From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com,
dave.martin@arm.com, 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, will.deacon@arm.com
Subject: [PATCH 08/18] arm64: convert raw syscall invocation to C
Date: Mon, 14 May 2018 10:46:30 +0100 [thread overview]
Message-ID: <20180514094640.27569-9-mark.rutland@arm.com> (raw)
In-Reply-To: <20180514094640.27569-1-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.
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 | 29 +++++++++++++++++++++++++++++
3 files changed, 41 insertions(+), 27 deletions(-)
create mode 100644 arch/arm64/kernel/syscall.c
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index bf825f38d206..c22e8ace5ea3 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 08ea3cbfb08f..d6e057500eaf 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -873,7 +873,6 @@ 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
@@ -946,15 +945,11 @@ 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)
@@ -971,29 +966,18 @@ __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..58d7569f47df
--- /dev/null
+++ b/arch/arm64/kernel/syscall.c
@@ -0,0 +1,29 @@
+// 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, int scno, 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:[~2018-05-14 9:47 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-14 9:46 [PATCH 00/18] arm64: invoke syscalls with pt_regs Mark Rutland
2018-05-14 9:46 ` [PATCH 01/18] arm64: consistently use unsigned long for thread flags Mark Rutland
2018-05-14 9:57 ` Dave Martin
2018-05-14 9:46 ` [PATCH 02/18] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> Mark Rutland
2018-05-14 10:00 ` Dave Martin
2018-05-14 10:08 ` Mark Rutland
2018-05-14 11:20 ` Dave Martin
2018-05-14 11:56 ` Robin Murphy
2018-05-14 12:06 ` Mark Rutland
2018-05-14 12:41 ` Dave Martin
2018-05-14 13:10 ` Mark Rutland
2018-05-14 9:46 ` [PATCH 03/18] arm64: introduce sysreg_clear_set() Mark Rutland
2018-05-14 10:04 ` Dave Martin
2018-05-14 9:46 ` [PATCH 04/18] arm64: kill config_sctlr_el1() Mark Rutland
2018-05-14 10:05 ` Dave Martin
2018-05-14 9:46 ` [PATCH 05/18] arm64: kill change_cpacr() Mark Rutland
2018-05-14 10:06 ` Dave Martin
2018-05-14 9:46 ` [PATCH 06/18] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> Mark Rutland
2018-05-14 11:06 ` [PATCH 06/18] arm64: move sve_user_{enable, disable} " Dave Martin
2018-05-15 10:39 ` Mark Rutland
2018-05-15 12:19 ` Dave Martin
2018-05-15 16:33 ` Mark Rutland
2018-05-16 9:01 ` Dave Martin
2018-06-01 10:29 ` Mark Rutland
2018-06-01 10:42 ` Dave Martin
2018-05-14 9:46 ` [PATCH 07/18] arm64: remove sigreturn wrappers Mark Rutland
2018-05-14 11:07 ` Dave Martin
2018-05-14 9:46 ` Mark Rutland [this message]
2018-05-14 11:07 ` [PATCH 08/18] arm64: convert raw syscall invocation to C Dave Martin
2018-05-14 11:41 ` Mark Rutland
2018-05-14 12:53 ` Dave Martin
2018-05-14 20:24 ` Dominik Brodowski
2018-05-15 8:22 ` Mark Rutland
2018-05-15 10:01 ` Dominik Brodowski
2018-05-15 10:13 ` Mark Rutland
2018-05-14 18:00 ` Dominik Brodowski
2018-05-15 8:18 ` Mark Rutland
2018-05-14 9:46 ` [PATCH 09/18] arm64: convert syscall trace logic " Mark Rutland
2018-05-14 9:46 ` [PATCH 10/18] arm64: convert native/compat syscall entry " Mark Rutland
2018-05-14 11:07 ` Dave Martin
2018-05-14 11:58 ` Mark Rutland
2018-05-14 14:43 ` Dave Martin
2018-05-14 15:01 ` Mark Rutland
2018-05-14 9:46 ` [PATCH 11/18] arm64: zero GPRs upon entry from EL0 Mark Rutland
2018-05-14 11:07 ` Dave Martin
2018-05-14 9:46 ` [PATCH 12/18] kernel: add ksys_personality() Mark Rutland
2018-05-14 11:08 ` Dave Martin
2018-05-14 12:07 ` Christoph Hellwig
2018-05-15 9:56 ` Mark Rutland
2018-05-14 9:46 ` [PATCH 13/18] kernel: add kcompat_sys_{f,}statfs64() Mark Rutland
2018-05-14 17:14 ` Mark Rutland
2018-05-14 20:34 ` Dominik Brodowski
2018-05-15 9:53 ` Mark Rutland
2018-05-15 9:58 ` Dominik Brodowski
2018-05-14 9:46 ` [PATCH 14/18] arm64: remove in-kernel call to sys_personality() Mark Rutland
2018-05-14 9:46 ` [PATCH 15/18] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn Mark Rutland
2018-05-14 9:46 ` [PATCH 16/18] arm64: use SYSCALL_DEFINE6() for mmap Mark Rutland
2018-05-14 9:46 ` [PATCH 17/18] arm64: convert compat wrappers to C Mark Rutland
2018-05-14 12:10 ` Christoph Hellwig
2018-05-14 12:43 ` Mark Rutland
2018-05-14 9:46 ` [PATCH 18/18] arm64: implement syscall wrappers Mark Rutland
2018-05-14 20:57 ` Dominik Brodowski
2018-05-15 8:37 ` Mark Rutland
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