linux.git/arch/riscv/kernel/process.c, branch v5.9 Linux kernel source tree Merge tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux 2020-08-07T17:11:12+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-08-07T17:11:12+00:00 dbf83817315d9ce93b3e5b1c83a167f537245bd8 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 <linux/pgtable.h> 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 ... 
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 <linux/pgtable.h>
  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 2020-07-30T18:37:39+00:00 Guo Ren guoren@linux.alibaba.com 2020-07-10T16:19:57+00:00 f2c9699f65557a31fed4ddb9e5b4d9489b1bf32f 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 <guoren@linux.alibaba.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
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 <guoren@linux.alibaba.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
arch: rename copy_thread_tls() back to copy_thread() 2020-07-04T21:41:37+00:00 Christian Brauner christian.brauner@ubuntu.com 2020-06-11T09:04:15+00:00 714acdbd1c94e7e3ab90f6b6938f1ccb27b662f0 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 <tsbogend@alpha.franken.de>A Acked-by: Stafford Horne <shorne@gmail.com> Acked-by: Greentime Hu <green.hu@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>A Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> 
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 <tsbogend@alpha.franken.de>A
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>A
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
RISC-V: gp_in_global needs register keyword 2020-05-21T20:28:26+00:00 Palmer Dabbelt palmerdabbelt@google.com 2020-05-21T20:28:26+00:00 8356c379cfba8b1b90b0a2423f6afbbe2cdc5d91 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 <palmerdabbelt@google.com> 
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 <palmerdabbelt@google.com>
RISC-V: Stop relying on GCC's register allocator's hueristics 2020-03-03T18:28:13+00:00 Palmer Dabbelt palmerdabbelt@google.com 2020-02-27T19:07:28+00:00 52e7c52d2ded5908e6a4f8a7248e5fa6e0d6809a 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 <palmerdabbelt@google.com> 
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 <palmerdabbelt@google.com>
riscv: Implement copy_thread_tls 2020-01-07T12:31:23+00:00 Amanieu d'Antras amanieu@gmail.com 2020-01-02T17:24:11+00:00 20bda4ed62f507ed72e30e817b43c65fdba60be7 This is required for clone3 which passes the TLS value through a struct rather than a register. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Cc: linux-riscv@lists.infradead.org Cc: <stable@vger.kernel.org> # 5.3.x Link: https://lore.kernel.org/r/20200102172413.654385-6-amanieu@gmail.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> 
This is required for clone3 which passes the TLS value through a
struct rather than a register.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-riscv@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200102172413.654385-6-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
riscv: abstract out CSR names for supervisor vs machine mode 2019-11-05T17:20:42+00:00 Christoph Hellwig hch@lst.de 2019-10-28T12:10:32+00:00 a4c3733d32a72f11dee86d0731d7565aa6ebe22d 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 <Damien.LeMoal@wdc.com> and Paul Walmsley <paul.walmsley@sifive.com>. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip [paul.walmsley@sifive.com: updated to apply] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> 
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 <Damien.LeMoal@wdc.com>
and Paul Walmsley <paul.walmsley@sifive.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip
[paul.walmsley@sifive.com: updated to apply]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
 riscv: add missing header file includes 2019-10-28T07:46:01+00:00 Paul Walmsley paul.walmsley@sifive.com 2019-10-17T22:21:28+00:00 5ed881bc3afc40d7a23c2211ead1aeb4980dda20 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 <paul.walmsley@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> 
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 <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
riscv: Correct the initialized flow of FP register 2019-08-14T20:11:11+00:00 Vincent Chen vincent.chen@sifive.com 2019-08-14T08:23:52+00:00 8ac71d7e46b94a4fc8ffc6f1c88004cdf24459e8 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 <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> 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 <paul.walmsley@sifive.com> 
  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 <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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 <paul.walmsley@sifive.com>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 120 2019-05-24T15:39:02+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-23T09:14:57+00:00 588cb88cedd56cb8272c312aac59b5e204f036a7 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see the file copying or write to the free software foundation inc extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 12 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091651.231300438@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not see the file copying or write to the free
  software foundation inc

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 12 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190523091651.231300438@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>