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Subject[PATCH 1/2] c6x: implement ret_from_kernel_execve() and switch to generic kernel_execve()
Date
Signed-off-by: Mark Salter <msalter@redhat.com>
---
arch/c6x/include/asm/unistd.h | 2 ++
arch/c6x/kernel/entry.S | 31 ++++++++++++++++++++++++-------
2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/arch/c6x/include/asm/unistd.h b/arch/c6x/include/asm/unistd.h
index 6d54ea4..1ce3a6f 100644
--- a/arch/c6x/include/asm/unistd.h
+++ b/arch/c6x/include/asm/unistd.h
@@ -16,6 +16,8 @@
#if !defined(_ASM_C6X_UNISTD_H) || defined(__SYSCALL)
#define _ASM_C6X_UNISTD_H

+#define __ARCH_WANT_KERNEL_EXECVE
+
/* Use the standard ABI for syscalls. */
#include <asm-generic/unistd.h>

diff --git a/arch/c6x/kernel/entry.S b/arch/c6x/kernel/entry.S
index 30b37e5..693002b 100644
--- a/arch/c6x/kernel/entry.S
+++ b/arch/c6x/kernel/entry.S
@@ -315,6 +315,30 @@ resume_userspace:
[A0] BNOP .S1 work_pending,5
BNOP .S1 restore_all,5

+ ;; extern void ret_from_kernel_execve(struct pt_regs *normal,
+ ;; struct pt_regs *new)
+ ;;
+ ;; Copy new regs to normal regs.
+ ;; Switch stack to normal regs and return to userspace.
+ ;;
+ENTRY(ret_from_kernel_execve)
+#ifdef CONFIG_C6X_BIG_KERNEL
+ MVKL .S2 memmove,B0
+ MVKH .S2 memmove,B0
+ B .S2 B0
+#else
+ B .S2 memmove
+#endif
+ ADDKPC .S2 0f,B3,2
+ MVK .S1 REGS__END,A6 ; sizeof(struct pt_regs)
+ SUB .L2X A4,8,B10 ; save new SP in callee-saved reg
+0:
+ BNOP .S2 resume_userspace,2
+ MV .S2 B10,SP ; switch stack
+ MVK .L2 0,B1
+ STW .D2T2 B1,*+SP(REGS__END+8) ; clear syscall flag
+ENDPROC(ret_from_kernel_execve)
+
;;
;; System call handling
;; B0 = syscall number (in sys_call_table)
@@ -593,13 +617,6 @@ ENTRY(sys_sigaltstack)
NOP 4
ENDPROC(sys_sigaltstack)

- ;; kernel_execve
-ENTRY(kernel_execve)
- MVK .S2 __NR_execve,B0
- SWE
- BNOP .S2 B3,5
-ENDPROC(kernel_execve)
-
;;
;; Special system calls
;; return address is in B3
--
1.7.9.1


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