Merge tag 'x86_urgent_for_v5.15_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Prevent a infinite loop in the MCE recovery on return to user space,
which was caused by a second MCE queueing work for the same page and
thereby creating a circular work list.
- Make kern_addr_valid() handle existing PMD entries, which are marked
not present in the higher level page table, correctly instead of
blindly dereferencing them.
- Pass a valid address to sanitize_phys(). This was caused by the
mixture of inclusive and exclusive ranges. memtype_reserve() expect
'end' being exclusive, but sanitize_phys() wants it inclusive. This
worked so far, but with end being the end of the physical address
space the fail is exposed.
- Increase the maximum supported GPIO numbers for 64bit. Newer SoCs
exceed the previous maximum.
* tag 'x86_urgent_for_v5.15_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Avoid infinite loop for copy from user recovery
x86/mm: Fix kern_addr_valid() to cope with existing but not present entries
x86/platform: Increase maximum GPIO number for X86_64
x86/pat: Pass valid address to sanitize_phys()
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4e001bb..dad7f85 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -339,6 +339,11 @@
config ARCH_HIBERNATION_POSSIBLE
def_bool y
+config ARCH_NR_GPIO
+ int
+ default 1024 if X86_64
+ default 512
+
config ARCH_SUSPEND_POSSIBLE
def_bool y
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 8cb7816..193204a 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1253,6 +1253,9 @@
static void kill_me_now(struct callback_head *ch)
{
+ struct task_struct *p = container_of(ch, struct task_struct, mce_kill_me);
+
+ p->mce_count = 0;
force_sig(SIGBUS);
}
@@ -1262,6 +1265,7 @@
int flags = MF_ACTION_REQUIRED;
int ret;
+ p->mce_count = 0;
pr_err("Uncorrected hardware memory error in user-access at %llx", p->mce_addr);
if (!p->mce_ripv)
@@ -1290,17 +1294,34 @@
}
}
-static void queue_task_work(struct mce *m, int kill_current_task)
+static void queue_task_work(struct mce *m, char *msg, int kill_current_task)
{
- current->mce_addr = m->addr;
- current->mce_kflags = m->kflags;
- current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV);
- current->mce_whole_page = whole_page(m);
+ int count = ++current->mce_count;
- if (kill_current_task)
- current->mce_kill_me.func = kill_me_now;
- else
- current->mce_kill_me.func = kill_me_maybe;
+ /* First call, save all the details */
+ if (count == 1) {
+ current->mce_addr = m->addr;
+ current->mce_kflags = m->kflags;
+ current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV);
+ current->mce_whole_page = whole_page(m);
+
+ if (kill_current_task)
+ current->mce_kill_me.func = kill_me_now;
+ else
+ current->mce_kill_me.func = kill_me_maybe;
+ }
+
+ /* Ten is likely overkill. Don't expect more than two faults before task_work() */
+ if (count > 10)
+ mce_panic("Too many consecutive machine checks while accessing user data", m, msg);
+
+ /* Second or later call, make sure page address matches the one from first call */
+ if (count > 1 && (current->mce_addr >> PAGE_SHIFT) != (m->addr >> PAGE_SHIFT))
+ mce_panic("Consecutive machine checks to different user pages", m, msg);
+
+ /* Do not call task_work_add() more than once */
+ if (count > 1)
+ return;
task_work_add(current, ¤t->mce_kill_me, TWA_RESUME);
}
@@ -1438,7 +1459,7 @@
/* If this triggers there is no way to recover. Die hard. */
BUG_ON(!on_thread_stack() || !user_mode(regs));
- queue_task_work(&m, kill_current_task);
+ queue_task_work(&m, msg, kill_current_task);
} else {
/*
@@ -1456,7 +1477,7 @@
}
if (m.kflags & MCE_IN_KERNEL_COPYIN)
- queue_task_work(&m, kill_current_task);
+ queue_task_work(&m, msg, kill_current_task);
}
out:
mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index a6e1176..3609822 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1432,18 +1432,18 @@
return 0;
p4d = p4d_offset(pgd, addr);
- if (p4d_none(*p4d))
+ if (!p4d_present(*p4d))
return 0;
pud = pud_offset(p4d, addr);
- if (pud_none(*pud))
+ if (!pud_present(*pud))
return 0;
if (pud_large(*pud))
return pfn_valid(pud_pfn(*pud));
pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd))
+ if (!pmd_present(*pmd))
return 0;
if (pmd_large(*pmd))
diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c
index 3112ca7..4ba2a3e 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/arch/x86/mm/pat/memtype.c
@@ -583,7 +583,12 @@
int err = 0;
start = sanitize_phys(start);
- end = sanitize_phys(end);
+
+ /*
+ * The end address passed into this function is exclusive, but
+ * sanitize_phys() expects an inclusive address.
+ */
+ end = sanitize_phys(end - 1) + 1;
if (start >= end) {
WARN(1, "%s failed: [mem %#010Lx-%#010Lx], req %s\n", __func__,
start, end - 1, cattr_name(req_type));
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e12b524..39039ce 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1471,6 +1471,7 @@
mce_whole_page : 1,
__mce_reserved : 62;
struct callback_head mce_kill_me;
+ int mce_count;
#endif
#ifdef CONFIG_KRETPROBES
