| Message ID | 20250122-riscv_optimize_entry-v1-3-4ee95559cfd0@rivosinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | entry: Move ret_from_fork() to C and inline syscall_exit_to_user_mode() | expand |
Hi Charlie, kernel test robot noticed the following build errors: [auto build test ERROR on ffd294d346d185b70e28b1a28abe367bbfe53c04] url: https://github.com/intel-lab-lkp/linux/commits/Charlie-Jenkins/riscv-entry-Convert-ret_from_fork-to-C/20250123-065957 base: ffd294d346d185b70e28b1a28abe367bbfe53c04 patch link: https://lore.kernel.org/r/20250122-riscv_optimize_entry-v1-3-4ee95559cfd0%40rivosinc.com patch subject: [PATCH 3/4] loongarch: entry: Migrate ret_from_fork() to C config: loongarch-allnoconfig (https://download.01.org/0day-ci/archive/20250124/202501240042.hEXt9u9r-lkp@intel.com/config) compiler: loongarch64-linux-gcc (GCC) 14.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250124/202501240042.hEXt9u9r-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202501240042.hEXt9u9r-lkp@intel.com/ All errors (new ones prefixed by >>): arch/loongarch/kernel/process.c: In function 'ret_from_kernel_thread': >> arch/loongarch/kernel/process.c:76:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 76 | { | ^ arch/loongarch/kernel/process.c:105:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 105 | { | ^ arch/loongarch/kernel/process.c:110:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 110 | { | ^ arch/loongarch/kernel/process.c:114:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 114 | { | ^ arch/loongarch/kernel/process.c:151:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 151 | { | ^ arch/loongarch/kernel/process.c:160:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 160 | { | ^ arch/loongarch/kernel/process.c:169:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 169 | { | ^ arch/loongarch/kernel/process.c:234:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 234 | { | ^ arch/loongarch/kernel/process.c:257:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 257 | { | ^ arch/loongarch/kernel/process.c:279:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 279 | { | ^ arch/loongarch/kernel/process.c:296:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 296 | { | ^ arch/loongarch/kernel/process.c:317:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 317 | { | ^ arch/loongarch/kernel/process.c:338:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 338 | { | ^ In file included from include/asm-generic/percpu.h:7, from arch/loongarch/include/asm/percpu.h:184, from include/linux/irqflags.h:19, from include/linux/spinlock.h:59, from include/linux/sched.h:2171, from include/linux/ratelimit.h:6, from include/linux/dev_printk.h:16, from include/linux/device.h:15, from include/linux/node.h:18, from include/linux/cpu.h:17, from arch/loongarch/kernel/process.c:13: >> arch/loongarch/kernel/process.c:345:43: error: storage class specified for parameter 'backtrace_csd' 345 | static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); | ^~~~~~~~~~~~~ include/linux/percpu-defs.h:104:44: note: in definition of macro 'DEFINE_PER_CPU_SECTION' 104 | __PCPU_ATTRS(sec) __typeof__(type) name | ^~~~ arch/loongarch/kernel/process.c:345:8: note: in expansion of macro 'DEFINE_PER_CPU' 345 | static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); | ^~~~~~~~~~~~~~ >> arch/loongarch/kernel/process.c:345:43: error: section attribute not allowed for 'backtrace_csd' 345 | static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); | ^~~~~~~~~~~~~ include/linux/percpu-defs.h:104:44: note: in definition of macro 'DEFINE_PER_CPU_SECTION' 104 | __PCPU_ATTRS(sec) __typeof__(type) name | ^~~~ arch/loongarch/kernel/process.c:345:8: note: in expansion of macro 'DEFINE_PER_CPU' 345 | static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); | ^~~~~~~~~~~~~~ >> arch/loongarch/kernel/process.c:346:23: error: storage class specified for parameter 'backtrace_csd_busy' 346 | static struct cpumask backtrace_csd_busy; | ^~~~~~~~~~~~~~~~~~ arch/loongarch/kernel/process.c:349:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 349 | { | ^ arch/loongarch/kernel/process.c:355:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 355 | { | ^ arch/loongarch/kernel/process.c:379:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 379 | { | ^ arch/loongarch/kernel/process.c:385:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token 385 | { | ^ >> arch/loongarch/kernel/process.c:70:35: error: old-style parameter declarations in prototyped function definition 70 | void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struct *prev, | ^~~~~~~~~~~~~~~~~~~~~~ >> arch/loongarch/kernel/process.c:402: error: expected '{' at end of input vim +76 arch/loongarch/kernel/process.c 803b0fc5c3f2baa Huacai Chen 2022-05-31 @13 #include <linux/cpu.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 14 #include <linux/init.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 15 #include <linux/kernel.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 16 #include <linux/errno.h> 5c881018646d666 Charlie Jenkins 2025-01-22 17 #include <linux/entry-common.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 18 #include <linux/sched.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 19 #include <linux/sched/debug.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 20 #include <linux/sched/task.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 21 #include <linux/sched/task_stack.h> edffa33c7bb5a73 Qing Zhang 2023-02-25 22 #include <linux/hw_breakpoint.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 23 #include <linux/mm.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 24 #include <linux/stddef.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 25 #include <linux/unistd.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 26 #include <linux/export.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 27 #include <linux/ptrace.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 28 #include <linux/mman.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 29 #include <linux/personality.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 30 #include <linux/sys.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 31 #include <linux/completion.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 32 #include <linux/kallsyms.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 33 #include <linux/random.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 34 #include <linux/prctl.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 35 #include <linux/nmi.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 36 803b0fc5c3f2baa Huacai Chen 2022-05-31 37 #include <asm/asm.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 38 #include <asm/bootinfo.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 39 #include <asm/cpu.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 40 #include <asm/elf.h> c718a0bad75ccef Bibo Mao 2023-09-20 41 #include <asm/exec.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 42 #include <asm/fpu.h> bd3c5798484aa9a Qi Hu 2023-09-06 43 #include <asm/lbt.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 44 #include <asm/io.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 45 #include <asm/irq.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 46 #include <asm/irq_regs.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 47 #include <asm/loongarch.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 48 #include <asm/pgtable.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 49 #include <asm/processor.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 50 #include <asm/reg.h> 5c881018646d666 Charlie Jenkins 2025-01-22 51 #include <asm/switch_to.h> 49232773d8233ed Qing Zhang 2022-08-06 52 #include <asm/unwind.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 53 #include <asm/vdso.h> 803b0fc5c3f2baa Huacai Chen 2022-05-31 54 09f33601bf940f9 Huacai Chen 2022-12-10 55 #ifdef CONFIG_STACKPROTECTOR 09f33601bf940f9 Huacai Chen 2022-12-10 56 #include <linux/stackprotector.h> 09f33601bf940f9 Huacai Chen 2022-12-10 57 unsigned long __stack_chk_guard __read_mostly; 09f33601bf940f9 Huacai Chen 2022-12-10 58 EXPORT_SYMBOL(__stack_chk_guard); 09f33601bf940f9 Huacai Chen 2022-12-10 59 #endif 09f33601bf940f9 Huacai Chen 2022-12-10 60 803b0fc5c3f2baa Huacai Chen 2022-05-31 61 /* 803b0fc5c3f2baa Huacai Chen 2022-05-31 62 * Idle related variables and functions 803b0fc5c3f2baa Huacai Chen 2022-05-31 63 */ 803b0fc5c3f2baa Huacai Chen 2022-05-31 64 803b0fc5c3f2baa Huacai Chen 2022-05-31 65 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; 803b0fc5c3f2baa Huacai Chen 2022-05-31 66 EXPORT_SYMBOL(boot_option_idle_override); 803b0fc5c3f2baa Huacai Chen 2022-05-31 67 5c881018646d666 Charlie Jenkins 2025-01-22 68 asmlinkage void restore_and_ret(void); 5c881018646d666 Charlie Jenkins 2025-01-22 69 asmlinkage void ret_from_fork_asm(void); 5c881018646d666 Charlie Jenkins 2025-01-22 @70 void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struct *prev, 5c881018646d666 Charlie Jenkins 2025-01-22 71 struct pt_regs *regs, 5c881018646d666 Charlie Jenkins 2025-01-22 72 int (*fn)(void *), 5c881018646d666 Charlie Jenkins 2025-01-22 73 void *fn_arg) 803b0fc5c3f2baa Huacai Chen 2022-05-31 74 803b0fc5c3f2baa Huacai Chen 2022-05-31 75 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) 803b0fc5c3f2baa Huacai Chen 2022-05-31 @76 { 803b0fc5c3f2baa Huacai Chen 2022-05-31 77 unsigned long crmd; 803b0fc5c3f2baa Huacai Chen 2022-05-31 78 unsigned long prmd; 803b0fc5c3f2baa Huacai Chen 2022-05-31 79 unsigned long euen; 803b0fc5c3f2baa Huacai Chen 2022-05-31 80 803b0fc5c3f2baa Huacai Chen 2022-05-31 81 /* New thread loses kernel privileges. */ 803b0fc5c3f2baa Huacai Chen 2022-05-31 82 crmd = regs->csr_crmd & ~(PLV_MASK); 803b0fc5c3f2baa Huacai Chen 2022-05-31 83 crmd |= PLV_USER; 803b0fc5c3f2baa Huacai Chen 2022-05-31 84 regs->csr_crmd = crmd; 803b0fc5c3f2baa Huacai Chen 2022-05-31 85 803b0fc5c3f2baa Huacai Chen 2022-05-31 86 prmd = regs->csr_prmd & ~(PLV_MASK); 803b0fc5c3f2baa Huacai Chen 2022-05-31 87 prmd |= PLV_USER; 803b0fc5c3f2baa Huacai Chen 2022-05-31 88 regs->csr_prmd = prmd; 803b0fc5c3f2baa Huacai Chen 2022-05-31 89 803b0fc5c3f2baa Huacai Chen 2022-05-31 90 euen = regs->csr_euen & ~(CSR_EUEN_FPEN); 803b0fc5c3f2baa Huacai Chen 2022-05-31 91 regs->csr_euen = euen; 803b0fc5c3f2baa Huacai Chen 2022-05-31 92 lose_fpu(0); bd3c5798484aa9a Qi Hu 2023-09-06 93 lose_lbt(0); c2396651309eba2 Xi Ruoyao 2024-01-17 94 current->thread.fpu.fcsr = boot_cpu_data.fpu_csr0; 803b0fc5c3f2baa Huacai Chen 2022-05-31 95 803b0fc5c3f2baa Huacai Chen 2022-05-31 96 clear_thread_flag(TIF_LSX_CTX_LIVE); 803b0fc5c3f2baa Huacai Chen 2022-05-31 97 clear_thread_flag(TIF_LASX_CTX_LIVE); bd3c5798484aa9a Qi Hu 2023-09-06 98 clear_thread_flag(TIF_LBT_CTX_LIVE); 803b0fc5c3f2baa Huacai Chen 2022-05-31 99 clear_used_math(); 803b0fc5c3f2baa Huacai Chen 2022-05-31 100 regs->csr_era = pc; 803b0fc5c3f2baa Huacai Chen 2022-05-31 101 regs->regs[3] = sp; 803b0fc5c3f2baa Huacai Chen 2022-05-31 102 } 803b0fc5c3f2baa Huacai Chen 2022-05-31 103
diff --git a/arch/loongarch/include/asm/switch_to.h b/arch/loongarch/include/asm/switch_to.h index 5b225aff3ba21aa06d0713bc8e73e1b941389630..a1c5576f1fd145670e13038bec6dd390486099ab 100644 --- a/arch/loongarch/include/asm/switch_to.h +++ b/arch/loongarch/include/asm/switch_to.h @@ -26,6 +26,14 @@ extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next, struct thread_info *next_ti, void *sched_ra, void *sched_cfa); +void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struct *prev, + struct pt_regs *regs, + int (*fn)(void *), + void *fn_arg); + +void noinstr __no_stack_protector ret_from_fork(struct task_struct *prev, + struct pt_regs *regs); + /* * For newly created kernel threads switch_to() will return to * ret_from_kernel_thread, newly created user threads to ret_from_fork. diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index 48e7e34e355e83eae8165957ba2eac05a8bf17df..2abc29e573810e000f2fef4646ddca0dbb80eabe 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -77,24 +77,22 @@ SYM_CODE_START(handle_syscall) SYM_CODE_END(handle_syscall) _ASM_NOKPROBE(handle_syscall) -SYM_CODE_START(ret_from_fork) +SYM_CODE_START(ret_from_fork_asm) UNWIND_HINT_REGS - bl schedule_tail # a0 = struct task_struct *prev - move a0, sp - bl syscall_exit_to_user_mode + move a1, sp + bl ret_from_fork RESTORE_STATIC RESTORE_SOME RESTORE_SP_AND_RET -SYM_CODE_END(ret_from_fork) +SYM_CODE_END(ret_from_fork_asm) -SYM_CODE_START(ret_from_kernel_thread) +SYM_CODE_START(ret_from_kernel_thread_asm) UNWIND_HINT_REGS - bl schedule_tail # a0 = struct task_struct *prev - move a0, s1 - jirl ra, s0, 0 - move a0, sp - bl syscall_exit_to_user_mode + move a1, sp + move a2, s0 + move a3, s1 + bl ret_from_kernel_thread RESTORE_STATIC RESTORE_SOME RESTORE_SP_AND_RET -SYM_CODE_END(ret_from_kernel_thread) +SYM_CODE_END(ret_from_kernel_thread_asm) diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c index 6e58f65455c7ca3eae2e88ed852c8655a6701e5c..9bb069ef363fefed1f2115e6572b31c2b76bb414 100644 --- a/arch/loongarch/kernel/process.c +++ b/arch/loongarch/kernel/process.c @@ -14,6 +14,7 @@ #include <linux/init.h> #include <linux/kernel.h> #include <linux/errno.h> +#include <linux/entry-common.h> #include <linux/sched.h> #include <linux/sched/debug.h> #include <linux/sched/task.h> @@ -47,6 +48,7 @@ #include <asm/pgtable.h> #include <asm/processor.h> #include <asm/reg.h> +#include <asm/switch_to.h> #include <asm/unwind.h> #include <asm/vdso.h> @@ -63,8 +65,12 @@ EXPORT_SYMBOL(__stack_chk_guard); unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; EXPORT_SYMBOL(boot_option_idle_override); -asmlinkage void ret_from_fork(void); -asmlinkage void ret_from_kernel_thread(void); +asmlinkage void restore_and_ret(void); +asmlinkage void ret_from_fork_asm(void); +void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struct *prev, + struct pt_regs *regs, + int (*fn)(void *), + void *fn_arg) void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) { @@ -138,6 +144,24 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) return 0; } +void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struct *prev, + struct pt_regs *regs, + int (*fn)(void *), + void *fn_arg) +{ + schedule_tail(prev); + + fn(fn_arg); + + syscall_exit_to_user_mode(regs); +} + +void noinstr __no_stack_protector ret_from_fork(struct task_struct *prev, struct pt_regs *regs) +{ + schedule_tail(prev); + syscall_exit_to_user_mode(regs); +} + /* * Copy architecture-specific thread state */ @@ -165,8 +189,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) p->thread.reg03 = childksp; p->thread.reg23 = (unsigned long)args->fn; p->thread.reg24 = (unsigned long)args->fn_arg; - p->thread.reg01 = (unsigned long)ret_from_kernel_thread; - p->thread.sched_ra = (unsigned long)ret_from_kernel_thread; + p->thread.reg01 = (unsigned long)ret_from_kernel_thread_asm; + p->thread.sched_ra = (unsigned long)ret_from_kernel_thread_asm; memset(childregs, 0, sizeof(struct pt_regs)); childregs->csr_euen = p->thread.csr_euen; childregs->csr_crmd = p->thread.csr_crmd; @@ -182,8 +206,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childregs->regs[3] = usp; p->thread.reg03 = (unsigned long) childregs; - p->thread.reg01 = (unsigned long) ret_from_fork; - p->thread.sched_ra = (unsigned long) ret_from_fork; + p->thread.reg01 = (unsigned long) ret_from_fork_asm; + p->thread.sched_ra = (unsigned long) ret_from_fork_asm; /* * New tasks lose permission to use the fpu. This accelerates context
Loongarch is the only architecture that calls syscall_exit_to_user_mode() from asm. Move the call into C so that this function can be inlined across all architectures. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> --- arch/loongarch/include/asm/switch_to.h | 8 ++++++++ arch/loongarch/kernel/entry.S | 22 ++++++++++----------- arch/loongarch/kernel/process.c | 36 ++++++++++++++++++++++++++++------ 3 files changed, 48 insertions(+), 18 deletions(-)