diff options
| -rw-r--r-- | arch/arm64/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 36 | ||||
| -rw-r--r-- | arch/arm64/kernel/syscall.c | 47 | ||||
| -rw-r--r-- | arch/arm64/kernel/traps.c | 16 |
4 files changed, 59 insertions, 43 deletions
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 0025f8691046..4e24d2244bd1 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -18,7 +18,8 @@ arm64-obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ hyp-stub.o psci.o cpu_ops.o insn.o \ return_address.o cpuinfo.o cpu_errata.o \ cpufeature.o alternative.o cacheinfo.o \ - smp.o smp_spin_table.o topology.o smccc-call.o + smp.o smp_spin_table.o topology.o smccc-call.o \ + syscall.o extra-$(CONFIG_EFI) := efi-entry.o diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 201809537343..2045aec79ccb 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -903,7 +903,6 @@ ENDPROC(el0_error) */ ret_fast_syscall: disable_daif - str x0, [sp, #S_X0] // returned x0 #ifndef CONFIG_DEBUG_RSEQ ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK @@ -978,15 +977,11 @@ el0_svc_naked: // compat entry point tst x16, #_TIF_SYSCALL_WORK // check for syscall hooks b.ne __sys_trace - cmp wscno, wsc_nr // check upper syscall limit - b.hs ni_sys - mask_nospec64 xscno, xsc_nr, x19 // enforce bounds for syscall number - ldr x16, [stbl, xscno, lsl #3] // address in the syscall table - blr x16 // call sys_* routine - b ret_fast_syscall -ni_sys: mov x0, sp - bl do_ni_syscall + mov w1, wscno + mov w2, wsc_nr + mov x3, stbl + bl invoke_syscall b ret_fast_syscall ENDPROC(el0_svc) @@ -1003,29 +998,18 @@ __sys_trace: bl syscall_trace_enter cmp w0, #NO_SYSCALL // skip the syscall? b.eq __sys_trace_return_skipped - mov wscno, w0 // syscall number (possibly new) - mov x1, sp // pointer to regs - cmp wscno, wsc_nr // check upper syscall limit - b.hs __ni_sys_trace - ldp x0, x1, [sp] // restore the syscall args - ldp x2, x3, [sp, #S_X2] - ldp x4, x5, [sp, #S_X4] - ldp x6, x7, [sp, #S_X6] - ldr x16, [stbl, xscno, lsl #3] // address in the syscall table - blr x16 // call sys_* routine -__sys_trace_return: - str x0, [sp, #S_X0] // save returned x0 + mov x0, sp + mov w1, wscno + mov w2, wsc_nr + mov x3, stbl + bl invoke_syscall + __sys_trace_return_skipped: mov x0, sp bl syscall_trace_exit b ret_to_user -__ni_sys_trace: - mov x0, sp - bl do_ni_syscall - b __sys_trace_return - .popsection // .entry.text #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c new file mode 100644 index 000000000000..93d36f22647e --- /dev/null +++ b/arch/arm64/kernel/syscall.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/errno.h> +#include <linux/nospec.h> +#include <linux/ptrace.h> +#include <linux/syscalls.h> + +#include <asm/syscall.h> + +long compat_arm_syscall(struct pt_regs *regs); + +asmlinkage long do_ni_syscall(struct pt_regs *regs) +{ +#ifdef CONFIG_COMPAT + long ret; + if (is_compat_task()) { + ret = compat_arm_syscall(regs); + if (ret != -ENOSYS) + return ret; + } +#endif + + return sys_ni_syscall(); +} + +static long __invoke_syscall(struct pt_regs *regs, syscall_fn_t syscall_fn) +{ + return syscall_fn(regs->regs[0], regs->regs[1], regs->regs[2], + regs->regs[3], regs->regs[4], regs->regs[5]); +} + +asmlinkage void invoke_syscall(struct pt_regs *regs, unsigned int scno, + unsigned int sc_nr, + const syscall_fn_t syscall_table[]) +{ + long ret; + + if (scno < sc_nr) { + syscall_fn_t syscall_fn; + syscall_fn = syscall_table[array_index_nospec(scno, sc_nr)]; + ret = __invoke_syscall(regs, syscall_fn); + } else { + ret = do_ni_syscall(regs); + } + + regs->regs[0] = ret; +} diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index c27292703bd1..039e9ff379cc 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -547,22 +547,6 @@ asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) do_undefinstr(regs); } -long compat_arm_syscall(struct pt_regs *regs); - -asmlinkage long do_ni_syscall(struct pt_regs *regs) -{ -#ifdef CONFIG_COMPAT - long ret; - if (is_compat_task()) { - ret = compat_arm_syscall(regs); - if (ret != -ENOSYS) - return ret; - } -#endif - - return sys_ni_syscall(); -} - static const char *esr_class_str[] = { [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized", |