From: Mark Rutland <mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will.deacon@arm.com Cc: dave.martin@arm.com, hch@infradead.org, james.morse@arm.com, linux@dominikbrodowski.net, linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, viro@zeniv.linux.org.uk Subject: [PATCHv3 08/19] arm64: convert raw syscall invocation to C Date: Mon, 18 Jun 2018 13:02:59 +0100 [thread overview] Message-ID: <20180618120310.39527-9-mark.rutland@arm.com> (raw) In-Reply-To: <20180618120310.39527-1-mark.rutland@arm.com> As a first step towards invoking syscalls with a pt_regs argument, convert the raw syscall invocation logic to C. We end up with a bit more register shuffling, but the unified invocation logic means we can unify the tracing paths, too. Previously, assembly had to open-code calls to ni_sys() when the system call number was out-of-bounds for the relevant syscall table. This case is now handled by invoke_syscall(), and the assembly no longer need to handle this case explicitly. This allows the tracing paths to be simplfiied and unified, as we no longer need the __ni_sys_trace path and the __sys_trace_return label. This only converts the invocation of the syscall. The rest of the syscall triage and tracing is left in assembly for now, and will be converted in subsequent patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/Makefile | 3 ++- arch/arm64/kernel/entry.S | 36 ++++++++++-------------------------- arch/arm64/kernel/syscall.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+), 27 deletions(-) create mode 100644 arch/arm64/kernel/syscall.c 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 62f2876f9c63..c0392f78e392 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 ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK cbnz x2, ret_fast_syscall_trace @@ -976,15 +975,11 @@ 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) @@ -1001,29 +996,18 @@ __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..b463b962d597 --- /dev/null +++ b/arch/arm64/kernel/syscall.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/nospec.h> +#include <linux/ptrace.h> + +long do_ni_syscall(struct pt_regs *regs); + +typedef long (*syscall_fn_t)(unsigned long, unsigned long, + unsigned long, unsigned long, + unsigned long, unsigned long); + +static void __invoke_syscall(struct pt_regs *regs, syscall_fn_t syscall_fn) +{ + regs->regs[0] = 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, + syscall_fn_t syscall_table[]) +{ + if (scno < sc_nr) { + syscall_fn_t syscall_fn; + syscall_fn = syscall_table[array_index_nospec(scno, sc_nr)]; + __invoke_syscall(regs, syscall_fn); + } else { + regs->regs[0] = do_ni_syscall(regs); + } +} -- 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: mark.rutland@arm.com (Mark Rutland) To: linux-arm-kernel@lists.infradead.org Subject: [PATCHv3 08/19] arm64: convert raw syscall invocation to C Date: Mon, 18 Jun 2018 13:02:59 +0100 [thread overview] Message-ID: <20180618120310.39527-9-mark.rutland@arm.com> (raw) In-Reply-To: <20180618120310.39527-1-mark.rutland@arm.com> As a first step towards invoking syscalls with a pt_regs argument, convert the raw syscall invocation logic to C. We end up with a bit more register shuffling, but the unified invocation logic means we can unify the tracing paths, too. Previously, assembly had to open-code calls to ni_sys() when the system call number was out-of-bounds for the relevant syscall table. This case is now handled by invoke_syscall(), and the assembly no longer need to handle this case explicitly. This allows the tracing paths to be simplfiied and unified, as we no longer need the __ni_sys_trace path and the __sys_trace_return label. This only converts the invocation of the syscall. The rest of the syscall triage and tracing is left in assembly for now, and will be converted in subsequent patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/Makefile | 3 ++- arch/arm64/kernel/entry.S | 36 ++++++++++-------------------------- arch/arm64/kernel/syscall.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+), 27 deletions(-) create mode 100644 arch/arm64/kernel/syscall.c 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 62f2876f9c63..c0392f78e392 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 ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK cbnz x2, ret_fast_syscall_trace @@ -976,15 +975,11 @@ 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) @@ -1001,29 +996,18 @@ __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..b463b962d597 --- /dev/null +++ b/arch/arm64/kernel/syscall.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/nospec.h> +#include <linux/ptrace.h> + +long do_ni_syscall(struct pt_regs *regs); + +typedef long (*syscall_fn_t)(unsigned long, unsigned long, + unsigned long, unsigned long, + unsigned long, unsigned long); + +static void __invoke_syscall(struct pt_regs *regs, syscall_fn_t syscall_fn) +{ + regs->regs[0] = 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, + syscall_fn_t syscall_table[]) +{ + if (scno < sc_nr) { + syscall_fn_t syscall_fn; + syscall_fn = syscall_table[array_index_nospec(scno, sc_nr)]; + __invoke_syscall(regs, syscall_fn); + } else { + regs->regs[0] = do_ni_syscall(regs); + } +} -- 2.11.0
next prev parent reply other threads:[~2018-06-18 12:03 UTC|newest] Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-06-18 12:02 [PATCHv3 00/19] arm64: invoke syscalls with pt_regs Mark Rutland 2018-06-18 12:02 ` Mark Rutland 2018-06-18 12:02 ` [PATCHv3 01/19] arm64: consistently use unsigned long for thread flags Mark Rutland 2018-06-18 12:02 ` Mark Rutland 2018-06-19 10:49 ` Catalin Marinas 2018-06-19 10:49 ` Catalin Marinas 2018-06-19 11:19 ` Mark Rutland 2018-06-19 11:19 ` Mark Rutland 2018-06-18 12:02 ` [PATCHv3 02/19] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> Mark Rutland 2018-06-18 12:02 ` [PATCHv3 02/19] arm64: move SCTLR_EL{1, 2} " Mark Rutland 2018-06-19 11:02 ` Catalin Marinas 2018-06-19 11:02 ` Catalin Marinas 2018-06-19 11:48 ` [PATCHv3 02/19] arm64: move SCTLR_EL{1,2} " Mark Rutland 2018-06-19 11:48 ` Mark Rutland 2018-06-18 12:02 ` [PATCHv3 03/19] arm64: introduce sysreg_clear_set() Mark Rutland 2018-06-18 12:02 ` Mark Rutland 2018-06-19 11:44 ` Catalin Marinas 2018-06-19 11:44 ` Catalin Marinas 2018-06-19 11:47 ` Marc Zyngier 2018-06-19 11:47 ` Marc Zyngier 2018-06-18 12:02 ` [PATCHv3 04/19] arm64: kill config_sctlr_el1() Mark Rutland 2018-06-18 12:02 ` Mark Rutland 2018-06-19 11:44 ` Catalin Marinas 2018-06-19 11:44 ` Catalin Marinas 2018-06-18 12:02 ` [PATCHv3 05/19] arm64: kill change_cpacr() Mark Rutland 2018-06-18 12:02 ` Mark Rutland 2018-06-19 11:45 ` Catalin Marinas 2018-06-19 11:45 ` Catalin Marinas 2018-06-18 12:02 ` [PATCHv3 06/19] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> Mark Rutland 2018-06-18 12:02 ` [PATCHv3 06/19] arm64: move sve_user_{enable, disable} " Mark Rutland 2018-06-19 12:00 ` Catalin Marinas 2018-06-19 12:00 ` Catalin Marinas 2018-06-19 12:19 ` Dave Martin 2018-06-19 12:19 ` Dave Martin 2018-06-18 12:02 ` [PATCHv3 07/19] arm64: remove sigreturn wrappers Mark Rutland 2018-06-18 12:02 ` Mark Rutland 2018-06-19 12:47 ` Catalin Marinas 2018-06-19 12:47 ` Catalin Marinas 2018-06-18 12:02 ` Mark Rutland [this message] 2018-06-18 12:02 ` [PATCHv3 08/19] arm64: convert raw syscall invocation to C Mark Rutland 2018-06-19 13:33 ` Catalin Marinas 2018-06-19 13:33 ` Catalin Marinas 2018-06-19 14:21 ` Catalin Marinas 2018-06-19 14:21 ` Catalin Marinas 2018-06-19 14:48 ` Mark Rutland 2018-06-19 14:48 ` Mark Rutland 2018-06-19 14:55 ` Catalin Marinas 2018-06-19 14:55 ` Catalin Marinas 2018-06-19 14:58 ` Mark Rutland 2018-06-19 14:58 ` Mark Rutland 2018-06-18 12:03 ` [PATCHv3 09/19] arm64: convert syscall trace logic " Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 14:32 ` Catalin Marinas 2018-06-19 14:32 ` Catalin Marinas 2018-06-19 15:14 ` Mark Rutland 2018-06-19 15:14 ` Mark Rutland 2018-06-18 12:03 ` [PATCHv3 10/19] arm64: convert native/compat syscall entry " Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 12:18 ` Dave Martin 2018-06-19 12:18 ` Dave Martin 2018-06-19 13:15 ` Mark Rutland 2018-06-19 13:15 ` Mark Rutland 2018-06-20 9:21 ` Dave Martin 2018-06-20 9:21 ` Dave Martin 2018-06-19 15:20 ` Catalin Marinas 2018-06-19 15:20 ` Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 11/19] arm64: don't reload GPRs after apply_ssbd Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:23 ` Catalin Marinas 2018-06-19 15:23 ` Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 12/19] arm64: zero GPRs upon entry from EL0 Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:24 ` Catalin Marinas 2018-06-19 15:24 ` Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 13/19] kernel: add ksys_personality() Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:45 ` Catalin Marinas 2018-06-19 15:45 ` Catalin Marinas 2018-06-19 15:53 ` Mark Rutland 2018-06-19 15:53 ` Mark Rutland 2018-06-18 12:03 ` [PATCHv3 14/19] kernel: add kcompat_sys_{f,}statfs64() Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-18 12:03 ` [PATCHv3 15/19] arm64: remove in-kernel call to sys_personality() Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:46 ` Catalin Marinas 2018-06-19 15:46 ` Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 16/19] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:48 ` Catalin Marinas 2018-06-19 15:48 ` [PATCHv3 16/19] arm64: use {COMPAT, }SYSCALL_DEFINE0 " Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 17/19] arm64: use SYSCALL_DEFINE6() for mmap Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:50 ` Catalin Marinas 2018-06-19 15:50 ` Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 18/19] arm64: convert compat wrappers to C Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 15:51 ` Catalin Marinas 2018-06-19 15:51 ` Catalin Marinas 2018-06-18 12:03 ` [PATCHv3 19/19] arm64: implement syscall wrappers Mark Rutland 2018-06-18 12:03 ` Mark Rutland 2018-06-19 16:13 ` Catalin Marinas 2018-06-19 16:13 ` Catalin Marinas 2018-06-19 15:38 ` [PATCHv3 00/19] arm64: invoke syscalls with pt_regs Mark Rutland 2018-06-19 15:38 ` Mark Rutland 2018-06-19 16:14 ` Catalin Marinas 2018-06-19 16:14 ` Catalin Marinas
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