kernel/git/stable/linux.git/arch/riscv, branch linux-5.5.y

riscv: uaccess should be used in nommu mode

2020-04-17T14:11:49+00:00

[ Upstream commit adccfb1a805ea84d2db38eb53032533279bdaa97 ] It might have the unaligned access exception when trying to exchange data with user space program. In this case, it failed in tty_ioctl(). Therefore we should enable uaccess.S for NOMMU mode since the generic code doesn't handle the unaligned access cases. 0x8013a212 : ld a5,460(s1) [ 0.115279] Oops - load address misaligned [#1] [ 0.115284] CPU: 0 PID: 29 Comm: sh Not tainted 5.4.0-rc5-00020-gb4c27160d562-dirty #36 [ 0.115294] epc: 000000008013a212 ra : 000000008013a212 sp : 000000008f48dd50 [ 0.115303] gp : 00000000801cac28 tp : 000000008fb80000 t0 : 00000000000000e8 [ 0.115312] t1 : 000000008f58f108 t2 : 0000000000000009 s0 : 000000008f48ddf0 [ 0.115321] s1 : 000000008f8c6220 a0 : 0000000000000001 a1 : 000000008f48dd28 [ 0.115330] a2 : 000000008fb80000 a3 : 00000000801a7398 a4 : 0000000000000000 [ 0.115339] a5 : 0000000000000000 a6 : 000000008f58f0c6 a7 : 000000000000001d [ 0.115348] s2 : 000000008f8c6308 s3 : 000000008f78b7c8 s4 : 000000008fb834c0 [ 0.115357] s5 : 0000000000005413 s6 : 0000000000000000 s7 : 000000008f58f2b0 [ 0.115366] s8 : 000000008f858008 s9 : 000000008f776818 s10: 000000008f776830 [ 0.115375] s11: 000000008fb840a8 t3 : 1999999999999999 t4 : 000000008f78704c [ 0.115384] t5 : 0000000000000005 t6 : 0000000000000002 [ 0.115391] status: 0000000200001880 badaddr: 000000008f8c63ec cause: 0000000000000004 [ 0.115401] ---[ end trace 00d490c6a8b6c9ac ]--- This failure could be fixed after this patch applied. [ 0.002282] Run /init as init process Initializing random number generator... [ 0.005573] random: dd: uninitialized urandom read (512 bytes read) done. Welcome to Buildroot buildroot login: root Password: Jan 1 00:00:00 login[62]: root login on 'ttySIF0' ~ # Signed-off-by: Greentime Hu Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

riscv: fix seccomp reject syscall code path

2020-03-25T07:26:58+00:00

[ Upstream commit af33d2433b03d63ed31fcfda842f46676a5e1afc ] If secure_computing() rejected a system call, we were previously setting the system call number to -1, to indicate to later code that the syscall failed. However, if something (e.g. a user notification) was sleeping, and received a signal, we may set a0 to -ERESTARTSYS and re-try the system call again. In this case, seccomp "denies" the syscall (because of the signal), and we would set a7 to -1, thus losing the value of the system call we want to restart. Instead, let's return -1 from do_syscall_trace_enter() to indicate that the syscall was rejected, so we don't clobber the value in case of -ERESTARTSYS or whatever. This commit fixes the user_notification_signal seccomp selftest on riscv to no longer hang. That test expects the system call to be re-issued after the signal, and it wasn't due to the above bug. Now that it is, everything works normally. Note that in the ptrace (tracer) case, the tracer can set the register values to whatever they want, so we still need to keep the code that handles out-of-bounds syscalls. However, we can drop the comment. We can also drop syscall_set_nr(), since it is no longer used anywhere, and the code that re-loads the value in a7 because of it. Reported in: https://lore.kernel.org/bpf/CAEn-LTp=ss0Dfv6J00=rCAy+N78U2AmhqJNjfqjr2FDpPYjxEQ@mail.gmail.com/ Reported-by: David Abdurachmanov Signed-off-by: Tycho Andersen Reviewed-by: Kees Cook Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

riscv: Fix range looking for kernel image memblock

2020-03-25T07:26:57+00:00

[ Upstream commit a160eed4b783d7b250a32f7e5787c9867abc5686 ] When looking for the memblock where the kernel lives, we should check that the memory range associated to the memblock entirely comprises the kernel image and not only intersects with it. Signed-off-by: Alexandre Ghiti Reviewed-by: Anup Patel Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

riscv: Force flat memory model with no-mmu

2020-03-25T07:26:57+00:00

[ Upstream commit aa2734202acc506d09c8e641db4da161f902df27 ] Compilation errors trigger if ARCH_SPARSEMEM_ENABLE is enabled for a nommu kernel. Since the sparsemem model does not make sense anyway for the nommu case, do not allow selecting this option to always use the flatmem model. Signed-off-by: Damien Le Moal Reviewed-by: Anup Patel Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

riscv: avoid the PIC offset of static percpu data in module beyond 2G limits

2020-03-25T07:26:57+00:00

[ Upstream commit 0cff8bff7af886af0923d5c91776cd51603e531f ] The compiler uses the PIC-relative method to access static variables instead of GOT when the code model is PIC. Therefore, the limitation of the access range from the instruction to the symbol address is +-2GB. Under this circumstance, the kernel cannot load a kernel module if this module has static per-CPU symbols declared by DEFINE_PER_CPU(). The reason is that kernel relocates the .data..percpu section of the kernel module to the end of kernel's .data..percpu. Hence, the distance between the per-CPU symbols and the instruction will exceed the 2GB limits. To solve this problem, the kernel should place the loaded module in the memory area [&_end-2G, VMALLOC_END]. Signed-off-by: Vincent Chen Suggested-by: Alexandre Ghiti Suggested-by: Anup Patel Tested-by: Alexandre Ghiti Tested-by: Carlos de Paula Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

riscv: set pmp configuration if kernel is running in M-mode

2020-03-21T07:15:41+00:00

[ Upstream commit c68a9032299e837b56d356de9250c93094f7e0e3 ] When the kernel is running in S-mode, the expectation is that the bootloader or SBI layer will configure the PMP to allow the kernel to access physical memory. But, when the kernel is running in M-mode and is started with the ELF "loader", there's probably no bootloader or SBI layer involved to configure the PMP. Thus, we need to configure the PMP ourselves to enable the kernel to access all regions. Signed-off-by: Greentime Hu Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

RISC-V: Don't enable all interrupts in trap_init()

2020-03-05T15:45:18+00:00

commit 6a1ce99dc4bde564e4a072936f9d41f4a439140e upstream. Historically, we have been enabling all interrupts for each HART in trap_init(). Ideally, we should only enable M-mode interrupts for M-mode kernel and S-mode interrupts for S-mode kernel in trap_init(). Currently, we get suprious S-mode interrupts on Kendryte K210 board running M-mode NO-MMU kernel because we are enabling all interrupts in trap_init(). To fix this, we only enable software and external interrupt in trap_init(). In future, trap_init() will only enable software interrupt and PLIC driver will enable external interrupt using CPU notifiers. Fixes: a4c3733d32a7 ("riscv: abstract out CSR names for supervisor vs machine mode") Signed-off-by: Anup Patel Reviewed-by: Atish Patra Tested-by: Palmer Dabbelt [QMEU virt machine with SMP] [Palmer: Move the Fixes up to a newer commit] Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

riscv, bpf: Fix broken BPF tail calls

2020-02-11T12:36:58+00:00

commit f1003b787c00fbaa4b11619c6b23a885bfce8f07 upstream. The BPF JIT incorrectly clobbered the a0 register, and did not flag usage of s5 register when BPF stack was being used. Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191216091343.23260-2-bjorn.topel@gmail.com Signed-off-by: Greg Kroah-Hartman

riscv: Less inefficient gcc tishift helpers (and export their symbols)

2020-01-19T03:13:41+00:00

The existing __lshrti3 was really inefficient, and the other two helpers are also needed to compile some modules. Add the missing versions, and export all of the symbols like arm64 already does. This code is based on the assembly generated by libgcc builds. This fixes a build break triggered by ubsan: riscv64-unknown-linux-gnu-ld: lib/ubsan.o: in function `.L2': ubsan.c:(.text.unlikely+0x38): undefined reference to `__ashlti3' riscv64-unknown-linux-gnu-ld: ubsan.c:(.text.unlikely+0x42): undefined reference to `__ashrti3' Signed-off-by: Olof Johansson [paul.walmsley@sifive.com: use SYM_FUNC_{START,END} instead of ENTRY/ENDPROC; note libgcc origin] Signed-off-by: Paul Walmsley

riscv: delete temporary files

2020-01-18T21:22:13+00:00

Temporary files used in the VDSO build process linger on even after make mrproper: vdso-dummy.o.tmp, vdso.so.dbg.tmp. Delete them once they're no longer needed. Signed-off-by: Ilie Halip Signed-off-by: Paul Walmsley