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treewide: Add SPDX license identifier - Makefile/Kconfig Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-19 05:07:45 -07:00
# SPDX-License-Identifier: GPL-2.0-only
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# Copied from arch/tile/kernel/vdso/Makefile
vdso: Improve cmd_vdso_check to check all dynamic relocations The actual intention is that no dynamic relocation exists in the VDSO. For this the VDSO build validates that the resulting .so file does not have any relocations which are specified via $(ARCH_REL_TYPE_ABS) per architecture, which is fragile as e.g. ARM64 lacks an entry for R_AARCH64_RELATIVE. Aside of that ARCH_REL_TYPE_ABS is a misnomer as it checks for relative relocations too. However, some GNU ld ports produce unneeded R_*_NONE relocation entries. If a port fails to determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE relocations. E.g. ld's powerpc port recently fixed https://sourceware.org/bugzilla/show_bug.cgi?id=29540). R_*_NONE are generally a no-op in the dynamic loaders. So just ignore them. Remove the ARCH_REL_TYPE_ABS defines and just validate that the resulting .so file does not contain any R_* relocation entries except R_*_NONE. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for aarch64 Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for vDSO, aarch64 Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com
2023-03-10 12:07:50 -07:00
# Include the generic Makefile to check the built vdso.
riscv: use vDSO common flow to reduce the latency of the time-related functions Even if RISC-V has supported the vDSO feature, the latency of the functions for obtaining the system time is still expensive. It is because these functions still trigger a corresponding system call in the process, which slows down the response time. If we want to remove the system call to reduce the latency, the kernel should have the ability to output the system clock information to userspace. This patch introduces the vDSO common flow to enable the kernel to achieve the above feature and uses "rdtime" instruction to obtain the current time in the user space. Under this condition, the latency cost by the ecall from U-mode to S-mode can be eliminated. After applying this patch, the latency of gettimeofday() measured on the HiFive unleashed board can be reduced by %61. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 07:14:48 -07:00
include $(srctree)/lib/vdso/Makefile
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# Symbols present in the vdso
RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu For now these are just placeholders that execute the syscall. We will later optimize them to avoid kernel crossings, but we'd like to have the VDSO entries from the first released kernel version to make the ABI simpler. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-23 15:42:14 -07:00
vdso-syms = rt_sigreturn
riscv: Use latest system call ABI We don't yet have an upstream glibc port for riscv, so there is no user space for the existing ABI, and we can remove the definitions for 32-bit time_t, off_t and struct resource and system calls based on them, including the vdso. Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-18 09:43:12 -07:00
ifdef CONFIG_64BIT
riscv: use vDSO common flow to reduce the latency of the time-related functions Even if RISC-V has supported the vDSO feature, the latency of the functions for obtaining the system time is still expensive. It is because these functions still trigger a corresponding system call in the process, which slows down the response time. If we want to remove the system call to reduce the latency, the kernel should have the ability to output the system clock information to userspace. This patch introduces the vDSO common flow to enable the kernel to achieve the above feature and uses "rdtime" instruction to obtain the current time in the user space. Under this condition, the latency cost by the ecall from U-mode to S-mode can be eliminated. After applying this patch, the latency of gettimeofday() measured on the HiFive unleashed board can be reduced by %61. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 07:14:48 -07:00
vdso-syms += vgettimeofday
riscv: Use latest system call ABI We don't yet have an upstream glibc port for riscv, so there is no user space for the existing ABI, and we can remove the definitions for 32-bit time_t, off_t and struct resource and system calls based on them, including the vdso. Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-18 09:43:12 -07:00
endif
RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu For now these are just placeholders that execute the syscall. We will later optimize them to avoid kernel crossings, but we'd like to have the VDSO entries from the first released kernel version to make the ABI simpler. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-23 15:42:14 -07:00
vdso-syms += getcpu
RISC-V: Allow userspace to flush the instruction cache Despite RISC-V having a direct 'fence.i' instruction available to userspace (which we can't trap!), that's not actually viable when running on Linux because the kernel might schedule a process on another hart. There is no way for userspace to handle this without invoking the kernel (as it doesn't know the thread->hart mappings), so we've defined a RISC-V specific system call to flush the instruction cache. This patch adds both a system call and a VDSO entry. If possible, we'd like to avoid having the system call be considered part of the user-facing ABI and instead restrict that to the VDSO entry -- both just in general to avoid having additional user-visible ABI to maintain, and because we'd prefer that users just call the VDSO entry because there might be a better way to do this in the future (ie, one that doesn't require entering the kernel). Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-10-25 14:32:16 -07:00
vdso-syms += flush_icache
RISC-V: Add hwprobe vDSO function and data Add a vDSO function __vdso_riscv_hwprobe, which can sit in front of the riscv_hwprobe syscall and answer common queries. We stash a copy of static answers for the "all CPUs" case in the vDSO data page. This data is private to the vDSO, so we can decide later to change what's stored there or under what conditions we defer to the syscall. Currently all data can be discovered at boot, so the vDSO function answers all queries when the cpumask is set to the "all CPUs" hint. There's also a boolean in the data that lets the vDSO function know that all CPUs are the same. In that case, the vDSO will also answer queries for arbitrary CPU masks in addition to the "all CPUs" hint. Signed-off-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20230407231103.2622178-7-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-07 16:11:03 -07:00
vdso-syms += hwprobe
vdso-syms += sys_hwprobe
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# Files to link into the vdso
riscv: add Linux note to vdso The Linux note in the vdso allows glibc to check the running kernel version without having to issue the uname syscall. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-04-27 08:13:34 -07:00
obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
riscv: disable stack-protector for vDSO Currently, building the vDSO with clang leads assembler errors like the following: /tmp/vgettimeofday-1ae0d2.s: Assembler messages: /tmp/vgettimeofday-1ae0d2.s:28: Error: bad expression /tmp/vgettimeofday-1ae0d2.s:28: Error: illegal operands `auipc a2,%got_pcrel_hi(__stack_chk_guard)' Disable the stack-protector for vDSO to fix these. Link: https://github.com/ClangBuiltLinux/linux/issues/1112 Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-29 00:51:29 -07:00
ccflags-y := -fno-stack-protector
riscv: vdso: fix section overlapping under some conditions lkp reported a build error, I tried the config and can reproduce build error as below: VDSOLD arch/riscv/kernel/vdso/vdso.so.dbg ld.lld: error: section .note file range overlaps with .text >>> .note range is [0x7C8, 0x803] >>> .text range is [0x800, 0x1993] ld.lld: error: section .text file range overlaps with .dynamic >>> .text range is [0x800, 0x1993] >>> .dynamic range is [0x808, 0x937] ld.lld: error: section .note virtual address range overlaps with .text >>> .note range is [0x7C8, 0x803] >>> .text range is [0x800, 0x1993] Fix it by setting DISABLE_BRANCH_PROFILING which will disable branch tracing for vdso, thus avoid useless _ftrace_annotated_branch section and _ftrace_branch section. Although we can also fix it by removing the hardcoded .text begin address, but I think that's another story and should be put into another patch. Link: https://lore.kernel.org/lkml/202210122123.Cc4FPShJ-lkp@intel.com/#r Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/r/20221102170254.1925-1-jszhang@kernel.org Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-11-02 10:02:54 -07:00
ccflags-y += -DDISABLE_BRANCH_PROFILING
riscv: vdso: Prevent the compiler from inserting calls to memset() The compiler is smart enough to insert a call to memset() in riscv_vdso_get_cpus(), which generates a dynamic relocation. So prevent this by using -fno-builtin option. Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API") Cc: stable@vger.kernel.org Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20241016083625.136311-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-16 01:36:24 -07:00
ccflags-y += -fno-builtin
riscv: disable stack-protector for vDSO Currently, building the vDSO with clang leads assembler errors like the following: /tmp/vgettimeofday-1ae0d2.s: Assembler messages: /tmp/vgettimeofday-1ae0d2.s:28: Error: bad expression /tmp/vgettimeofday-1ae0d2.s:28: Error: illegal operands `auipc a2,%got_pcrel_hi(__stack_chk_guard)' Disable the stack-protector for vDSO to fix these. Link: https://github.com/ClangBuiltLinux/linux/issues/1112 Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-29 00:51:29 -07:00
riscv: use vDSO common flow to reduce the latency of the time-related functions Even if RISC-V has supported the vDSO feature, the latency of the functions for obtaining the system time is still expensive. It is because these functions still trigger a corresponding system call in the process, which slows down the response time. If we want to remove the system call to reduce the latency, the kernel should have the ability to output the system clock information to userspace. This patch introduces the vDSO common flow to enable the kernel to achieve the above feature and uses "rdtime" instruction to obtain the current time in the user space. Under this condition, the latency cost by the ecall from U-mode to S-mode can be eliminated. After applying this patch, the latency of gettimeofday() measured on the HiFive unleashed board can be reduced by %61. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 07:14:48 -07:00
ifneq ($(c-gettimeofday-y),)
riscv: Add -fPIC option to CFLAGS_vgettimeofday.o The time related vDSO functions use a variable, vdso_data, to access the vDSO data page to get the system time information. Because the vdso_data for CFLAGS_vgettimeofday.o is an external variable defined in vdso.o, the CFLAGS_vgettimeofday.o should be compiled with -fPIC to ensure that vdso_data is addressable. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-22 18:13:22 -07:00
CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
riscv: use vDSO common flow to reduce the latency of the time-related functions Even if RISC-V has supported the vDSO feature, the latency of the functions for obtaining the system time is still expensive. It is because these functions still trigger a corresponding system call in the process, which slows down the response time. If we want to remove the system call to reduce the latency, the kernel should have the ability to output the system clock information to userspace. This patch introduces the vDSO common flow to enable the kernel to achieve the above feature and uses "rdtime" instruction to obtain the current time in the user space. Under this condition, the latency cost by the ecall from U-mode to S-mode can be eliminated. After applying this patch, the latency of gettimeofday() measured on the HiFive unleashed board can be reduced by %61. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-09 07:14:48 -07:00
endif
RISC-V: Add hwprobe vDSO function and data Add a vDSO function __vdso_riscv_hwprobe, which can sit in front of the riscv_hwprobe syscall and answer common queries. We stash a copy of static answers for the "all CPUs" case in the vDSO data page. This data is private to the vDSO, so we can decide later to change what's stored there or under what conditions we defer to the syscall. Currently all data can be discovered at boot, so the vDSO function answers all queries when the cpumask is set to the "all CPUs" hint. There's also a boolean in the data that lets the vDSO function know that all CPUs are the same. In that case, the vDSO will also answer queries for arbitrary CPU masks in addition to the "all CPUs" hint. Signed-off-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20230407231103.2622178-7-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-07 16:11:03 -07:00
CFLAGS_hwprobe.o += -fPIC
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# Build rules
riscv: explicitly use symbol offsets for VDSO The current implementation of the `__rt_sigaction` reference computed an absolute offset relative to the mapped base of the VDSO. While this can be handled in the medlow model, the medany model cannot handle this as it is meant to be position independent. The current implementation relied on the BFD linker relaxing the PC-relative relocation into an absolute relocation as it was a near-zero address allowing it to be referenced relative to `zero`. We now extract the offsets and create a generated header allowing the build with LLVM and lld to succeed as we no longer depend on the linker rewriting address references near zero. This change was largely modelled after the ARM64 target which does something similar. Signed-off-by: Saleem Abdulrasool <abdulras@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-04 10:32:14 -07:00
targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
riscv: explicitly use symbol offsets for VDSO The current implementation of the `__rt_sigaction` reference computed an absolute offset relative to the mapped base of the VDSO. While this can be handled in the medlow model, the medany model cannot handle this as it is meant to be position independent. The current implementation relied on the BFD linker relaxing the PC-relative relocation into an absolute relocation as it was a near-zero address allowing it to be referenced relative to `zero`. We now extract the offsets and create a generated header allowing the build with LLVM and lld to succeed as we no longer depend on the linker rewriting address references near zero. This change was largely modelled after the ARM64 target which does something similar. Signed-off-by: Saleem Abdulrasool <abdulras@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-04 10:32:14 -07:00
obj-y += vdso.o
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
RISC-V: vdso: Do not add missing symbols to version section in linker script Recently, ld.lld moved from '--undefined-version' to '--no-undefined-version' as the default, which breaks the compat vDSO build: ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_gettimeofday' failed: symbol not defined ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_gettime' failed: symbol not defined ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_getres' failed: symbol not defined These symbols are not present in the compat vDSO or the regular vDSO for 32-bit but they are unconditionally included in the version section of the linker script, which is prohibited with '--no-undefined-version'. Fix this issue by only including the symbols that are actually exported in the version section of the linker script. Link: https://github.com/ClangBuiltLinux/linux/issues/1756 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221108171324.3377226-1-nathan@kernel.org/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-11-08 10:13:23 -07:00
ifneq ($(filter vgettimeofday, $(vdso-syms)),)
CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY
endif
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
riscv: Fixup __vdso_gettimeofday broke dynamic ftrace For linux-5.8-rc1, enable ftrace of riscv will cause boot panic: [ 2.388980] Run /sbin/init as init process [ 2.529938] init[39]: unhandled signal 4 code 0x1 at 0x0000003ff449e000 [ 2.531078] CPU: 0 PID: 39 Comm: init Not tainted 5.8.0-rc1-dirty #13 [ 2.532719] epc: 0000003ff449e000 ra : 0000003ff449e954 sp : 0000003fffedb900 [ 2.534005] gp : 00000000000e8528 tp : 0000003ff449d800 t0 : 000000000000001e [ 2.534965] t1 : 000000000000000a t2 : 0000003fffedb89e s0 : 0000003fffedb920 [ 2.536279] s1 : 0000003fffedb940 a0 : 0000003ff43d4b2c a1 : 0000000000000000 [ 2.537334] a2 : 0000000000000001 a3 : 0000000000000000 a4 : fffffffffbad8000 [ 2.538466] a5 : 0000003ff449e93a a6 : 0000000000000000 a7 : 0000000000000000 [ 2.539511] s2 : 0000000000000000 s3 : 0000003ff448412c s4 : 0000000000000010 [ 2.541260] s5 : 0000000000000016 s6 : 00000000000d0a30 s7 : 0000003fffedba70 [ 2.542152] s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000003fffedb960 [ 2.543335] s11: 0000000000000000 t3 : 0000000000000000 t4 : 0000003fffedb8a0 [ 2.544471] t5 : 0000000000000000 t6 : 0000000000000000 [ 2.545730] status: 0000000000004020 badaddr: 00000000464c457f cause: 0000000000000002 [ 2.549867] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 [ 2.551267] CPU: 0 PID: 1 Comm: init Not tainted 5.8.0-rc1-dirty #13 [ 2.552061] Call Trace: [ 2.552626] [<ffffffe00020374a>] walk_stackframe+0x0/0xc4 [ 2.553486] [<ffffffe0002039f4>] show_stack+0x40/0x4c [ 2.553995] [<ffffffe00054a6ae>] dump_stack+0x7a/0x98 [ 2.554615] [<ffffffe00020b9b8>] panic+0x114/0x2f4 [ 2.555395] [<ffffffe00020ebd6>] do_exit+0x89c/0x8c2 [ 2.555949] [<ffffffe00020f930>] do_group_exit+0x3a/0x90 [ 2.556715] [<ffffffe000219e08>] get_signal+0xe2/0x6e6 [ 2.557388] [<ffffffe000202d72>] do_notify_resume+0x6a/0x37a [ 2.558089] [<ffffffe000201c16>] ret_from_exception+0x0/0xc "ra:0x3ff449e954" is the return address of "call _mcount" in the prologue of __vdso_gettimeofday(). Without proper relocate, pc jmp to 0x0000003ff449e000 (vdso map base) with a illegal instruction trap. The solution comes from arch/arm64/kernel/vdso/Makefile: CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) - CC_FLAGS_SCS is ShadowCallStack feature in Clang and only implemented for arm64, no use for riscv. Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Cc: stable@vger.kernel.org Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-23 02:50:54 -07:00
# Disable -pg to prevent insert call site
riscv: Implement Shadow Call Stack Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the compiler injects instructions to all non-leaf C functions to store the return address to the shadow stack and unconditionally load it again before returning, which makes it harder to corrupt the return address through a stack overflow, for example. The active shadow call stack pointer is stored in the gp register, which makes SCS incompatible with gp relaxation. Use --no-relax-gp to ensure gp relaxation is disabled and disable global pointer loading. Add SCS pointers to struct thread_info, implement SCS initialization, and task switching Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-27 15:48:02 -07:00
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
riscv: hwprobe: do not produce frtace relocation Such relocation causes crash of android linker similar to one described in commit e05d57dcb8c7 ("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace"). Looks like this relocation is added by CONFIG_DYNAMIC_FTRACE which is disabled in the default android kernel. Before: readelf -rW arch/riscv/kernel/vdso/vdso.so: Relocation section '.rela.dyn' at offset 0xd00 contains 1 entry: Offset Info Type 0000000000000d20 0000000000000003 R_RISCV_RELATIVE objdump: 0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>: c86: 0001 nop c88: 0001 nop c8a: 0001 nop c8c: 0001 nop c8e: e211 bnez a2,c92 <__vdso_riscv_hwprobe... After: readelf -rW arch/riscv/kernel/vdso/vdso.so: There are no relocations in this file. objdump: 0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>: c86: e211 bnez a2,c8a <__vdso_riscv_hwprobe... c88: c6b9 beqz a3,cd6 <__vdso_riscv_hwprobe... c8a: e739 bnez a4,cd8 <__vdso_riscv_hwprobe... c8c: ffffd797 auipc a5,0xffffd Also disable SCS since it also should not be available in vdso. Fixes: aa5af0aa90ba ("RISC-V: Add hwprobe vDSO function and data") Signed-off-by: Roman Artemev <roman.artemev@syntacore.com> Signed-off-by: Vladimir Isaev <vladimir.isaev@syntacore.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20240313085843.17661-1-vladimir.isaev@syntacore.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-13 00:35:46 -07:00
CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
riscv: Fixup __vdso_gettimeofday broke dynamic ftrace For linux-5.8-rc1, enable ftrace of riscv will cause boot panic: [ 2.388980] Run /sbin/init as init process [ 2.529938] init[39]: unhandled signal 4 code 0x1 at 0x0000003ff449e000 [ 2.531078] CPU: 0 PID: 39 Comm: init Not tainted 5.8.0-rc1-dirty #13 [ 2.532719] epc: 0000003ff449e000 ra : 0000003ff449e954 sp : 0000003fffedb900 [ 2.534005] gp : 00000000000e8528 tp : 0000003ff449d800 t0 : 000000000000001e [ 2.534965] t1 : 000000000000000a t2 : 0000003fffedb89e s0 : 0000003fffedb920 [ 2.536279] s1 : 0000003fffedb940 a0 : 0000003ff43d4b2c a1 : 0000000000000000 [ 2.537334] a2 : 0000000000000001 a3 : 0000000000000000 a4 : fffffffffbad8000 [ 2.538466] a5 : 0000003ff449e93a a6 : 0000000000000000 a7 : 0000000000000000 [ 2.539511] s2 : 0000000000000000 s3 : 0000003ff448412c s4 : 0000000000000010 [ 2.541260] s5 : 0000000000000016 s6 : 00000000000d0a30 s7 : 0000003fffedba70 [ 2.542152] s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000003fffedb960 [ 2.543335] s11: 0000000000000000 t3 : 0000000000000000 t4 : 0000003fffedb8a0 [ 2.544471] t5 : 0000000000000000 t6 : 0000000000000000 [ 2.545730] status: 0000000000004020 badaddr: 00000000464c457f cause: 0000000000000002 [ 2.549867] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 [ 2.551267] CPU: 0 PID: 1 Comm: init Not tainted 5.8.0-rc1-dirty #13 [ 2.552061] Call Trace: [ 2.552626] [<ffffffe00020374a>] walk_stackframe+0x0/0xc4 [ 2.553486] [<ffffffe0002039f4>] show_stack+0x40/0x4c [ 2.553995] [<ffffffe00054a6ae>] dump_stack+0x7a/0x98 [ 2.554615] [<ffffffe00020b9b8>] panic+0x114/0x2f4 [ 2.555395] [<ffffffe00020ebd6>] do_exit+0x89c/0x8c2 [ 2.555949] [<ffffffe00020f930>] do_group_exit+0x3a/0x90 [ 2.556715] [<ffffffe000219e08>] get_signal+0xe2/0x6e6 [ 2.557388] [<ffffffe000202d72>] do_notify_resume+0x6a/0x37a [ 2.558089] [<ffffffe000201c16>] ret_from_exception+0x0/0xc "ra:0x3ff449e954" is the return address of "call _mcount" in the prologue of __vdso_gettimeofday(). Without proper relocate, pc jmp to 0x0000003ff449e000 (vdso map base) with a illegal instruction trap. The solution comes from arch/arm64/kernel/vdso/Makefile: CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) - CC_FLAGS_SCS is ShadowCallStack feature in Clang and only implemented for arm64, no use for riscv. Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Cc: stable@vger.kernel.org Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-23 02:50:54 -07:00
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# Force dependency
$(obj)/vdso.o: $(obj)/vdso.so
# link rule for the .so file, .lds has to be first
riscv: vdso: fix and clean-up Makefile Running "make" on an already compiled kernel tree will rebuild the kernel even without any modifications: CALL linux/scripts/checksyscalls.sh CALL linux/scripts/atomic/check-atomics.sh CHK include/generated/compile.h SO2S arch/riscv/kernel/vdso/vdso-syms.S AS arch/riscv/kernel/vdso/vdso-syms.o AR arch/riscv/kernel/vdso/built-in.a AR arch/riscv/kernel/built-in.a AR arch/riscv/built-in.a GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o The reason is "Any target that utilizes if_changed must be listed in $(targets), otherwise the command line check will fail, and the target will always be built" as explained by Documentation/kbuild/makefiles.rst Fix this build bug by adding vdso-syms.S to $(targets) At the same time, there are two trivial clean up modifications: - the vdso-dummy.o is not needed any more after so remove it. - vdso.lds is a generated file, so it should be prefixed with $(obj)/ instead of $(src)/ Fixes: c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+") Cc: stable@vger.kernel.org Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-02 06:29:08 -07:00
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
$(call if_changed,vdsold)
riscv: vdso: do not strip debugging info for vdso.so.dbg The vdso.so.dbg is a debug version of vdso and could be used for debugging purpose. For example, perf-annotate requires debugging info to show source lines. So let's keep its debugging info. Signed-off-by: Changbin Du <changbin.du@huawei.com> Reviewed-by: Cyril Bur <cyrilbur@tenstorrent.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240611040947.3024710-1-changbin.du@huawei.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-10 21:09:47 -07:00
LDFLAGS_vdso.so.dbg = -shared -soname=linux-vdso.so.1 \
riscv: Use $(LD) instead of $(CC) to link vDSO Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When linking with clang, there are a couple of warnings about flags that will not be used during the link: clang-12: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument] clang-12: warning: argument unused during compilation: '-pg' [-Wunused-command-line-argument] '-no-pie' was added in commit 85602bea297f ("RISC-V: build vdso-dummy.o with -no-pie") to override '-pie' getting added to the ld command from distribution versions of GCC that enable PIE by default. It is technically no longer needed after commit c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+"), which removed vdso-dummy.o in favor of generating vdso-syms.S from vdso.so with $(NM) but this also resolves the issue in case it ever comes back due to having full control over the $(LD) command. '-pg' is for function tracing, it is not used during linking as clang states. These flags could be removed/filtered to fix the warnings but it is easier to just match the rest of the kernel and use $(LD) directly for linking. See commits fe00e50b2db8 ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO") 691efbedc60d ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO") 2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO") 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") for more information. The flags are converted to linker flags and '--eh-frame-hdr' is added to match what is added by GCC implicitly, which can be seen by adding '-v' to GCC's invocation. Additionally, since this area is being modified, use the $(OBJCOPY) variable instead of an open coded $(CROSS_COMPILE)objcopy so that the user's choice of objcopy binary is respected. Link: https://github.com/ClangBuiltLinux/linux/issues/803 Link: https://github.com/ClangBuiltLinux/linux/issues/970 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-25 14:51:56 -07:00
--build-id=sha1 --hash-style=both --eh-frame-hdr
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
riscv: explicitly use symbol offsets for VDSO The current implementation of the `__rt_sigaction` reference computed an absolute offset relative to the mapped base of the VDSO. While this can be handled in the medlow model, the medany model cannot handle this as it is meant to be position independent. The current implementation relied on the BFD linker relaxing the PC-relative relocation into an absolute relocation as it was a near-zero address allowing it to be referenced relative to `zero`. We now extract the offsets and create a generated header allowing the build with LLVM and lld to succeed as we no longer depend on the linker rewriting address references near zero. This change was largely modelled after the ARM64 target which does something similar. Signed-off-by: Saleem Abdulrasool <abdulras@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-04 10:32:14 -07:00
# Generate VDSO offsets using helper script
kbuild: use $(src) instead of $(srctree)/$(src) for source directory Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-04-27 07:55:02 -07:00
gen-vdsosym := $(src)/gen_vdso_offsets.sh
riscv: explicitly use symbol offsets for VDSO The current implementation of the `__rt_sigaction` reference computed an absolute offset relative to the mapped base of the VDSO. While this can be handled in the medlow model, the medany model cannot handle this as it is meant to be position independent. The current implementation relied on the BFD linker relaxing the PC-relative relocation into an absolute relocation as it was a near-zero address allowing it to be referenced relative to `zero`. We now extract the offsets and create a generated header allowing the build with LLVM and lld to succeed as we no longer depend on the linker rewriting address references near zero. This change was largely modelled after the ARM64 target which does something similar. Signed-off-by: Saleem Abdulrasool <abdulras@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-04 10:32:14 -07:00
quiet_cmd_vdsosym = VDSOSYM $@
cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
$(call if_changed,vdsosym)
RISC-V: User-facing API This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:07:09 -07:00
# actual build commands
# The DSO images are built using a special linker script
# Make sure only to export the intended __vdso_xxx symbol offsets.
quiet_cmd_vdsold = VDSOLD $@
riscv: Use $(LD) instead of $(CC) to link vDSO Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When linking with clang, there are a couple of warnings about flags that will not be used during the link: clang-12: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument] clang-12: warning: argument unused during compilation: '-pg' [-Wunused-command-line-argument] '-no-pie' was added in commit 85602bea297f ("RISC-V: build vdso-dummy.o with -no-pie") to override '-pie' getting added to the ld command from distribution versions of GCC that enable PIE by default. It is technically no longer needed after commit c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+"), which removed vdso-dummy.o in favor of generating vdso-syms.S from vdso.so with $(NM) but this also resolves the issue in case it ever comes back due to having full control over the $(LD) command. '-pg' is for function tracing, it is not used during linking as clang states. These flags could be removed/filtered to fix the warnings but it is easier to just match the rest of the kernel and use $(LD) directly for linking. See commits fe00e50b2db8 ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO") 691efbedc60d ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO") 2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO") 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") for more information. The flags are converted to linker flags and '--eh-frame-hdr' is added to match what is added by GCC implicitly, which can be seen by adding '-v' to GCC's invocation. Additionally, since this area is being modified, use the $(OBJCOPY) variable instead of an open coded $(CROSS_COMPILE)objcopy so that the user's choice of objcopy binary is respected. Link: https://github.com/ClangBuiltLinux/linux/issues/803 Link: https://github.com/ClangBuiltLinux/linux/issues/970 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-25 14:51:56 -07:00
cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
$(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
riscv: delete temporary files 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 <ilie.halip@gmail.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2020-01-15 04:32:42 -07:00
rm $@.tmp
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