kernel/linux.git/Documentation, branch v6.1.66

smp,csd: Throw an error if a CSD lock is stuck for too long

2023-11-28T17:06:55+00:00

[ Upstream commit 94b3f0b5af2c7af69e3d6e0cdd9b0ea535f22186 ] The CSD lock seems to get stuck in 2 "modes". When it gets stuck temporarily, it usually gets released in a few seconds, and sometimes up to one or two minutes. If the CSD lock stays stuck for more than several minutes, it never seems to get unstuck, and gradually more and more things in the system end up also getting stuck. In the latter case, we should just give up, so the system can dump out a little more information about what went wrong, and, with panic_on_oops and a kdump kernel loaded, dump a whole bunch more information about what might have gone wrong. In addition, there is an smp.panic_on_ipistall kernel boot parameter that by default retains the old behavior, but when set enables the panic after the CSD lock has been stuck for more than the specified number of milliseconds, as in 300,000 for five minutes. [ paulmck: Apply Imran Khan feedback. ] [ paulmck: Apply Leonardo Bras feedback. ] Link: https://lore.kernel.org/lkml/bc7cc8b0-f587-4451-8bcd-0daae627bcc7@paulmck-laptop/ Signed-off-by: Rik van Riel Signed-off-by: Paul E. McKenney Reviewed-by: Imran Khan Reviewed-by: Leonardo Bras Cc: Peter Zijlstra Cc: Valentin Schneider Cc: Juergen Gross Cc: Jonathan Corbet Cc: Randy Dunlap Signed-off-by: Sasha Levin

x86/sev: Change snp_guest_issue_request()'s fw_err argument

2023-11-20T10:52:13+00:00

[ Upstream commit 0144e3b85d7b42e8a4cda991c0e81f131897457a ] The GHCB specification declares that the firmware error value for a guest request will be stored in the lower 32 bits of EXIT_INFO_2. The upper 32 bits are for the VMM's own error code. The fw_err argument to snp_guest_issue_request() is thus a misnomer, and callers will need access to all 64 bits. The type of unsigned long also causes problems, since sw_exit_info2 is u64 (unsigned long long) vs the argument's unsigned long*. Change this type for issuing the guest request. Pass the ioctl command struct's error field directly instead of in a local variable, since an incomplete guest request may not set the error code, and uninitialized stack memory would be written back to user space. The firmware might not even be called, so bookend the call with the no firmware call error and clear the error. Since the "fw_err" field is really exitinfo2 split into the upper bits' vmm error code and lower bits' firmware error code, convert the 64 bit value to a union. [ bp: - Massage commit message - adjust code - Fix a build issue as Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202303070609.vX6wp2Af-lkp@intel.com - print exitinfo2 in hex Tom: - Correct -EIO exit case. ] Signed-off-by: Dionna Glaze Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230214164638.1189804-5-dionnaglaze@google.com Link: https://lore.kernel.org/r/20230307192449.24732-12-bp@alien8.de Stable-dep-of: db10cb9b5746 ("virt: sevguest: Fix passing a stack buffer as a scatterlist target") Signed-off-by: Sasha Levin

crypto: ccp - Name -1 return value as SEV_RET_NO_FW_CALL

2023-11-20T10:52:13+00:00

[ Upstream commit efb339a83368ab25de1a18c0fdff85e01c13a1ea ] The PSP can return a "firmware error" code of -1 in circumstances where the PSP has not actually been called. To make this protocol unambiguous, name the value SEV_RET_NO_FW_CALL. [ bp: Massage a bit. ] Signed-off-by: Peter Gonda Signed-off-by: Dionna Glaze Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20221207010210.2563293-2-dionnaglaze@google.com Stable-dep-of: db10cb9b5746 ("virt: sevguest: Fix passing a stack buffer as a scatterlist target") Signed-off-by: Sasha Levin

dt-bindings: mfd: mt6397: Split out compatible for MediaTek MT6366 PMIC

2023-11-20T10:52:08+00:00

[ Upstream commit 61fdd1f1d2c183ec256527d16d75e75c3582af82 ] The MT6366 PMIC is mostly, but not fully, compatible with MT6358. It has a different set of regulators. Specifically, it lacks the camera related VCAM* LDOs and VLDO28, but has additional VM18, VMDDR, and VSRAM_CORE LDOs. The PMICs contain a chip ID register that can be used to detect which exact model is preset, so it is possible to share a common base compatible string. Add a separate compatible for the MT6366 PMIC, with a fallback to the MT6358 PMIC. Fixes: 49be16305587 ("dt-bindings: mfd: Add compatible for the MediaTek MT6366 PMIC") Signed-off-by: Chen-Yu Tsai Acked-by: Krzysztof Kozlowski Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20230928085537.3246669-2-wenst@chromium.org Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

dt-bindings: mfd: mt6397: Add binding for MT6357

2023-11-20T10:52:08+00:00

[ Upstream commit 118ee241c423636c03527eada8f672301514751e ] Add binding documentation for the MT6357 PMIC. Signed-off-by: Fabien Parent Signed-off-by: Alexandre Mergnat Acked-by: Rob Herring Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20221005-mt6357-support-v3-1-7e0bd7c315b2@baylibre.com Stable-dep-of: 61fdd1f1d2c1 ("dt-bindings: mfd: mt6397: Split out compatible for MediaTek MT6366 PMIC") Signed-off-by: Sasha Levin

dt-bindings: mmc: sdhci-msm: correct minimum number of clocks

2023-10-25T10:03:13+00:00

commit 1bbac8d6af085408885675c1e29b2581250be124 upstream. In the TXT binding before conversion, the "xo" clock was listed as optional. Conversion kept it optional in "clock-names", but not in "clocks". This fixes dbts_check warnings like: qcom-sdx65-mtp.dtb: mmc@8804000: clocks: [[13, 59], [13, 58]] is too short Cc: Fixes: a45537723f4b ("dt-bindings: mmc: sdhci-msm: Convert bindings to yaml") Signed-off-by: Krzysztof Kozlowski Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20230825135503.282135-1-krzysztof.kozlowski@linaro.org Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

tcp: enforce receive buffer memory limits by allowing the tcp window to shrink

2023-10-19T21:08:54+00:00

[ Upstream commit b650d953cd391595e536153ce30b4aab385643ac ] Under certain circumstances, the tcp receive buffer memory limit set by autotuning (sk_rcvbuf) is increased due to incoming data packets as a result of the window not closing when it should be. This can result in the receive buffer growing all the way up to tcp_rmem[2], even for tcp sessions with a low BDP. To reproduce: Connect a TCP session with the receiver doing nothing and the sender sending small packets (an infinite loop of socket send() with 4 bytes of payload with a sleep of 1 ms in between each send()). This will cause the tcp receive buffer to grow all the way up to tcp_rmem[2]. As a result, a host can have individual tcp sessions with receive buffers of size tcp_rmem[2], and the host itself can reach tcp_mem limits, causing the host to go into tcp memory pressure mode. The fundamental issue is the relationship between the granularity of the window scaling factor and the number of byte ACKed back to the sender. This problem has previously been identified in RFC 7323, appendix F [1]. The Linux kernel currently adheres to never shrinking the window. In addition to the overallocation of memory mentioned above, the current behavior is functionally incorrect, because once tcp_rmem[2] is reached when no remediations remain (i.e. tcp collapse fails to free up any more memory and there are no packets to prune from the out-of-order queue), the receiver will drop in-window packets resulting in retransmissions and an eventual timeout of the tcp session. A receive buffer full condition should instead result in a zero window and an indefinite wait. In practice, this problem is largely hidden for most flows. It is not applicable to mice flows. Elephant flows can send data fast enough to "overrun" the sk_rcvbuf limit (in a single ACK), triggering a zero window. But this problem does show up for other types of flows. Examples are websockets and other type of flows that send small amounts of data spaced apart slightly in time. In these cases, we directly encounter the problem described in [1]. RFC 7323, section 2.4 [2], says there are instances when a retracted window can be offered, and that TCP implementations MUST ensure that they handle a shrinking window, as specified in RFC 1122, section 4.2.2.16 [3]. All prior RFCs on the topic of tcp window management have made clear that sender must accept a shrunk window from the receiver, including RFC 793 [4] and RFC 1323 [5]. This patch implements the functionality to shrink the tcp window when necessary to keep the right edge within the memory limit by autotuning (sk_rcvbuf). This new functionality is enabled with the new sysctl: net.ipv4.tcp_shrink_window Additional information can be found at: https://blog.cloudflare.com/unbounded-memory-usage-by-tcp-for-receive-buffers-and-how-we-fixed-it/ [1] https://www.rfc-editor.org/rfc/rfc7323#appendix-F [2] https://www.rfc-editor.org/rfc/rfc7323#section-2.4 [3] https://www.rfc-editor.org/rfc/rfc1122#page-91 [4] https://www.rfc-editor.org/rfc/rfc793 [5] https://www.rfc-editor.org/rfc/rfc1323 Signed-off-by: Mike Freemon Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

dt-bindings: interrupt-controller: renesas,rzg2l-irqc: Update description for '#interrupt-cells' property

2023-10-19T21:08:50+00:00

commit cfa1f9db6d6088118ef311c0927c66072665b47e upstream. Update description for '#interrupt-cells' property to utilize the RZG2L_{NMI,IRQX} for the first cell defined in the include/dt-bindings/interrupt-controller/irqc-rzg2l.h file. Signed-off-by: Lad Prabhakar Reviewed-by: Geert Uytterhoeven Fixes: 96fed779d3d4cb3c ("dt-bindings: interrupt-controller: Add Renesas RZ/G2L Interrupt Controller") Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220722151155.21100-3-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

arm64: errata: Add Cortex-A520 speculative unprivileged load workaround

2023-10-10T20:00:39+00:00

commit 471470bc7052d28ce125901877dd10e4c048e513 upstream. Implement the workaround for ARM Cortex-A520 erratum 2966298. On an affected Cortex-A520 core, a speculatively executed unprivileged load might leak data from a privileged load via a cache side channel. The issue only exists for loads within a translation regime with the same translation (e.g. same ASID and VMID). Therefore, the issue only affects the return to EL0. The workaround is to execute a TLBI before returning to EL0 after all loads of privileged data. A non-shareable TLBI to any address is sufficient. The workaround isn't necessary if page table isolation (KPTI) is enabled, but for simplicity it will be. Page table isolation should normally be disabled for Cortex-A520 as it supports the CSV3 feature and the E0PD feature (used when KASLR is enabled). Cc: stable@vger.kernel.org Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20230921194156.1050055-2-robh@kernel.org Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

net: change accept_ra_min_rtr_lft to affect all RA lifetimes

2023-10-10T20:00:37+00:00

commit 5027d54a9c30bc7ec808360378e2b4753f053f25 upstream. accept_ra_min_rtr_lft only considered the lifetime of the default route and discarded entire RAs accordingly. This change renames accept_ra_min_rtr_lft to accept_ra_min_lft, and applies the value to individual RA sections; in particular, router lifetime, PIO preferred lifetime, and RIO lifetime. If any of those lifetimes are lower than the configured value, the specific RA section is ignored. In order for the sysctl to be useful to Android, it should really apply to all lifetimes in the RA, since that is what determines the minimum frequency at which RAs must be processed by the kernel. Android uses hardware offloads to drop RAs for a fraction of the minimum of all lifetimes present in the RA (some networks have very frequent RAs (5s) with high lifetimes (2h)). Despite this, we have encountered networks that set the router lifetime to 30s which results in very frequent CPU wakeups. Instead of disabling IPv6 (and dropping IPv6 ethertype in the WiFi firmware) entirely on such networks, it seems better to ignore the misconfigured routers while still processing RAs from other IPv6 routers on the same network (i.e. to support IoT applications). The previous implementation dropped the entire RA based on router lifetime. This turned out to be hard to expand to the other lifetimes present in the RA in a consistent manner; dropping the entire RA based on RIO/PIO lifetimes would essentially require parsing the whole thing twice. Fixes: 1671bcfd76fd ("net: add sysctl accept_ra_min_rtr_lft") Cc: Lorenzo Colitti Signed-off-by: Patrick Rohr Reviewed-by: Maciej Żenczykowski Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230726230701.919212-1-prohr@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman