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authorJan Beulich <jbeulich@novell.com>2006-12-07 02:14:02 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:02 +0100
commitbcddc0155f351ab3f06c6ede6d91fd399ef9e18f (patch)
treee3ba814c9cb319f6e486aea8e0fe537177f9594f
parent[PATCH] x86-64: dump_trace() atomicity fix (diff)
downloadlinux-bcddc0155f351ab3f06c6ede6d91fd399ef9e18f.tar.xz
linux-bcddc0155f351ab3f06c6ede6d91fd399ef9e18f.zip
[PATCH] x86-64: miscellaneous entry.S adjustments
This patch: - makes ret_from_sys_call no longer global (all external users were previously switched to use int_ret_from_sys_call) - adjusts placement of a CFI_{REMEMBER,RESTORE}_STATE pair to better fit logic flow - eliminates an unnecessary pair of CFI_{REMEMBER,RESTORE}_STATE - glues together function- and unwinder-wise the previously separate system_call and int_ret_from_sys_call function fragments Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de>
-rw-r--r--arch/x86_64/kernel/entry.S36
1 files changed, 6 insertions, 30 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 7d401b00d822..601d332c4b79 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -230,7 +230,6 @@ ENTRY(system_call)
CFI_REL_OFFSET rip,RIP-ARGOFFSET
GET_THREAD_INFO(%rcx)
testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%rcx)
- CFI_REMEMBER_STATE
jnz tracesys
cmpq $__NR_syscall_max,%rax
ja badsys
@@ -241,7 +240,6 @@ ENTRY(system_call)
* Syscall return path ending with SYSRET (fast path)
* Has incomplete stack frame and undefined top of stack.
*/
- .globl ret_from_sys_call
ret_from_sys_call:
movl $_TIF_ALLWORK_MASK,%edi
/* edi: flagmask */
@@ -251,8 +249,8 @@ sysret_check:
TRACE_IRQS_OFF
movl threadinfo_flags(%rcx),%edx
andl %edi,%edx
- CFI_REMEMBER_STATE
jnz sysret_careful
+ CFI_REMEMBER_STATE
/*
* sysretq will re-enable interrupts:
*/
@@ -265,10 +263,10 @@ sysret_check:
swapgs
sysretq
+ CFI_RESTORE_STATE
/* Handle reschedules */
/* edx: work, edi: workmask */
sysret_careful:
- CFI_RESTORE_STATE
bt $TIF_NEED_RESCHED,%edx
jnc sysret_signal
TRACE_IRQS_ON
@@ -306,7 +304,6 @@ badsys:
/* Do syscall tracing */
tracesys:
- CFI_RESTORE_STATE
SAVE_REST
movq $-ENOSYS,RAX(%rsp)
FIXUP_TOP_OF_STACK %rdi
@@ -322,32 +319,13 @@ tracesys:
call *sys_call_table(,%rax,8)
1: movq %rax,RAX-ARGOFFSET(%rsp)
/* Use IRET because user could have changed frame */
- jmp int_ret_from_sys_call
- CFI_ENDPROC
-END(system_call)
/*
* Syscall return path ending with IRET.
* Has correct top of stack, but partial stack frame.
- */
-ENTRY(int_ret_from_sys_call)
- CFI_STARTPROC simple
- CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,SS+8-ARGOFFSET
- /*CFI_REL_OFFSET ss,SS-ARGOFFSET*/
- CFI_REL_OFFSET rsp,RSP-ARGOFFSET
- /*CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/
- /*CFI_REL_OFFSET cs,CS-ARGOFFSET*/
- CFI_REL_OFFSET rip,RIP-ARGOFFSET
- CFI_REL_OFFSET rdx,RDX-ARGOFFSET
- CFI_REL_OFFSET rcx,RCX-ARGOFFSET
- CFI_REL_OFFSET rax,RAX-ARGOFFSET
- CFI_REL_OFFSET rdi,RDI-ARGOFFSET
- CFI_REL_OFFSET rsi,RSI-ARGOFFSET
- CFI_REL_OFFSET r8,R8-ARGOFFSET
- CFI_REL_OFFSET r9,R9-ARGOFFSET
- CFI_REL_OFFSET r10,R10-ARGOFFSET
- CFI_REL_OFFSET r11,R11-ARGOFFSET
+ */
+ .globl int_ret_from_sys_call
+int_ret_from_sys_call:
cli
TRACE_IRQS_OFF
testl $3,CS-ARGOFFSET(%rsp)
@@ -394,8 +372,6 @@ int_very_careful:
popq %rdi
CFI_ADJUST_CFA_OFFSET -8
andl $~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi
- cli
- TRACE_IRQS_OFF
jmp int_restore_rest
int_signal:
@@ -411,7 +387,7 @@ int_restore_rest:
TRACE_IRQS_OFF
jmp int_with_check
CFI_ENDPROC
-END(int_ret_from_sys_call)
+END(system_call)
/*
* Certain special system calls that need to save a complete full stack frame.