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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-19 13:29:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-19 13:29:36 -0700
commit20621d2f27a0163b81dc2b74fd4c0b3e6aa5fa12 (patch)
treed1bbb8f8498d0b16e1410a6b25c636a8b838a74a /arch
parentfec3036200b7d9df32c94eb2616447eb2f6e09ac (diff)
parent81065b35e2486c024c7aa86caed452e1f01a59d4 (diff)
downloadlinux-20621d2f27a0163b81dc2b74fd4c0b3e6aa5fa12.tar.bz2
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()
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/Kconfig5
-rw-r--r--arch/x86/kernel/cpu/mce/core.c43
-rw-r--r--arch/x86/mm/init_64.c6
-rw-r--r--arch/x86/mm/pat/memtype.c7
4 files changed, 46 insertions, 15 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4e001bbbb425..dad7f85dcdea 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -339,6 +339,11 @@ config NEED_PER_CPU_PAGE_FIRST_CHUNK
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 8cb7816d03b4..193204aee880 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1253,6 +1253,9 @@ static void __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *fin
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 @@ static void kill_me_maybe(struct callback_head *cb)
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 kill_me_maybe(struct callback_head *cb)
}
}
-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, &current->mce_kill_me, TWA_RESUME);
}
@@ -1438,7 +1459,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
/* 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 @@ noinstr void do_machine_check(struct pt_regs *regs)
}
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 a6e11763763f..36098226a957 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1432,18 +1432,18 @@ int kern_addr_valid(unsigned long addr)
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 3112ca7786ed..4ba2a3ee4bce 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/arch/x86/mm/pat/memtype.c
@@ -583,7 +583,12 @@ int memtype_reserve(u64 start, u64 end, enum page_cache_mode req_type,
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));