From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org, will.deacon@arm.com
Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com,
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: [PATCHv4 06/19] arm64: remove sigreturn wrappers
Date: Mon, 2 Jul 2018 12:04:02 +0100 [thread overview]
Message-ID: <20180702110415.10465-7-mark.rutland@arm.com> (raw)
In-Reply-To: <20180702110415.10465-1-mark.rutland@arm.com>
The arm64 sigreturn* syscall handlers are non-standard. Rather than
taking a number of user parameters in registers as per the AAPCS,
they expect the pt_regs as their sole argument.
To make this work, we override the syscall definitions to invoke
wrappers written in assembly, which mov the SP into x0, and branch to
their respective C functions.
On other architectures (such as x86), the sigreturn* functions take no
argument and instead use current_pt_regs() to acquire the user
registers. This requires less boilerplate code, and allows for other
features such as interposing C code in this path.
This patch takes the same approach for arm64.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tentatively-reviewed-by: Dave Martin <dave.martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
arch/arm64/include/asm/unistd32.h | 4 ++--
arch/arm64/kernel/entry.S | 8 --------
arch/arm64/kernel/entry32.S | 10 ----------
arch/arm64/kernel/signal.c | 3 ++-
arch/arm64/kernel/signal32.c | 6 ++++--
arch/arm64/kernel/sys.c | 3 +--
arch/arm64/kernel/sys32.c | 4 ++--
7 files changed, 11 insertions(+), 27 deletions(-)
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index ef292160748c..ab95554b1734 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -260,7 +260,7 @@ __SYSCALL(117, sys_ni_syscall)
#define __NR_fsync 118
__SYSCALL(__NR_fsync, sys_fsync)
#define __NR_sigreturn 119
-__SYSCALL(__NR_sigreturn, compat_sys_sigreturn_wrapper)
+__SYSCALL(__NR_sigreturn, compat_sys_sigreturn)
#define __NR_clone 120
__SYSCALL(__NR_clone, sys_clone)
#define __NR_setdomainname 121
@@ -368,7 +368,7 @@ __SYSCALL(__NR_getresgid, sys_getresgid16)
#define __NR_prctl 172
__SYSCALL(__NR_prctl, sys_prctl)
#define __NR_rt_sigreturn 173
-__SYSCALL(__NR_rt_sigreturn, compat_sys_rt_sigreturn_wrapper)
+__SYSCALL(__NR_rt_sigreturn, compat_sys_rt_sigreturn)
#define __NR_rt_sigaction 174
__SYSCALL(__NR_rt_sigaction, compat_sys_rt_sigaction)
#define __NR_rt_sigprocmask 175
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 28ad8799406f..62f2876f9c63 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1138,14 +1138,6 @@ __entry_tramp_data_start:
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
/*
- * Special system call wrappers.
- */
-ENTRY(sys_rt_sigreturn_wrapper)
- mov x0, sp
- b sys_rt_sigreturn
-ENDPROC(sys_rt_sigreturn_wrapper)
-
-/*
* Register switch for AArch64. The callee-saved registers need to be saved
* and restored. On entry:
* x0 = previous task_struct (must be preserved across the switch)
diff --git a/arch/arm64/kernel/entry32.S b/arch/arm64/kernel/entry32.S
index f332d5d1f6b4..f9461696dde4 100644
--- a/arch/arm64/kernel/entry32.S
+++ b/arch/arm64/kernel/entry32.S
@@ -30,16 +30,6 @@
* System call wrappers for the AArch32 compatibility layer.
*/
-ENTRY(compat_sys_sigreturn_wrapper)
- mov x0, sp
- b compat_sys_sigreturn
-ENDPROC(compat_sys_sigreturn_wrapper)
-
-ENTRY(compat_sys_rt_sigreturn_wrapper)
- mov x0, sp
- b compat_sys_rt_sigreturn
-ENDPROC(compat_sys_rt_sigreturn_wrapper)
-
ENTRY(compat_sys_statfs64_wrapper)
mov w3, #84
cmp w1, #88
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 70287634706e..f03e664f773f 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -539,8 +539,9 @@ static int restore_sigframe(struct pt_regs *regs,
return err;
}
-asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+asmlinkage long sys_rt_sigreturn(void)
{
+ struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame;
/* Always make any pending restarted system calls return -EINTR */
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index 77b91f478995..cb10588a7cb2 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c
@@ -282,8 +282,9 @@ static int compat_restore_sigframe(struct pt_regs *regs,
return err;
}
-asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
+asmlinkage int compat_sys_sigreturn(void)
{
+ struct pt_regs *regs = current_pt_regs();
struct compat_sigframe __user *frame;
/* Always make any pending restarted system calls return -EINTR */
@@ -312,8 +313,9 @@ asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
return 0;
}
-asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
+asmlinkage int compat_sys_rt_sigreturn(void)
{
+ struct pt_regs *regs = current_pt_regs();
struct compat_rt_sigframe __user *frame;
/* Always make any pending restarted system calls return -EINTR */
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 72981bae10eb..31045f3fed92 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -48,8 +48,7 @@ SYSCALL_DEFINE1(arm64_personality, unsigned int, personality)
/*
* Wrappers to pass the pt_regs argument.
*/
-asmlinkage long sys_rt_sigreturn_wrapper(void);
-#define sys_rt_sigreturn sys_rt_sigreturn_wrapper
+asmlinkage long sys_rt_sigreturn(void);
#define sys_personality sys_arm64_personality
#undef __SYSCALL
diff --git a/arch/arm64/kernel/sys32.c b/arch/arm64/kernel/sys32.c
index a40b1343b819..1ef103c95410 100644
--- a/arch/arm64/kernel/sys32.c
+++ b/arch/arm64/kernel/sys32.c
@@ -25,8 +25,8 @@
#include <linux/compiler.h>
#include <linux/syscalls.h>
-asmlinkage long compat_sys_sigreturn_wrapper(void);
-asmlinkage long compat_sys_rt_sigreturn_wrapper(void);
+asmlinkage long compat_sys_sigreturn(void);
+asmlinkage long compat_sys_rt_sigreturn(void);
asmlinkage long compat_sys_statfs64_wrapper(void);
asmlinkage long compat_sys_fstatfs64_wrapper(void);
asmlinkage long compat_sys_pread64_wrapper(void);
--
2.11.0
next prev parent reply other threads:[~2018-07-02 11:08 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-02 11:03 [PATCHv4 00/19] arm64: invoke syscalls with pt_regs Mark Rutland
2018-07-02 11:03 ` [PATCHv4 01/19] arm64: consistently use unsigned long for thread flags Mark Rutland
2018-07-02 11:03 ` [PATCHv4 02/19] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> Mark Rutland
2018-07-02 11:03 ` [PATCHv4 03/19] arm64: kill config_sctlr_el1() Mark Rutland
2018-07-02 11:04 ` [PATCHv4 04/19] arm64: kill change_cpacr() Mark Rutland
2018-07-02 11:04 ` [PATCHv4 05/19] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> Mark Rutland
2018-07-02 11:04 ` Mark Rutland [this message]
2018-07-02 11:04 ` [PATCHv4 07/19] arm64: convert raw syscall invocation to C Mark Rutland
2018-07-02 11:04 ` [PATCHv4 08/19] arm64: convert syscall trace logic " Mark Rutland
2018-07-02 11:04 ` [PATCHv4 09/19] arm64: convert native/compat syscall entry " Mark Rutland
2018-07-02 11:04 ` [PATCHv4 10/19] arm64: don't restore GPRs when context tracking Mark Rutland
2018-07-02 11:04 ` [PATCHv4 11/19] arm64: don't reload GPRs after apply_ssbd Mark Rutland
2018-07-06 16:38 ` Will Deacon
2018-07-09 14:21 ` Mark Rutland
2018-07-10 10:37 ` Dave Martin
2018-07-10 17:33 ` Will Deacon
2018-07-11 9:46 ` Mark Rutland
2018-07-02 11:04 ` [PATCHv4 12/19] arm64: zero GPRs upon entry from EL0 Mark Rutland
2018-07-02 11:04 ` [PATCHv4 13/19] kernel: add ksys_personality() Mark Rutland
2018-07-02 11:04 ` [PATCHv4 14/19] kernel: add kcompat_sys_{f,}statfs64() Mark Rutland
2018-07-02 11:04 ` [PATCHv4 15/19] arm64: remove in-kernel call to sys_personality() Mark Rutland
2018-07-02 11:04 ` [PATCHv4 16/19] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn Mark Rutland
2018-07-02 11:04 ` [PATCHv4 17/19] arm64: use SYSCALL_DEFINE6() for mmap Mark Rutland
2018-07-02 11:04 ` [PATCHv4 18/19] arm64: convert compat wrappers to C Mark Rutland
2018-07-02 11:04 ` [PATCHv4 19/19] arm64: implement syscall wrappers Mark Rutland
2018-07-06 16:42 ` [PATCHv4 00/19] arm64: invoke syscalls with pt_regs Will Deacon
2018-07-10 10:39 ` Will Deacon
2018-07-11 10:47 ` Mark Rutland
2018-07-11 12:27 ` Will Deacon
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