0x7d and 0x7e bytes are meant to be escaped in the data portion of
frames, but this didn't occur since next_chunk_len() had an off-by-one
error. That also resulted in the final byte of a payload being written
as a separate tty write op.
The chunk prior to an escaped byte would be one byte short, and the
next call would never test the txpos+1 case, which is where the escaped
byte was located. That meant it never hit the escaping case in
mctp_serial_tx_work().
Example Input: 01 00 08 c8 7e 80 02
Previous incorrect chunks from next_chunk_len():
01 00 08
c8 7e 80
02
With this fix:
01 00 08 c8
7e
80 02
Cc: stable(a)vger.kernel.org
Fixes: a0c2ccd9b5ad ("mctp: Add MCTP-over-serial transport binding")
Signed-off-by: Matt Johnston <matt(a)codeconstruct.com.au>
---
drivers/net/mctp/mctp-serial.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c
index 7a40d07ff77b..f39bbe255497 100644
--- a/drivers/net/mctp/mctp-serial.c
+++ b/drivers/net/mctp/mctp-serial.c
@@ -91,8 +91,8 @@ static int next_chunk_len(struct mctp_serial *dev)
* will be those non-escaped bytes, and does not include the escaped
* byte.
*/
- for (i = 1; i + dev->txpos + 1 < dev->txlen; i++) {
- if (needs_escape(dev->txbuf[dev->txpos + i + 1]))
+ for (i = 1; i + dev->txpos < dev->txlen; i++) {
+ if (needs_escape(dev->txbuf[dev->txpos + i]))
break;
}
This fix addresses STAR 9001285599, which only affects dwc3 core version
320a. The timer value for PM_LC_TIMER in 320a for the Link ECN changes
is incorrect. If the PM TIMER ECN is enabled via GUCTL2[19], the link
compliance test (TD7.21) may fail. If the ECN is not enabled
(GUCTL2[19] = 0), the controller will use the old timer value (5us),
which is still acceptable for the link compliance test. Therefore, clear
GUCTL2[19] to pass the USB link compliance test: TD 7.21.
Cc: stable(a)vger.kernel.org
Signed-off-by: Faisal Hassan <quic_faisalh(a)quicinc.com>
---
drivers/usb/dwc3/core.c | 15 +++++++++++++++
drivers/usb/dwc3/core.h | 2 ++
2 files changed, 17 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 734de2a8bd21..d0bd3a0e1f9c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1378,6 +1378,21 @@ static int dwc3_core_init(struct dwc3 *dwc)
dwc3_writel(dwc->regs, DWC3_GUCTL2, reg);
}
+ /*
+ * STAR 9001285599: This issue affects dwc3 core version 3.20a
+ * only. If the PM TIMER ECM is enabled through GUCTL2[19], the
+ * link compliance test (TD7.21) may fail. If the ECN is not
+ * enabled (GUCTL2[19] = 0), the controller will use the old timer
+ * value (5us), which is still acceptable for the link compliance
+ * test. Therefore, do not enable PM TIMER ECM in 3.20a by
+ * setting GUCTL2[19] by default; instead, use GUCTL2[19] = 0.
+ */
+ if (DWC3_VER_IS(DWC3, 320A)) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUCTL2);
+ reg &= ~DWC3_GUCTL2_LC_TIMER;
+ dwc3_writel(dwc->regs, DWC3_GUCTL2, reg);
+ }
+
/*
* When configured in HOST mode, after issuing U3/L2 exit controller
* fails to send proper CRC checksum in CRC5 feild. Because of this
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 1e561fd8b86e..c71240e8f7c7 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -421,6 +421,7 @@
/* Global User Control Register 2 */
#define DWC3_GUCTL2_RST_ACTBITLATER BIT(14)
+#define DWC3_GUCTL2_LC_TIMER BIT(19)
/* Global User Control Register 3 */
#define DWC3_GUCTL3_SPLITDISABLE BIT(14)
@@ -1269,6 +1270,7 @@ struct dwc3 {
#define DWC3_REVISION_290A 0x5533290a
#define DWC3_REVISION_300A 0x5533300a
#define DWC3_REVISION_310A 0x5533310a
+#define DWC3_REVISION_320A 0x5533320a
#define DWC3_REVISION_330A 0x5533330a
#define DWC31_REVISION_ANY 0x0
--
2.17.1
When operating in High-Speed, it is observed that DSTS[USBLNKST] doesn't
update link state immediately after receiving the wakeup interrupt. Since
wakeup event handler calls the resume callbacks, there is a chance that
function drivers can perform an ep queue, which in turn tries to perform
remote wakeup from send_gadget_ep_cmd(STARTXFER). This happens because
DSTS[[21:18] wasn't updated to U0 yet, it's observed that the latency of
DSTS can be in order of milli-seconds. Hence avoid calling gadget_wakeup
during startxfer to prevent unnecessarily issuing remote wakeup to host.
Fixes: c36d8e947a56 ("usb: dwc3: gadget: put link to U0 before Start Transfer")
Cc: <stable(a)vger.kernel.org>
Suggested-by: Thinh Nguyen <Thinh.Nguyen(a)synopsys.com>
Signed-off-by: Prashanth K <quic_prashk(a)quicinc.com>
---
v5: Further rewording of the comment in function.
v4: Rewording the comment in function definition.
v3: Added notes on top the function definition.
v2: Refactored the patch as suggested in v1 discussion.
drivers/usb/dwc3/gadget.c | 41 ++++++++++++++++-----------------------
1 file changed, 17 insertions(+), 24 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 89fc690fdf34..291bc549935b 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -287,6 +287,23 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async);
*
* Caller should handle locking. This function will issue @cmd with given
* @params to @dep and wait for its completion.
+ *
+ * According to the programming guide, if the link state is in L1/L2/U3,
+ * then sending the Start Transfer command may not complete. The
+ * programming guide suggested to bring the link state back to ON/U0 by
+ * performing remote wakeup prior to sending the command. However, don't
+ * initiate remote wakeup when the user/function does not send wakeup
+ * request via wakeup ops. Send the command when it's allowed.
+ *
+ * Notes:
+ * For L1 link state, issuing a command requires the clearing of
+ * GUSB2PHYCFG.SUSPENDUSB2, which turns on the signal required to complete
+ * the given command (usually within 50us). This should happen within the
+ * command timeout set by driver. No additional step is needed.
+ *
+ * For L2 or U3 link state, the gadget is in USB suspend. Care should be
+ * taken when sending Start Transfer command to ensure that it's done after
+ * USB resume.
*/
int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd,
struct dwc3_gadget_ep_cmd_params *params)
@@ -327,30 +344,6 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd,
dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
}
- if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
- int link_state;
-
- /*
- * Initiate remote wakeup if the link state is in U3 when
- * operating in SS/SSP or L1/L2 when operating in HS/FS. If the
- * link state is in U1/U2, no remote wakeup is needed. The Start
- * Transfer command will initiate the link recovery.
- */
- link_state = dwc3_gadget_get_link_state(dwc);
- switch (link_state) {
- case DWC3_LINK_STATE_U2:
- if (dwc->gadget->speed >= USB_SPEED_SUPER)
- break;
-
- fallthrough;
- case DWC3_LINK_STATE_U3:
- ret = __dwc3_gadget_wakeup(dwc, false);
- dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
- ret);
- break;
- }
- }
-
/*
* For some commands such as Update Transfer command, DEPCMDPARn
* registers are reserved. Since the driver often sends Update Transfer
--
2.25.1
__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.
Cc: stable(a)vger.kernel.org
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>
---
Right v3; this goes back to the original approach in v1 to fix core-mm rather
than push the fix into arm64, since we discovered that x86 can't handle
pmd_mkinvalid() being called for non-present pmds either.
I'm pulling in more arch maintainers because this version adds some warnings in
arch code to help spot incorrect usage.
Although Catalin had already accepted v2 (fixing arm64) [2] into for-next/fixes,
he's agreed to either remove or revert it.
Changes since v1 [1]
====================
- Improve pmdp_mkinvalid() docs to make it clear it can only be called for
present pmd (per JohnH, Zi Yan)
- Added warnings to arch overrides of pmdp_invalidate[_ad]() (per Zi Yan)
- Moved comment next to new location of pmpd_invalidate() (per Zi Yan)
[1] https://lore.kernel.org/linux-mm/20240425170704.3379492-1-ryan.roberts@arm.…
[2] https://lore.kernel.org/all/20240430133138.732088-1-ryan.roberts@arm.com/
Thanks,
Ryan
Documentation/mm/arch_pgtable_helpers.rst | 6 ++-
arch/powerpc/mm/book3s64/pgtable.c | 1 +
arch/s390/include/asm/pgtable.h | 4 +-
arch/sparc/mm/tlb.c | 1 +
arch/x86/mm/pgtable.c | 2 +
mm/huge_memory.c | 49 ++++++++++++-----------
mm/pgtable-generic.c | 2 +
7 files changed, 39 insertions(+), 26 deletions(-)
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 60950e7a25f5..480bea44559d 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1768,8 +1768,10 @@ 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 b44d79d778c7..ef69127d7e5e 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 d007591b8059..103cbccf1d7d 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 89f58c7603b2..dd1fc105f70b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2493,32 +2493,11 @@ 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);
@@ -2529,6 +2508,30 @@ 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
--
2.25.1