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authorLinus Torvalds <torvalds@linux-foundation.org>2020-07-31 09:33:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-07-31 09:33:45 -0700
commitc1954ca6abdc69a02a768368eb31882e92cf5bfa (patch)
tree1138c65f49c19b8e45352645a43cdada944bfbd6
parentae2911de2eb5dc9ccb88c6502c776a8fbb7acc67 (diff)
parent5c6360ee4a0e7f62de34341ad5d3c936f49b391d (diff)
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
-rw-r--r--arch/arm/kernel/hw_breakpoint.c27
-rw-r--r--arch/arm/kernel/vdso.c1
-rw-r--r--arch/arm/mm/mmu.c2
3 files changed, 24 insertions, 6 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 02ca7adf5375..7fff88e61252 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -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();
}
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 6bfdca4769a7..fddd08a6e063 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -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");
}
}
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 628028bfbb92..bcd82614c25d 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -966,7 +966,7 @@ void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md,
pud_t *pud;
p4d = p4d_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
- if (!WARN_ON(!p4d))
+ if (WARN_ON(!p4d))
return;
pud = pud_alloc(mm, p4d, md->virtual);
if (WARN_ON(!pud))