@@ -30,21 +30,6 @@ saved_pc .req lr
.section .entry.text,"ax",%progbits
.align 5
-/*
- * As we will need to call out to some C functions,
- * we save r0 first to avoid needing to save registers around each C function
- * call.
- */
-ret_fast_syscall:
- UNWIND(.fnstart )
- UNWIND(.cantunwind )
- add sp, sp, #(S_R0 + S_OFF)
-#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
- bl stackleak_erase_on_task_stack
-#endif
- restore_user_regs
- UNWIND(.fnend )
-ENDPROC(ret_fast_syscall)
/*
* "slow" syscall return path. "why" tells us if this was a real syscall.
@@ -122,6 +107,8 @@ ENDPROC(vector_bhb_bpiall_swi)
#endif
.align 5
ENTRY(vector_swi)
+ UNWIND(.fnstart )
+ UNWIND(.cantunwind )
#ifdef CONFIG_CPU_V7M
v7m_exception_entry
#else
@@ -210,9 +197,9 @@ ENTRY(vector_swi)
mov r0, tbl
mov r2, scno @ syscall number from r7
bl invoke_syscall
- b ret_fast_syscall
-
#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
+ b 9002
+
/*
* We failed to handle a fault trying to access the page
* containing the swi instruction, but we're not really in a
@@ -225,8 +212,17 @@ ENTRY(vector_swi)
sub lr, saved_pc, #4
str lr, [sp, #S_PC]
get_thread_info tsk
- b ret_fast_syscall
+9002:
+ /* Exit !AEABI clause */
+#endif
+
+ /* Return from syscall */
+ add sp, sp, #(S_R0 + S_OFF)
+#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
+ bl stackleak_erase_on_task_stack
#endif
+ restore_user_regs
+ UNWIND(.fnend )
ENDPROC(vector_swi)
.ltorg
Since ret_fast_syscall() is now only called in two spots in vector_swi, we can inline the function into vector_swi, and skip the separate call, placing the code from ret_fast_syscall at the end of vector_swi and one of them inside an ifdef that gets compiled out for !EABI. TODO: is the UNWIND(.fnstart/.cantunwind/.fnend) really needed on vector_swi after this change or can I just drop it? I do not understand unwind well enough :/ Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- arch/arm/kernel/entry-common.S | 32 ++++++++++++++------------------ 1 file changed, 14 insertions(+), 18 deletions(-)