From: Arnd Bergmann <arnd(a)arndb.de>
The unusual function calling conventions on superh ended up causing
sync_file_range to have the wrong argument order, with the 'flags'
argument getting sorted before 'nbytes' by the compiler.
In userspace, I found that musl, glibc, uclibc and strace all expect the
normal calling conventions with 'nbytes' last, so changing the kernel
to match them should make all of those work.
In order to be able to also fix libc implementations to work with existing
kernels, they need to be able to tell which ABI is used. An easy way
to do this is to add yet another system call using the sync_file_range2
ABI that works the same on all architectures.
Old user binaries can now work on new kernels, and new binaries can
try the new sync_file_range2() to work with new kernels or fall back
to the old sync_file_range() version if that doesn't exist.
Cc: stable(a)vger.kernel.org
Fixes: 75c92acdd5b1 ("sh: Wire up new syscalls.")
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
arch/sh/kernel/sys_sh32.c | 11 +++++++++++
arch/sh/kernel/syscalls/syscall.tbl | 3 ++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/sh/kernel/sys_sh32.c b/arch/sh/kernel/sys_sh32.c
index 9dca568509a5..d5a4f7c697d8 100644
--- a/arch/sh/kernel/sys_sh32.c
+++ b/arch/sh/kernel/sys_sh32.c
@@ -59,3 +59,14 @@ asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
(u64)len0 << 32 | len1, advice);
#endif
}
+
+/*
+ * swap the arguments the way that libc wants it instead of
+ * moving flags ahead of the 64-bit nbytes argument
+ */
+SYSCALL_DEFINE6(sh_sync_file_range6, int, fd, SC_ARG64(offset),
+ SC_ARG64(nbytes), unsigned int, flags)
+{
+ return ksys_sync_file_range(fd, SC_VAL64(loff_t, offset),
+ SC_VAL64(loff_t, nbytes), flags);
+}
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index bbf83a2db986..c55fd7696d40 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -321,7 +321,7 @@
311 common set_robust_list sys_set_robust_list
312 common get_robust_list sys_get_robust_list
313 common splice sys_splice
-314 common sync_file_range sys_sync_file_range
+314 common sync_file_range sys_sh_sync_file_range6
315 common tee sys_tee
316 common vmsplice sys_vmsplice
317 common move_pages sys_move_pages
@@ -395,6 +395,7 @@
385 common pkey_alloc sys_pkey_alloc
386 common pkey_free sys_pkey_free
387 common rseq sys_rseq
+388 common sync_file_range2 sys_sync_file_range2
# room for arch specific syscalls
393 common semget sys_semget
394 common semctl sys_semctl
--
2.39.2
According to the code logic, when the kernel is loaded to address 0,
no copying operation should be performed, but it is currently being
done.
This patch fixes the issue where the kernel code was incorrectly
duplicated to address 0 when booting from address 0.
Fixes: b270bebd34e3 ("powerpc/64s: Run at the kernel virtual address earlier in boot")
Signed-off-by: Jinglin Wen <jinglin.wen(a)shingroup.cn>
Suggested-by: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: <stable(a)vger.kernel.org>
---
v2:
- According to 87le336c6k.fsf(a)mail.lhotse, improve this patch.
v1:
- 20240617023509.5674-1-jinglin.wen(a)shingroup.cn
arch/powerpc/kernel/head_64.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 4690c219bfa4..63432a33ec49 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -647,8 +647,9 @@ __after_prom_start:
* Note: This process overwrites the OF exception vectors.
*/
LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET)
- mr. r4,r26 /* In some cases the loader may */
- beq 9f /* have already put us at zero */
+ mr r4,r26 /* Load the virtual source address into r4 */
+ cmpld r3,r4 /* Check if source == dest */
+ beq 9f /* If so skip the copy */
li r6,0x100 /* Start offset, the first 0x100 */
/* bytes were copied earlier. */
--
2.25.1
Rename tdx_parse_tdinfo() to tdx_setup() and move setting NOTIFY_ENABLES
there.
The function will be extended to adjust TD configuration.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy(a)linux.intel.com>
Reviewed-by: Kai Huang <kai.huang(a)intel.com>
Cc: stable(a)vger.kernel.org
---
arch/x86/coco/tdx/tdx.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 64717a96a936..08ce488b54d0 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -193,7 +193,7 @@ static void __noreturn tdx_panic(const char *msg)
__tdx_hypercall(&args);
}
-static void tdx_parse_tdinfo(u64 *cc_mask)
+static void tdx_setup(u64 *cc_mask)
{
struct tdx_module_args args = {};
unsigned int gpa_width;
@@ -218,6 +218,9 @@ static void tdx_parse_tdinfo(u64 *cc_mask)
gpa_width = args.rcx & GENMASK(5, 0);
*cc_mask = BIT_ULL(gpa_width - 1);
+ /* Kernel does not use NOTIFY_ENABLES and does not need random #VEs */
+ tdg_vm_wr(TDCS_NOTIFY_ENABLES, 0, -1ULL);
+
/*
* The kernel can not handle #VE's when accessing normal kernel
* memory. Ensure that no #VE will be delivered for accesses to
@@ -964,11 +967,11 @@ void __init tdx_early_init(void)
setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
cc_vendor = CC_VENDOR_INTEL;
- tdx_parse_tdinfo(&cc_mask);
- cc_set_mask(cc_mask);
- /* Kernel does not use NOTIFY_ENABLES and does not need random #VEs */
- tdg_vm_wr(TDCS_NOTIFY_ENABLES, 0, -1ULL);
+ /* Configure the TD */
+ tdx_setup(&cc_mask);
+
+ cc_set_mask(cc_mask);
/*
* All bits above GPA width are reserved and kernel treats shared bit
--
2.43.0
The TDG_VM_WR TDCALL is used to ask the TDX module to change some
TD-specific VM configuration. There is currently only one user in the
kernel of this TDCALL leaf. More will be added shortly.
Refactor to make way for more users of TDG_VM_WR who will need to modify
other TD configuration values.
Add a wrapper for the TDG_VM_RD TDCALL that requests TD-specific
metadata from the TDX module. There are currently no users for
TDG_VM_RD. Mark it as __maybe_unused until the first user appears.
This is preparation for enumeration and enabling optional TD features.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Reviewed-by: Kai Huang <kai.huang(a)intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy(a)linux.intel.com>
Cc: stable(a)vger.kernel.org
---
arch/x86/coco/tdx/tdx.c | 32 ++++++++++++++++++++++++++-----
arch/x86/include/asm/shared/tdx.h | 1 +
2 files changed, 28 insertions(+), 5 deletions(-)
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 078e2bac2553..64717a96a936 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -77,6 +77,32 @@ static inline void tdcall(u64 fn, struct tdx_module_args *args)
panic("TDCALL %lld failed (Buggy TDX module!)\n", fn);
}
+/* Read TD-scoped metadata */
+static inline u64 __maybe_unused tdg_vm_rd(u64 field, u64 *value)
+{
+ struct tdx_module_args args = {
+ .rdx = field,
+ };
+ u64 ret;
+
+ ret = __tdcall_ret(TDG_VM_RD, &args);
+ *value = args.r8;
+
+ return ret;
+}
+
+/* Write TD-scoped metadata */
+static inline u64 tdg_vm_wr(u64 field, u64 value, u64 mask)
+{
+ struct tdx_module_args args = {
+ .rdx = field,
+ .r8 = value,
+ .r9 = mask,
+ };
+
+ return __tdcall(TDG_VM_WR, &args);
+}
+
/**
* tdx_mcall_get_report0() - Wrapper to get TDREPORT0 (a.k.a. TDREPORT
* subtype 0) using TDG.MR.REPORT TDCALL.
@@ -924,10 +950,6 @@ static void tdx_kexec_finish(void)
void __init tdx_early_init(void)
{
- struct tdx_module_args args = {
- .rdx = TDCS_NOTIFY_ENABLES,
- .r9 = -1ULL,
- };
u64 cc_mask;
u32 eax, sig[3];
@@ -946,7 +968,7 @@ void __init tdx_early_init(void)
cc_set_mask(cc_mask);
/* Kernel does not use NOTIFY_ENABLES and does not need random #VEs */
- tdcall(TDG_VM_WR, &args);
+ tdg_vm_wr(TDCS_NOTIFY_ENABLES, 0, -1ULL);
/*
* All bits above GPA width are reserved and kernel treats shared bit
diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h
index fdfd41511b02..7e12cfa28bec 100644
--- a/arch/x86/include/asm/shared/tdx.h
+++ b/arch/x86/include/asm/shared/tdx.h
@@ -16,6 +16,7 @@
#define TDG_VP_VEINFO_GET 3
#define TDG_MR_REPORT 4
#define TDG_MEM_PAGE_ACCEPT 6
+#define TDG_VM_RD 7
#define TDG_VM_WR 8
/* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */
--
2.43.0
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 3a5a8d343e1cf96eb9971b17cbd4b832ab19b8e7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024061319-skater-sculptor-905f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
3a5a8d343e1c ("mm: fix race between __split_huge_pmd_locked() and GUP-fast")
4f83145721f3 ("mm: avoid unnecessary flush on change_huge_pmd()")
c9fe66560bf2 ("mm/mprotect: do not flush when not required architecturally")
4a18419f71cd ("mm/mprotect: use mmu_gather")
e346e6688c4a ("mm: thp: skip make PMD PROT_NONE if THP migration is not supported")
f0953a1bbaca ("mm: fix typos in comments")
e2db1a9aa381 ("kasan, mm: optimize kmalloc poisoning")
928501344fc6 ("kasan, mm: don't save alloc stacks twice")
2b8305260fb3 ("kfence, kasan: make KFENCE compatible with KASAN")
0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure")
41139aa4c3a3 ("mm/filemap: add mapping_seek_hole_data")
a1ba9da8f0f9 ("mm/hugetlb.c: fix unnecessary address expansion of pmd sharing")
611806b4bf8d ("kasan: fix bug detection via ksize for HW_TAGS mode")
027b37b552f3 ("kasan: move _RET_IP_ to inline wrappers")
573a48092313 ("kasan: add match-all tag tests")
f00748bfa024 ("kasan: prefix global functions with kasan_")
dbf53f7597be ("mm/mprotect.c: optimize error detection in do_mprotect_pkey()")
96667f8a4382 ("mm: Close race in generic_access_phys")
97593cad003c ("kasan: sanitize objects when metadata doesn't fit")
1ef3133bd3b8 ("kasan: simplify assign_tag and set_tag calls")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3a5a8d343e1cf96eb9971b17cbd4b832ab19b8e7 Mon Sep 17 00:00:00 2001
From: Ryan Roberts <ryan.roberts(a)arm.com>
Date: Wed, 1 May 2024 15:33:10 +0100
Subject: [PATCH] mm: fix race between __split_huge_pmd_locked() and GUP-fast
__split_huge_pmd_locked() can be called for a present THP, devmap or
(non-present) migration entry. It calls pmdp_invalidate() unconditionally
on the pmdp and only determines if it is present or not based on the
returned old pmd. This is a problem for the migration entry case because
pmd_mkinvalid(), called by pmdp_invalidate() must only be called for a
present pmd.
On arm64 at least, pmd_mkinvalid() will mark the pmd such that any future
call to pmd_present() will return true. And therefore any lockless
pgtable walker could see the migration entry pmd in this state and start
interpretting the fields as if it were present, leading to BadThings (TM).
GUP-fast appears to be one such lockless pgtable walker.
x86 does not suffer the above problem, but instead pmd_mkinvalid() will
corrupt the offset field of the swap entry within the swap pte. See link
below for discussion of that problem.
Fix all of this by only calling pmdp_invalidate() for a present pmd. And
for good measure let's add a warning to all implementations of
pmdp_invalidate[_ad](). I've manually reviewed all other
pmdp_invalidate[_ad]() call sites and believe all others to be conformant.
This is a theoretical bug found during code review. I don't have any test
case to trigger it in practice.
Link: https://lkml.kernel.org/r/20240501143310.1381675-1-ryan.roberts@arm.com
Link: https://lore.kernel.org/all/0dd7827a-6334-439a-8fd0-43c98e6af22b@arm.com/
Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com>
Reviewed-by: Zi Yan <ziy(a)nvidia.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual(a)arm.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Andreas Larsson <andreas(a)gaisler.com>
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org>
Cc: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu>
Cc: Dave Hansen <dave.hansen(a)linux.intel.com>
Cc: "David S. Miller" <davem(a)davemloft.net>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Jonathan Corbet <corbet(a)lwn.net>
Cc: Mark Rutland <mark.rutland(a)arm.com>
Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com>
Cc: Nicholas Piggin <npiggin(a)gmail.com>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Sven Schnelle <svens(a)linux.ibm.com>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Will Deacon <will(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/Documentation/mm/arch_pgtable_helpers.rst b/Documentation/mm/arch_pgtable_helpers.rst
index 2466d3363af7..ad50ca6f495e 100644
--- a/Documentation/mm/arch_pgtable_helpers.rst
+++ b/Documentation/mm/arch_pgtable_helpers.rst
@@ -140,7 +140,8 @@ PMD Page Table Helpers
+---------------------------+--------------------------------------------------+
| pmd_swp_clear_soft_dirty | Clears a soft dirty swapped PMD |
+---------------------------+--------------------------------------------------+
-| pmd_mkinvalid | Invalidates a mapped PMD [1] |
+| pmd_mkinvalid | Invalidates a present PMD; do not call for |
+| | non-present PMD [1] |
+---------------------------+--------------------------------------------------+
| pmd_set_huge | Creates a PMD huge mapping |
+---------------------------+--------------------------------------------------+
@@ -196,7 +197,8 @@ PUD Page Table Helpers
+---------------------------+--------------------------------------------------+
| pud_mkdevmap | Creates a ZONE_DEVICE mapped PUD |
+---------------------------+--------------------------------------------------+
-| pud_mkinvalid | Invalidates a mapped PUD [1] |
+| pud_mkinvalid | Invalidates a present PUD; do not call for |
+| | non-present PUD [1] |
+---------------------------+--------------------------------------------------+
| pud_set_huge | Creates a PUD huge mapping |
+---------------------------+--------------------------------------------------+
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 83823db3488b..2975ea0841ba 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -170,6 +170,7 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
{
unsigned long old_pmd;
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return __pmd(old_pmd);
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2cb2a2e7b34b..558902edbfec 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1769,8 +1769,10 @@ static inline pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
static inline pmd_t pmdp_invalidate(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
{
- pmd_t pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
+ pmd_t pmd;
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
+ pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
return pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
}
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index 19642f7ffb52..8648a50afe88 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -249,6 +249,7 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
{
pmd_t old, entry;
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID);
old = pmdp_establish(vma, address, pmdp, entry);
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 94767c82fc0d..93e54ba91fbf 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -631,6 +631,8 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma,
pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
+
/*
* No flush is necessary. Once an invalid PTE is established, the PTE's
* access and dirty bits cannot be updated.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 08e4f3343bcd..ccdcff73284a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2430,32 +2430,11 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
return __split_huge_zero_page_pmd(vma, haddr, pmd);
}
- /*
- * Up to this point the pmd is present and huge and userland has the
- * whole access to the hugepage during the split (which happens in
- * place). If we overwrite the pmd with the not-huge version pointing
- * to the pte here (which of course we could if all CPUs were bug
- * free), userland could trigger a small page size TLB miss on the
- * small sized TLB while the hugepage TLB entry is still established in
- * the huge TLB. Some CPU doesn't like that.
- * See http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum
- * 383 on page 105. Intel should be safe but is also warns that it's
- * only safe if the permission and cache attributes of the two entries
- * loaded in the two TLB is identical (which should be the case here).
- * But it is generally safer to never allow small and huge TLB entries
- * for the same virtual address to be loaded simultaneously. So instead
- * of doing "pmd_populate(); flush_pmd_tlb_range();" we first mark the
- * current pmd notpresent (atomically because here the pmd_trans_huge
- * must remain set at all times on the pmd until the split is complete
- * for this pmd), then we flush the SMP TLB and finally we write the
- * non-huge version of the pmd entry with pmd_populate.
- */
- old_pmd = pmdp_invalidate(vma, haddr, pmd);
-
- pmd_migration = is_pmd_migration_entry(old_pmd);
+ pmd_migration = is_pmd_migration_entry(*pmd);
if (unlikely(pmd_migration)) {
swp_entry_t entry;
+ old_pmd = *pmd;
entry = pmd_to_swp_entry(old_pmd);
page = pfn_swap_entry_to_page(entry);
write = is_writable_migration_entry(entry);
@@ -2466,6 +2445,30 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
soft_dirty = pmd_swp_soft_dirty(old_pmd);
uffd_wp = pmd_swp_uffd_wp(old_pmd);
} else {
+ /*
+ * Up to this point the pmd is present and huge and userland has
+ * the whole access to the hugepage during the split (which
+ * happens in place). If we overwrite the pmd with the not-huge
+ * version pointing to the pte here (which of course we could if
+ * all CPUs were bug free), userland could trigger a small page
+ * size TLB miss on the small sized TLB while the hugepage TLB
+ * entry is still established in the huge TLB. Some CPU doesn't
+ * like that. See
+ * http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum
+ * 383 on page 105. Intel should be safe but is also warns that
+ * it's only safe if the permission and cache attributes of the
+ * two entries loaded in the two TLB is identical (which should
+ * be the case here). But it is generally safer to never allow
+ * small and huge TLB entries for the same virtual address to be
+ * loaded simultaneously. So instead of doing "pmd_populate();
+ * flush_pmd_tlb_range();" we first mark the current pmd
+ * notpresent (atomically because here the pmd_trans_huge must
+ * remain set at all times on the pmd until the split is
+ * complete for this pmd), then we flush the SMP TLB and finally
+ * we write the non-huge version of the pmd entry with
+ * pmd_populate.
+ */
+ old_pmd = pmdp_invalidate(vma, haddr, pmd);
page = pmd_page(old_pmd);
folio = page_folio(page);
if (pmd_dirty(old_pmd)) {
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 4fcd959dcc4d..a78a4adf711a 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -198,6 +198,7 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp));
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return old;
@@ -208,6 +209,7 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
return pmdp_invalidate(vma, address, pmdp);
}
#endif
Avoid spurious link status logs that may ultimately be wrong; for example,
if the link is set to down with the cable plugged, then the cable is
unplugged and after this the link is set to up, the last new log that is
appearing is incorrectly telling that the link is up.
In order to avoid errors, show link status logs after link_reset
processing, and in order to avoid spurious as much as possible, only show
the link loss when some link status change is detected.
cc: stable(a)vger.kernel.org
Fixes: e2ca90c276e1 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver")
Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm(a)redhat.com>
---
v3:
- Add net as target tree in the subject.
- Use constant string instead of variable because no other value is possible.
v2: https://lore.kernel.org/netdev/20240618115054.101577-1-jtornosm@redhat.com/
- Fix the nits
v1: https://lore.kernel.org/netdev/20240617103405.654567-1-jtornosm@redhat.com/
drivers/net/usb/ax88179_178a.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index c2fb736f78b2..b034ef8a73ea 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -326,7 +326,8 @@ static void ax88179_status(struct usbnet *dev, struct urb *urb)
if (netif_carrier_ok(dev->net) != link) {
usbnet_link_change(dev, link, 1);
- netdev_info(dev->net, "ax88179 - Link status is: %d\n", link);
+ if (!link)
+ netdev_info(dev->net, "ax88179 - Link status is: 0\n");
}
}
@@ -1542,6 +1543,7 @@ static int ax88179_link_reset(struct usbnet *dev)
GMII_PHY_PHYSR, 2, &tmp16);
if (!(tmp16 & GMII_PHY_PHYSR_LINK)) {
+ netdev_info(dev->net, "ax88179 - Link status is: 0\n");
return 0;
} else if (GMII_PHY_PHYSR_GIGA == (tmp16 & GMII_PHY_PHYSR_SMASK)) {
mode |= AX_MEDIUM_GIGAMODE | AX_MEDIUM_EN_125MHZ;
@@ -1579,6 +1581,8 @@ static int ax88179_link_reset(struct usbnet *dev)
netif_carrier_on(dev->net);
+ netdev_info(dev->net, "ax88179 - Link status is: 1\n");
+
return 0;
}
--
2.45.1
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 3a5a8d343e1cf96eb9971b17cbd4b832ab19b8e7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024061316-brook-imaging-a202@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
3a5a8d343e1c ("mm: fix race between __split_huge_pmd_locked() and GUP-fast")
4f83145721f3 ("mm: avoid unnecessary flush on change_huge_pmd()")
c9fe66560bf2 ("mm/mprotect: do not flush when not required architecturally")
4a18419f71cd ("mm/mprotect: use mmu_gather")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3a5a8d343e1cf96eb9971b17cbd4b832ab19b8e7 Mon Sep 17 00:00:00 2001
From: Ryan Roberts <ryan.roberts(a)arm.com>
Date: Wed, 1 May 2024 15:33:10 +0100
Subject: [PATCH] mm: fix race between __split_huge_pmd_locked() and GUP-fast
__split_huge_pmd_locked() can be called for a present THP, devmap or
(non-present) migration entry. It calls pmdp_invalidate() unconditionally
on the pmdp and only determines if it is present or not based on the
returned old pmd. This is a problem for the migration entry case because
pmd_mkinvalid(), called by pmdp_invalidate() must only be called for a
present pmd.
On arm64 at least, pmd_mkinvalid() will mark the pmd such that any future
call to pmd_present() will return true. And therefore any lockless
pgtable walker could see the migration entry pmd in this state and start
interpretting the fields as if it were present, leading to BadThings (TM).
GUP-fast appears to be one such lockless pgtable walker.
x86 does not suffer the above problem, but instead pmd_mkinvalid() will
corrupt the offset field of the swap entry within the swap pte. See link
below for discussion of that problem.
Fix all of this by only calling pmdp_invalidate() for a present pmd. And
for good measure let's add a warning to all implementations of
pmdp_invalidate[_ad](). I've manually reviewed all other
pmdp_invalidate[_ad]() call sites and believe all others to be conformant.
This is a theoretical bug found during code review. I don't have any test
case to trigger it in practice.
Link: https://lkml.kernel.org/r/20240501143310.1381675-1-ryan.roberts@arm.com
Link: https://lore.kernel.org/all/0dd7827a-6334-439a-8fd0-43c98e6af22b@arm.com/
Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com>
Reviewed-by: Zi Yan <ziy(a)nvidia.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual(a)arm.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Andreas Larsson <andreas(a)gaisler.com>
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org>
Cc: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu>
Cc: Dave Hansen <dave.hansen(a)linux.intel.com>
Cc: "David S. Miller" <davem(a)davemloft.net>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Jonathan Corbet <corbet(a)lwn.net>
Cc: Mark Rutland <mark.rutland(a)arm.com>
Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com>
Cc: Nicholas Piggin <npiggin(a)gmail.com>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Sven Schnelle <svens(a)linux.ibm.com>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Will Deacon <will(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/Documentation/mm/arch_pgtable_helpers.rst b/Documentation/mm/arch_pgtable_helpers.rst
index 2466d3363af7..ad50ca6f495e 100644
--- a/Documentation/mm/arch_pgtable_helpers.rst
+++ b/Documentation/mm/arch_pgtable_helpers.rst
@@ -140,7 +140,8 @@ PMD Page Table Helpers
+---------------------------+--------------------------------------------------+
| pmd_swp_clear_soft_dirty | Clears a soft dirty swapped PMD |
+---------------------------+--------------------------------------------------+
-| pmd_mkinvalid | Invalidates a mapped PMD [1] |
+| pmd_mkinvalid | Invalidates a present PMD; do not call for |
+| | non-present PMD [1] |
+---------------------------+--------------------------------------------------+
| pmd_set_huge | Creates a PMD huge mapping |
+---------------------------+--------------------------------------------------+
@@ -196,7 +197,8 @@ PUD Page Table Helpers
+---------------------------+--------------------------------------------------+
| pud_mkdevmap | Creates a ZONE_DEVICE mapped PUD |
+---------------------------+--------------------------------------------------+
-| pud_mkinvalid | Invalidates a mapped PUD [1] |
+| pud_mkinvalid | Invalidates a present PUD; do not call for |
+| | non-present PUD [1] |
+---------------------------+--------------------------------------------------+
| pud_set_huge | Creates a PUD huge mapping |
+---------------------------+--------------------------------------------------+
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 83823db3488b..2975ea0841ba 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -170,6 +170,7 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
{
unsigned long old_pmd;
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return __pmd(old_pmd);
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2cb2a2e7b34b..558902edbfec 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1769,8 +1769,10 @@ static inline pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
static inline pmd_t pmdp_invalidate(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
{
- pmd_t pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
+ pmd_t pmd;
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
+ pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
return pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
}
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index 19642f7ffb52..8648a50afe88 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -249,6 +249,7 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
{
pmd_t old, entry;
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID);
old = pmdp_establish(vma, address, pmdp, entry);
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 94767c82fc0d..93e54ba91fbf 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -631,6 +631,8 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma,
pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
+
/*
* No flush is necessary. Once an invalid PTE is established, the PTE's
* access and dirty bits cannot be updated.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 08e4f3343bcd..ccdcff73284a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2430,32 +2430,11 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
return __split_huge_zero_page_pmd(vma, haddr, pmd);
}
- /*
- * Up to this point the pmd is present and huge and userland has the
- * whole access to the hugepage during the split (which happens in
- * place). If we overwrite the pmd with the not-huge version pointing
- * to the pte here (which of course we could if all CPUs were bug
- * free), userland could trigger a small page size TLB miss on the
- * small sized TLB while the hugepage TLB entry is still established in
- * the huge TLB. Some CPU doesn't like that.
- * See http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum
- * 383 on page 105. Intel should be safe but is also warns that it's
- * only safe if the permission and cache attributes of the two entries
- * loaded in the two TLB is identical (which should be the case here).
- * But it is generally safer to never allow small and huge TLB entries
- * for the same virtual address to be loaded simultaneously. So instead
- * of doing "pmd_populate(); flush_pmd_tlb_range();" we first mark the
- * current pmd notpresent (atomically because here the pmd_trans_huge
- * must remain set at all times on the pmd until the split is complete
- * for this pmd), then we flush the SMP TLB and finally we write the
- * non-huge version of the pmd entry with pmd_populate.
- */
- old_pmd = pmdp_invalidate(vma, haddr, pmd);
-
- pmd_migration = is_pmd_migration_entry(old_pmd);
+ pmd_migration = is_pmd_migration_entry(*pmd);
if (unlikely(pmd_migration)) {
swp_entry_t entry;
+ old_pmd = *pmd;
entry = pmd_to_swp_entry(old_pmd);
page = pfn_swap_entry_to_page(entry);
write = is_writable_migration_entry(entry);
@@ -2466,6 +2445,30 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
soft_dirty = pmd_swp_soft_dirty(old_pmd);
uffd_wp = pmd_swp_uffd_wp(old_pmd);
} else {
+ /*
+ * Up to this point the pmd is present and huge and userland has
+ * the whole access to the hugepage during the split (which
+ * happens in place). If we overwrite the pmd with the not-huge
+ * version pointing to the pte here (which of course we could if
+ * all CPUs were bug free), userland could trigger a small page
+ * size TLB miss on the small sized TLB while the hugepage TLB
+ * entry is still established in the huge TLB. Some CPU doesn't
+ * like that. See
+ * http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum
+ * 383 on page 105. Intel should be safe but is also warns that
+ * it's only safe if the permission and cache attributes of the
+ * two entries loaded in the two TLB is identical (which should
+ * be the case here). But it is generally safer to never allow
+ * small and huge TLB entries for the same virtual address to be
+ * loaded simultaneously. So instead of doing "pmd_populate();
+ * flush_pmd_tlb_range();" we first mark the current pmd
+ * notpresent (atomically because here the pmd_trans_huge must
+ * remain set at all times on the pmd until the split is
+ * complete for this pmd), then we flush the SMP TLB and finally
+ * we write the non-huge version of the pmd entry with
+ * pmd_populate.
+ */
+ old_pmd = pmdp_invalidate(vma, haddr, pmd);
page = pmd_page(old_pmd);
folio = page_folio(page);
if (pmd_dirty(old_pmd)) {
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 4fcd959dcc4d..a78a4adf711a 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -198,6 +198,7 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp));
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return old;
@@ -208,6 +209,7 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
+ VM_WARN_ON_ONCE(!pmd_present(*pmdp));
return pmdp_invalidate(vma, address, pmdp);
}
#endif