is contained in:
Linus Torvalds
2020-07-31 09:33:45 -07:00
3 changed files with 24 additions and 6 deletions

View File

@@ -683,6 +683,12 @@ static void disable_single_step(struct perf_event *bp)
arch_install_hw_breakpoint(bp);
}
static int watchpoint_fault_on_uaccess(struct pt_regs *regs,
struct arch_hw_breakpoint *info)
{
return !user_mode(regs) && info->ctrl.privilege == ARM_BREAKPOINT_USER;
}
static void watchpoint_handler(unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
@@ -742,16 +748,27 @@ static void watchpoint_handler(unsigned long addr, unsigned int fsr,
}
pr_debug("watchpoint fired: address = 0x%x\n", info->trigger);
/*
* If we triggered a user watchpoint from a uaccess routine,
* then handle the stepping ourselves since userspace really
* can't help us with this.
*/
if (watchpoint_fault_on_uaccess(regs, info))
goto step;
perf_bp_event(wp, regs);
/*
* If no overflow handler is present, insert a temporary
* mismatch breakpoint so we can single-step over the
* watchpoint trigger.
* Defer stepping to the overflow handler if one is installed.
* Otherwise, insert a temporary mismatch breakpoint so that
* we can single-step over the watchpoint trigger.
*/
if (is_default_overflow_handler(wp))
enable_single_step(wp, instruction_pointer(regs));
if (!is_default_overflow_handler(wp))
goto unlock;
step:
enable_single_step(wp, instruction_pointer(regs));
unlock:
rcu_read_unlock();
}

View File

@@ -184,6 +184,7 @@ static void __init patch_vdso(void *ehdr)
if (!cntvct_ok) {
vdso_nullpatch_one(&einfo, "__vdso_gettimeofday");
vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64");
}
}