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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/arm/kernel/entry-header.S | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'arch/arm/kernel/entry-header.S')
-rw-r--r-- | arch/arm/kernel/entry-header.S | 467 |
1 files changed, 467 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S new file mode 100644 index 000000000..99411fa91 --- /dev/null +++ b/arch/arm/kernel/entry-header.S @@ -0,0 +1,467 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/init.h> +#include <linux/linkage.h> + +#include <asm/assembler.h> +#include <asm/asm-offsets.h> +#include <asm/errno.h> +#include <asm/thread_info.h> +#include <asm/uaccess-asm.h> +#include <asm/v7m.h> + +@ Bad Abort numbers +@ ----------------- +@ +#define BAD_PREFETCH 0 +#define BAD_DATA 1 +#define BAD_ADDREXCPTN 2 +#define BAD_IRQ 3 +#define BAD_UNDEFINSTR 4 + +@ +@ Most of the stack format comes from struct pt_regs, but with +@ the addition of 8 bytes for storing syscall args 5 and 6. +@ This _must_ remain a multiple of 8 for EABI. +@ +#define S_OFF 8 + +/* + * The SWI code relies on the fact that R0 is at the bottom of the stack + * (due to slow/fast restore user regs). + */ +#if S_R0 != 0 +#error "Please fix" +#endif + + .macro zero_fp +#ifdef CONFIG_FRAME_POINTER + mov fp, #0 +#endif + .endm + +#ifdef CONFIG_ALIGNMENT_TRAP +#define ATRAP(x...) x +#else +#define ATRAP(x...) +#endif + + .macro alignment_trap, rtmp1, rtmp2, label +#ifdef CONFIG_ALIGNMENT_TRAP + mrc p15, 0, \rtmp2, c1, c0, 0 + ldr_va \rtmp1, \label + teq \rtmp1, \rtmp2 + mcrne p15, 0, \rtmp1, c1, c0, 0 +#endif + .endm + +#ifdef CONFIG_CPU_V7M +/* + * ARMv7-M exception entry/exit macros. + * + * xPSR, ReturnAddress(), LR (R14), R12, R3, R2, R1, and R0 are + * automatically saved on the current stack (32 words) before + * switching to the exception stack (SP_main). + * + * If exception is taken while in user mode, SP_main is + * empty. Otherwise, SP_main is aligned to 64 bit automatically + * (CCR.STKALIGN set). + * + * Linux assumes that the interrupts are disabled when entering an + * exception handler and it may BUG if this is not the case. Interrupts + * are disabled during entry and reenabled in the exit macro. + * + * v7m_exception_slow_exit is used when returning from SVC or PendSV. + * When returning to kernel mode, we don't return from exception. + */ + .macro v7m_exception_entry + @ determine the location of the registers saved by the core during + @ exception entry. Depending on the mode the cpu was in when the + @ exception happend that is either on the main or the process stack. + @ Bit 2 of EXC_RETURN stored in the lr register specifies which stack + @ was used. + tst lr, #EXC_RET_STACK_MASK + mrsne r12, psp + moveq r12, sp + + @ we cannot rely on r0-r3 and r12 matching the value saved in the + @ exception frame because of tail-chaining. So these have to be + @ reloaded. + ldmia r12!, {r0-r3} + + @ Linux expects to have irqs off. Do it here before taking stack space + cpsid i + + sub sp, #PT_REGS_SIZE-S_IP + stmdb sp!, {r0-r11} + + @ load saved r12, lr, return address and xPSR. + @ r0-r7 are used for signals and never touched from now on. Clobbering + @ r8-r12 is OK. + mov r9, r12 + ldmia r9!, {r8, r10-r12} + + @ calculate the original stack pointer value. + @ r9 currently points to the memory location just above the auto saved + @ xPSR. + @ The cpu might automatically 8-byte align the stack. Bit 9 + @ of the saved xPSR specifies if stack aligning took place. In this case + @ another 32-bit value is included in the stack. + + tst r12, V7M_xPSR_FRAMEPTRALIGN + addne r9, r9, #4 + + @ store saved r12 using str to have a register to hold the base for stm + str r8, [sp, #S_IP] + add r8, sp, #S_SP + @ store r13-r15, xPSR + stmia r8!, {r9-r12} + @ store old_r0 + str r0, [r8] + .endm + + /* + * PENDSV and SVCALL are configured to have the same exception + * priorities. As a kernel thread runs at SVCALL execution priority it + * can never be preempted and so we will never have to return to a + * kernel thread here. + */ + .macro v7m_exception_slow_exit ret_r0 + cpsid i + ldr lr, =exc_ret + ldr lr, [lr] + + @ read original r12, sp, lr, pc and xPSR + add r12, sp, #S_IP + ldmia r12, {r1-r5} + + @ an exception frame is always 8-byte aligned. To tell the hardware if + @ the sp to be restored is aligned or not set bit 9 of the saved xPSR + @ accordingly. + tst r2, #4 + subne r2, r2, #4 + orrne r5, V7M_xPSR_FRAMEPTRALIGN + biceq r5, V7M_xPSR_FRAMEPTRALIGN + + @ ensure bit 0 is cleared in the PC, otherwise behaviour is + @ unpredictable + bic r4, #1 + + @ write basic exception frame + stmdb r2!, {r1, r3-r5} + ldmia sp, {r1, r3-r5} + .if \ret_r0 + stmdb r2!, {r0, r3-r5} + .else + stmdb r2!, {r1, r3-r5} + .endif + + @ restore process sp + msr psp, r2 + + @ restore original r4-r11 + ldmia sp!, {r0-r11} + + @ restore main sp + add sp, sp, #PT_REGS_SIZE-S_IP + + cpsie i + bx lr + .endm +#endif /* CONFIG_CPU_V7M */ + + @ + @ Store/load the USER SP and LR registers by switching to the SYS + @ mode. Useful in Thumb-2 mode where "stm/ldm rd, {sp, lr}^" is not + @ available. Should only be called from SVC mode + @ + .macro store_user_sp_lr, rd, rtemp, offset = 0 + mrs \rtemp, cpsr + eor \rtemp, \rtemp, #(SVC_MODE ^ SYSTEM_MODE) + msr cpsr_c, \rtemp @ switch to the SYS mode + + str sp, [\rd, #\offset] @ save sp_usr + str lr, [\rd, #\offset + 4] @ save lr_usr + + eor \rtemp, \rtemp, #(SVC_MODE ^ SYSTEM_MODE) + msr cpsr_c, \rtemp @ switch back to the SVC mode + .endm + + .macro load_user_sp_lr, rd, rtemp, offset = 0 + mrs \rtemp, cpsr + eor \rtemp, \rtemp, #(SVC_MODE ^ SYSTEM_MODE) + msr cpsr_c, \rtemp @ switch to the SYS mode + + ldr sp, [\rd, #\offset] @ load sp_usr + ldr lr, [\rd, #\offset + 4] @ load lr_usr + + eor \rtemp, \rtemp, #(SVC_MODE ^ SYSTEM_MODE) + msr cpsr_c, \rtemp @ switch back to the SVC mode + .endm + + + .macro svc_exit, rpsr, irq = 0 + .if \irq != 0 + @ IRQs already off +#ifdef CONFIG_TRACE_IRQFLAGS + @ The parent context IRQs must have been enabled to get here in + @ the first place, so there's no point checking the PSR I bit. + bl trace_hardirqs_on +#endif + .else + @ IRQs off again before pulling preserved data off the stack + disable_irq_notrace +#ifdef CONFIG_TRACE_IRQFLAGS + tst \rpsr, #PSR_I_BIT + bleq trace_hardirqs_on + tst \rpsr, #PSR_I_BIT + blne trace_hardirqs_off +#endif + .endif + uaccess_exit tsk, r0, r1 + +#ifndef CONFIG_THUMB2_KERNEL + @ ARM mode SVC restore + msr spsr_cxsf, \rpsr +#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K) + @ We must avoid clrex due to Cortex-A15 erratum #830321 + sub r0, sp, #4 @ uninhabited address + strex r1, r2, [r0] @ clear the exclusive monitor +#endif + ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr +#else + @ Thumb mode SVC restore + ldr lr, [sp, #S_SP] @ top of the stack + ldrd r0, r1, [sp, #S_LR] @ calling lr and pc + + @ We must avoid clrex due to Cortex-A15 erratum #830321 + strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor + + stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context + ldmia sp, {r0 - r12} + mov sp, lr + ldr lr, [sp], #4 + rfeia sp! +#endif + .endm + + @ + @ svc_exit_via_fiq - like svc_exit but switches to FIQ mode before exit + @ + @ This macro acts in a similar manner to svc_exit but switches to FIQ + @ mode to restore the final part of the register state. + @ + @ We cannot use the normal svc_exit procedure because that would + @ clobber spsr_svc (FIQ could be delivered during the first few + @ instructions of vector_swi meaning its contents have not been + @ saved anywhere). + @ + @ Note that, unlike svc_exit, this macro also does not allow a caller + @ supplied rpsr. This is because the FIQ exceptions are not re-entrant + @ and the handlers cannot call into the scheduler (meaning the value + @ on the stack remains correct). + @ + .macro svc_exit_via_fiq + uaccess_exit tsk, r0, r1 +#ifndef CONFIG_THUMB2_KERNEL + @ ARM mode restore + mov r0, sp + ldmib r0, {r1 - r14} @ abort is deadly from here onward (it will + @ clobber state restored below) + msr cpsr_c, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT + add r8, r0, #S_PC + ldr r9, [r0, #S_PSR] + msr spsr_cxsf, r9 + ldr r0, [r0, #S_R0] + ldmia r8, {pc}^ +#else + @ Thumb mode restore + add r0, sp, #S_R2 + ldr lr, [sp, #S_LR] + ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will + @ clobber state restored below) + ldmia r0, {r2 - r12} + mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT + msr cpsr_c, r1 + sub r0, #S_R2 + add r8, r0, #S_PC + ldmia r0, {r0 - r1} + rfeia r8 +#endif + .endm + + + .macro restore_user_regs, fast = 0, offset = 0 +#if defined(CONFIG_CPU_32v6K) && \ + (!defined(CONFIG_CPU_V6) || defined(CONFIG_SMP)) +#ifdef CONFIG_CPU_V6 +ALT_SMP(nop) +ALT_UP_B(.L1_\@) +#endif + @ The TLS register update is deferred until return to user space so we + @ can use it for other things while running in the kernel + mrc p15, 0, r1, c13, c0, 3 @ get current_thread_info pointer + ldr r1, [r1, #TI_TP_VALUE] + mcr p15, 0, r1, c13, c0, 3 @ set TLS register +.L1_\@: +#endif + + uaccess_enable r1, isb=0 +#ifndef CONFIG_THUMB2_KERNEL + @ ARM mode restore + mov r2, sp + ldr r1, [r2, #\offset + S_PSR] @ get calling cpsr + ldr lr, [r2, #\offset + S_PC]! @ get pc + tst r1, #PSR_I_BIT | 0x0f + bne 1f + msr spsr_cxsf, r1 @ save in spsr_svc +#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K) + @ We must avoid clrex due to Cortex-A15 erratum #830321 + strex r1, r2, [r2] @ clear the exclusive monitor +#endif + .if \fast + ldmdb r2, {r1 - lr}^ @ get calling r1 - lr + .else + ldmdb r2, {r0 - lr}^ @ get calling r0 - lr + .endif + mov r0, r0 @ ARMv5T and earlier require a nop + @ after ldm {}^ + add sp, sp, #\offset + PT_REGS_SIZE + movs pc, lr @ return & move spsr_svc into cpsr +1: bug "Returning to usermode but unexpected PSR bits set?", \@ +#elif defined(CONFIG_CPU_V7M) + @ V7M restore. + @ Note that we don't need to do clrex here as clearing the local + @ monitor is part of the exception entry and exit sequence. + .if \offset + add sp, #\offset + .endif + v7m_exception_slow_exit ret_r0 = \fast +#else + @ Thumb mode restore + mov r2, sp + load_user_sp_lr r2, r3, \offset + S_SP @ calling sp, lr + ldr r1, [sp, #\offset + S_PSR] @ get calling cpsr + ldr lr, [sp, #\offset + S_PC] @ get pc + add sp, sp, #\offset + S_SP + tst r1, #PSR_I_BIT | 0x0f + bne 1f + msr spsr_cxsf, r1 @ save in spsr_svc + + @ We must avoid clrex due to Cortex-A15 erratum #830321 + strex r1, r2, [sp] @ clear the exclusive monitor + + .if \fast + ldmdb sp, {r1 - r12} @ get calling r1 - r12 + .else + ldmdb sp, {r0 - r12} @ get calling r0 - r12 + .endif + add sp, sp, #PT_REGS_SIZE - S_SP + movs pc, lr @ return & move spsr_svc into cpsr +1: bug "Returning to usermode but unexpected PSR bits set?", \@ +#endif /* !CONFIG_THUMB2_KERNEL */ + .endm + +/* + * Context tracking subsystem. Used to instrument transitions + * between user and kernel mode. + */ + .macro ct_user_exit, save = 1 +#ifdef CONFIG_CONTEXT_TRACKING_USER + .if \save + stmdb sp!, {r0-r3, ip, lr} + bl user_exit_callable + ldmia sp!, {r0-r3, ip, lr} + .else + bl user_exit_callable + .endif +#endif + .endm + + .macro ct_user_enter, save = 1 +#ifdef CONFIG_CONTEXT_TRACKING_USER + .if \save + stmdb sp!, {r0-r3, ip, lr} + bl user_enter_callable + ldmia sp!, {r0-r3, ip, lr} + .else + bl user_enter_callable + .endif +#endif + .endm + + .macro invoke_syscall, table, nr, tmp, ret, reload=0 +#ifdef CONFIG_CPU_SPECTRE + mov \tmp, \nr + cmp \tmp, #NR_syscalls @ check upper syscall limit + movcs \tmp, #0 + csdb + badr lr, \ret @ return address + .if \reload + add r1, sp, #S_R0 + S_OFF @ pointer to regs + ldmiacc r1, {r0 - r6} @ reload r0-r6 + stmiacc sp, {r4, r5} @ update stack arguments + .endif + ldrcc pc, [\table, \tmp, lsl #2] @ call sys_* routine +#else + cmp \nr, #NR_syscalls @ check upper syscall limit + badr lr, \ret @ return address + .if \reload + add r1, sp, #S_R0 + S_OFF @ pointer to regs + ldmiacc r1, {r0 - r6} @ reload r0-r6 + stmiacc sp, {r4, r5} @ update stack arguments + .endif + ldrcc pc, [\table, \nr, lsl #2] @ call sys_* routine +#endif + .endm + +/* + * These are the registers used in the syscall handler, and allow us to + * have in theory up to 7 arguments to a function - r0 to r6. + * + * r7 is reserved for the system call number for thumb mode. + * + * Note that tbl == why is intentional. + * + * We must set at least "tsk" and "why" when calling ret_with_reschedule. + */ +scno .req r7 @ syscall number +tbl .req r8 @ syscall table pointer +why .req r8 @ Linux syscall (!= 0) +tsk .req r9 @ current thread_info + + .macro do_overflow_check, frame_size:req +#ifdef CONFIG_VMAP_STACK + @ + @ Test whether the SP has overflowed. Task and IRQ stacks are aligned + @ so that SP & BIT(THREAD_SIZE_ORDER + PAGE_SHIFT) should always be + @ zero. + @ +ARM( tst sp, #1 << (THREAD_SIZE_ORDER + PAGE_SHIFT) ) +THUMB( tst r1, #1 << (THREAD_SIZE_ORDER + PAGE_SHIFT) ) +THUMB( it ne ) + bne .Lstack_overflow_check\@ + + .pushsection .text +.Lstack_overflow_check\@: + @ + @ The stack pointer is not pointing to a valid vmap'ed stack, but it + @ may be pointing into the linear map instead, which may happen if we + @ are already running from the overflow stack. We cannot detect overflow + @ in such cases so just carry on. + @ + str ip, [r0, #12] @ Stash IP on the mode stack + ldr_va ip, high_memory @ Start of VMALLOC space +ARM( cmp sp, ip ) @ SP in vmalloc space? +THUMB( cmp r1, ip ) +THUMB( itt lo ) + ldrlo ip, [r0, #12] @ Restore IP + blo .Lout\@ @ Carry on + +THUMB( sub r1, sp, r1 ) @ Restore original R1 +THUMB( sub sp, r1 ) @ Restore original SP + add sp, sp, #\frame_size @ Undo svc_entry's SP change + b __bad_stack @ Handle VMAP stack overflow + .popsection +.Lout\@: +#endif + .endm |