kernel.git/arch/riscv/kernel/process.c, branch linux-5.9.y

sched/idle: Fix arch_cpu_idle() vs tracing

2020-12-16T09:58:32Z

[ Upstream commit 58c644ba512cfbc2e39b758dd979edd1d6d00e27 ] We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Mark Rutland Tested-by: Mark Rutland Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org Signed-off-by: Sasha Levin

Merge tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2020-08-07T17:11:12Z

Pull RISC-V updates from Palmer Dabbelt: "We have a lot of new kernel features for this merge window: - ARCH_SUPPORTS_ATOMIC_RMW, to allow OSQ locks to be enabled - The ability to enable NO_HZ_FULL - Support for enabling kcov, kmemleak, stack protector, and VM debugging - JUMP_LABEL support There are also a handful of cleanups" * tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (24 commits) riscv: disable stack-protector for vDSO RISC-V: Fix build warning for smpboot.c riscv: fix build warning of mm/pageattr riscv: Fix build warning for mm/init RISC-V: Setup exception vector early riscv: Select ARCH_HAS_DEBUG_VM_PGTABLE riscv: Use generic pgprot_* macros from mm: pgtable: Make generic pgprot_* macros available for no-MMU riscv: Cleanup unnecessary define in asm-offset.c riscv: Add jump-label implementation riscv: Support R_RISCV_ADD64 and R_RISCV_SUB64 relocs Replace HTTP links with HTTPS ones: RISC-V riscv: Add STACKPROTECTOR supported riscv: Fix typo in asm/hwcap.h uapi header riscv: Add kmemleak support riscv: Allow building with kcov coverage riscv: Enable context tracking riscv: Support irq_work via self IPIs riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT riscv: Fixup lockdep_assert_held with wrong param cpu_running ...

riscv: Add STACKPROTECTOR supported

2020-07-30T18:37:39Z

The -fstack-protector & -fstack-protector-strong features are from gcc. The patch only add basic kernel support to stack-protector feature and some arch could have its own solution such as ARM64_PTR_AUTH. After enabling STACKPROTECTOR and STACKPROTECTOR_STRONG, the .text size is expanded from 0x7de066 to 0x81fb32 (only 5%) to add canary checking code. Signed-off-by: Guo Ren Reviewed-by: Kees Cook Signed-off-by: Palmer Dabbelt

arch: rename copy_thread_tls() back to copy_thread()

2020-07-04T21:41:37Z

Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls() back simply copy_thread(). It's a simpler name, and doesn't imply that only tls is copied here. This finishes an outstanding chunk of internal process creation work since we've added clone3(). Cc: linux-arch@vger.kernel.org Acked-by: Thomas Bogendoerfer A Acked-by: Stafford Horne Acked-by: Greentime Hu Acked-by: Geert Uytterhoeven A Reviewed-by: Kees Cook Signed-off-by: Christian Brauner

RISC-V: gp_in_global needs register keyword

2020-05-21T20:28:26Z

The Intel kernel build robot recently pointed out that I missed the register keyword on this one when I refactored the code to remove local register variables (which aren't supported by LLVM). GCC's manual indicates that global register variables must have the register keyword, As far as I can tell lacking the register keyword causes GCC to ignore the __asm__ and treat this as a regular variable, but I'm not sure how that didn't show up as some sort of failure. Fixes: 52e7c52d2ded ("RISC-V: Stop relying on GCC's register allocator's hueristics") Signed-off-by: Palmer Dabbelt

RISC-V: Stop relying on GCC's register allocator's hueristics

2020-03-03T18:28:13Z

GCC allows users to hint to the register allocation that a variable should be placed in a register by using a syntax along the lines of function(...) { register long in_REG __asm__("REG"); } We've abused this a bit throughout the RISC-V port to access fixed registers directly as C variables. In practice it's never going to blow up because GCC isn't going to allocate these registers, but it's not a well defined syntax so we really shouldn't be relying upon this. Luckily there is a very similar but well defined syntax that allows us to still access these registers directly as C variables, which is to simply declare the register variables globally. For fixed variables this doesn't change the ABI. LLVM disallows this ambiguous syntax, so this isn't just strictly a formatting change. Signed-off-by: Palmer Dabbelt

riscv: Implement copy_thread_tls

2020-01-07T12:31:23Z

This is required for clone3 which passes the TLS value through a struct rather than a register. Signed-off-by: Amanieu d'Antras Cc: linux-riscv@lists.infradead.org Cc: # 5.3.x Link: https://lore.kernel.org/r/20200102172413.654385-6-amanieu@gmail.com Signed-off-by: Christian Brauner

riscv: abstract out CSR names for supervisor vs machine mode

2019-11-05T17:20:42Z

Many of the privileged CSRs exist in a supervisor and machine version that are used very similarly. Provide versions of the CSR names and fields that map to either the S-mode or M-mode variant depending on a new CONFIG_RISCV_M_MODE kconfig symbol. Contains contributions from Damien Le Moal and Paul Walmsley . Signed-off-by: Christoph Hellwig Acked-by: Thomas Gleixner # for drivers/clocksource, drivers/irqchip [paul.walmsley@sifive.com: updated to apply] Signed-off-by: Paul Walmsley

riscv: add missing header file includes

2019-10-28T07:46:01Z

sparse identifies several missing prototypes caused by missing preprocessor include directives: arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static? arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static? arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static? arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static? arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static? arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static? arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static? arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static? arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static? Fix by including the appropriate header files in the appropriate source files. This patch should have no functional impact. Signed-off-by: Paul Walmsley Reviewed-by: Christoph Hellwig

riscv: Correct the initialized flow of FP register

2019-08-14T20:11:11Z

The following two reasons cause FP registers are sometimes not initialized before starting the user program. 1. Currently, the FP context is initialized in flush_thread() function and we expect these initial values to be restored to FP register when doing FP context switch. However, the FP context switch only occurs in switch_to function. Hence, if this process does not be scheduled out and scheduled in before entering the user space, the FP registers have no chance to initialize. 2. In flush_thread(), the state of reg->sstatus.FS inherits from the parent. Hence, the state of reg->sstatus.FS may be dirty. If this process is scheduled out during flush_thread() and initializing the FP register, the fstate_save() in switch_to will corrupt the FP context which has been initialized until flush_thread(). To solve the 1st case, the initialization of the FP register will be completed in start_thread(). It makes sure all FP registers are initialized before starting the user program. For the 2nd case, the state of reg->sstatus.FS in start_thread will be set to SR_FS_OFF to prevent this process from corrupting FP context in doing context save. The FP state is set to SR_FS_INITIAL in start_trhead(). Signed-off-by: Vincent Chen Reviewed-by: Anup Patel Reviewed-by: Christoph Hellwig Fixes: 7db91e57a0acd ("RISC-V: Task implementation") Cc: stable@vger.kernel.org [paul.walmsley@sifive.com: fixed brace alignment issue reported by checkpatch] Signed-off-by: Paul Walmsley