* [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue
@ 2015-04-07 20:43 Denys Vlasenko
2015-04-07 20:43 ` [PATCH 2/8] x86/asm/entry/64: Move stub_x32_execve[at] closer to stub_execveat Denys Vlasenko
` (7 more replies)
0 siblings, 8 replies; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
Similarly to stub_execve, we can reuse the epilogue in stub_rt_sigreturn
and stub_x32_rt_sigreturn.
Add a comment explaining why we can't eliminage SAVE_EXTRA_REGS here.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 15261ba..994f3cb 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -450,12 +450,21 @@ END(stub_execveat)
*/
ENTRY(stub_rt_sigreturn)
CFI_STARTPROC
- addq $8, %rsp
- DEFAULT_FRAME 0
- SAVE_EXTRA_REGS
+ DEFAULT_FRAME 0, 8
+ /*
+ * SAVE_EXTRA_REGS result is not normally needed:
+ * sigreturn overwrites all pt_regs->GPREGS.
+ * But sigreturn can fail (!), and there is no easy way to detect that.
+ * To make sure RESTORE_EXTRA_REGS doesn't restore garbage on error,
+ * we SAVE_EXTRA_REGS here.
+ */
+ SAVE_EXTRA_REGS 8
call sys_rt_sigreturn
- movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
+return_from_stub:
+ addq $8, %rsp
+ CFI_ADJUST_CFA_OFFSET -8
RESTORE_EXTRA_REGS
+ movq %rax,RAX(%rsp)
jmp int_ret_from_sys_call
CFI_ENDPROC
END(stub_rt_sigreturn)
@@ -463,13 +472,10 @@ END(stub_rt_sigreturn)
#ifdef CONFIG_X86_X32_ABI
ENTRY(stub_x32_rt_sigreturn)
CFI_STARTPROC
- addq $8, %rsp
- DEFAULT_FRAME 0
- SAVE_EXTRA_REGS
+ DEFAULT_FRAME 0, 8
+ SAVE_EXTRA_REGS 8
call sys32_x32_rt_sigreturn
- movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_x32_rt_sigreturn)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 2/8] x86/asm/entry/64: Move stub_x32_execve[at] closer to stub_execveat
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-09 9:02 ` [tip:x86/asm] x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat() tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too Denys Vlasenko
` (6 subsequent siblings)
7 siblings, 1 reply; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
This is a preparatory patch for moving stub32_execve[at] to this file.
It makes sense to have all execve stubs in one place, so that they can reuse code.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 994f3cb..1b0793c 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -444,6 +444,23 @@ ENTRY(stub_execveat)
CFI_ENDPROC
END(stub_execveat)
+#ifdef CONFIG_X86_X32_ABI
+ENTRY(stub_x32_execve)
+ CFI_STARTPROC
+ DEFAULT_FRAME 0, 8
+ call compat_sys_execve
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub_x32_execve)
+ENTRY(stub_x32_execveat)
+ CFI_STARTPROC
+ DEFAULT_FRAME 0, 8
+ call compat_sys_execveat
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub_x32_execveat)
+#endif
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
@@ -478,23 +495,6 @@ ENTRY(stub_x32_rt_sigreturn)
jmp return_from_stub
CFI_ENDPROC
END(stub_x32_rt_sigreturn)
-
-ENTRY(stub_x32_execve)
- CFI_STARTPROC
- DEFAULT_FRAME 0, 8
- call compat_sys_execve
- jmp return_from_execve
- CFI_ENDPROC
-END(stub_x32_execve)
-
-ENTRY(stub_x32_execveat)
- CFI_STARTPROC
- DEFAULT_FRAME 0, 8
- call compat_sys_execveat
- jmp return_from_execve
- CFI_ENDPROC
-END(stub_x32_execveat)
-
#endif
/*
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
2015-04-07 20:43 ` [PATCH 2/8] x86/asm/entry/64: Move stub_x32_execve[at] closer to stub_execveat Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-08 2:39 ` Brian Gerst
2015-04-09 9:02 ` [tip:x86/asm] x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 4/8] x86/asm/entry/64: optimize [v]fork/clone stubs Denys Vlasenko
` (5 subsequent siblings)
7 siblings, 2 replies; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
The change which affected how execve clears EXTRA_REGS missed
32-bit execve syscalls.
Fix this by using 64-bit execve stub epilogue for them too.
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/ia32/ia32entry.S | 2 --
arch/x86/kernel/entry_64.S | 15 +++++++++++++++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 5d8f987..a821b1c 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -571,8 +571,6 @@ GLOBAL(\label)
PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
PTREGSCALL stub32_sigreturn, sys32_sigreturn
- PTREGSCALL stub32_execve, compat_sys_execve
- PTREGSCALL stub32_execveat, compat_sys_execveat
PTREGSCALL stub32_fork, sys_fork
PTREGSCALL stub32_vfork, sys_vfork
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 1b0793c..8e3ba38 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -461,6 +461,21 @@ ENTRY(stub_x32_execveat)
END(stub_x32_execveat)
#endif
+#ifdef CONFIG_IA32_EMULATION
+ENTRY(stub32_execve)
+ CFI_STARTPROC
+ call compat_sys_execve
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub32_execve)
+ENTRY(stub32_execveat)
+ CFI_STARTPROC
+ call compat_sys_execveat
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub32_execveat)
+#endif
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 4/8] x86/asm/entry/64: optimize [v]fork/clone stubs
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
2015-04-07 20:43 ` [PATCH 2/8] x86/asm/entry/64: Move stub_x32_execve[at] closer to stub_execveat Denys Vlasenko
2015-04-07 20:43 ` [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-09 9:02 ` [tip:x86/asm] x86/asm/entry/64: Optimize " tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 5/8] x86/asm/entry/64: remove a redundant jump Denys Vlasenko
` (4 subsequent siblings)
7 siblings, 1 reply; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
Replace "call func; ret" with "jmp func".
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 8e3ba38..6ad30a7 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -407,8 +407,7 @@ ENTRY(stub_\func)
CFI_STARTPROC
DEFAULT_FRAME 0, 8 /* offset 8: return address */
SAVE_EXTRA_REGS 8
- call sys_\func
- ret
+ jmp sys_\func
CFI_ENDPROC
END(stub_\func)
.endm
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 5/8] x86/asm/entry/64: remove a redundant jump
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
` (2 preceding siblings ...)
2015-04-07 20:43 ` [PATCH 4/8] x86/asm/entry/64: optimize [v]fork/clone stubs Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-09 9:03 ` [tip:x86/asm] x86/asm/entry/64: Remove " tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 6/8] x86/asm/entry/64: simplify jumps in ret_from_fork Denys Vlasenko
` (3 subsequent siblings)
7 siblings, 1 reply; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
Jumping to the very next instruction is not very useful:
jmp label
label:
Removing the jump.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 6ad30a7..7d4c7c6 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1455,7 +1455,6 @@ ENTRY(nmi)
/* If it is below the NMI stack, it is a normal NMI */
jb first_nmi
/* Ah, it is within the NMI stack, treat it as nested */
- jmp nested_nmi
CFI_REMEMBER_STATE
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 6/8] x86/asm/entry/64: simplify jumps in ret_from_fork
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
` (3 preceding siblings ...)
2015-04-07 20:43 ` [PATCH 5/8] x86/asm/entry/64: remove a redundant jump Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-09 9:03 ` [tip:x86/asm] x86/asm/entry/64: Simplify " tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 7/8] x86/asm/entry/64: Remove GET_THREAD_INFO " Denys Vlasenko
` (2 subsequent siblings)
7 siblings, 1 reply; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
Replace
test
jz 1f
jmp label
1:
with
test
jnz label
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 7d4c7c6..9915897 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -531,18 +531,18 @@ ENTRY(ret_from_fork)
RESTORE_EXTRA_REGS
testl $3,CS(%rsp) # from kernel_thread?
- jz 1f
/*
* By the time we get here, we have no idea whether our pt_regs,
* ti flags, and ti status came from the 64-bit SYSCALL fast path,
* the slow path, or one of the ia32entry paths.
- * Use int_ret_from_sys_call to return, since it can safely handle
+ * Use IRET code path to return, since it can safely handle
* all of the above.
*/
- jmp int_ret_from_sys_call
+ jnz int_ret_from_sys_call
-1:
+ /* We came from kernel_thread */
+ /* nb: we depend on RESTORE_EXTRA_REGS above */
movq %rbp, %rdi
call *%rbx
movl $0, RAX(%rsp)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 7/8] x86/asm/entry/64: Remove GET_THREAD_INFO in ret_from_fork
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
` (4 preceding siblings ...)
2015-04-07 20:43 ` [PATCH 6/8] x86/asm/entry/64: simplify jumps in ret_from_fork Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-09 9:03 ` [tip:x86/asm] x86/asm/entry/64: Remove GET_THREAD_INFO() " tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 8/8] x86/asm/entry/64: Reduce padding in execve stubs Denys Vlasenko
2015-04-09 9:01 ` [tip:x86/asm] x86/asm/entry/64: Use common code for rt_sigreturn( ) epilogue tip-bot for Denys Vlasenko
7 siblings, 1 reply; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
It used to be used to check for _TIF_IA32, but the check has been removed.
Remove GET_THREAD_INFO too.
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 9915897..05224d4 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -526,8 +526,6 @@ ENTRY(ret_from_fork)
call schedule_tail # rdi: 'prev' task parameter
- GET_THREAD_INFO(%rcx)
-
RESTORE_EXTRA_REGS
testl $3,CS(%rsp) # from kernel_thread?
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH 8/8] x86/asm/entry/64: Reduce padding in execve stubs
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
` (5 preceding siblings ...)
2015-04-07 20:43 ` [PATCH 7/8] x86/asm/entry/64: Remove GET_THREAD_INFO " Denys Vlasenko
@ 2015-04-07 20:43 ` Denys Vlasenko
2015-04-09 9:04 ` [tip:x86/asm] " tip-bot for Denys Vlasenko
2015-04-09 9:01 ` [tip:x86/asm] x86/asm/entry/64: Use common code for rt_sigreturn( ) epilogue tip-bot for Denys Vlasenko
7 siblings, 1 reply; 17+ messages in thread
From: Denys Vlasenko @ 2015-04-07 20:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
x86, linux-kernel
execve stubs are 7 bytes only. Padding them to 16 bytes is a waste.
text data bss dec hex filename
12594 0 0 12594 3132 entry_64.o.before
12530 0 0 12530 30f2 entry_64.o
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 05224d4..2aa3eca 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -434,8 +434,12 @@ return_from_execve:
jmp int_ret_from_sys_call
CFI_ENDPROC
END(stub_execve)
-
-ENTRY(stub_execveat)
+/*
+ * Remaining execve stubs are only 7 bytes long.
+ * ENTRY() often aligns to 16 bytes, which in this case has no benefits.
+ */
+ .align 8
+GLOBAL(stub_execveat)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call sys_execveat
@@ -444,14 +448,16 @@ ENTRY(stub_execveat)
END(stub_execveat)
#ifdef CONFIG_X86_X32_ABI
-ENTRY(stub_x32_execve)
+ .align 8
+GLOBAL(stub_x32_execve)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call compat_sys_execve
jmp return_from_execve
CFI_ENDPROC
END(stub_x32_execve)
-ENTRY(stub_x32_execveat)
+ .align 8
+GLOBAL(stub_x32_execveat)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call compat_sys_execveat
@@ -461,13 +467,15 @@ END(stub_x32_execveat)
#endif
#ifdef CONFIG_IA32_EMULATION
-ENTRY(stub32_execve)
+ .align 8
+GLOBAL(stub32_execve)
CFI_STARTPROC
call compat_sys_execve
jmp return_from_execve
CFI_ENDPROC
END(stub32_execve)
-ENTRY(stub32_execveat)
+ .align 8
+GLOBAL(stub32_execveat)
CFI_STARTPROC
call compat_sys_execveat
jmp return_from_execve
--
1.8.1.4
^ permalink raw reply related [flat|nested] 17+ messages in thread
* Re: [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too
2015-04-07 20:43 ` [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too Denys Vlasenko
@ 2015-04-08 2:39 ` Brian Gerst
2015-04-09 9:02 ` [tip:x86/asm] x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too tip-bot for Denys Vlasenko
1 sibling, 0 replies; 17+ messages in thread
From: Brian Gerst @ 2015-04-08 2:39 UTC (permalink / raw)
To: Denys Vlasenko
Cc: Ingo Molnar, Linus Torvalds, Steven Rostedt, Borislav Petkov,
H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
the arch/x86 maintainers, Linux Kernel Mailing List
On Tue, Apr 7, 2015 at 4:43 PM, Denys Vlasenko <dvlasenk@redhat.com> wrote:
> The change which affected how execve clears EXTRA_REGS missed
> 32-bit execve syscalls.
>
> Fix this by using 64-bit execve stub epilogue for them too.
>
> Run-tested.
>
> Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
> CC: Linus Torvalds <torvalds@linux-foundation.org>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Ingo Molnar <mingo@kernel.org>
> CC: Borislav Petkov <bp@alien8.de>
> CC: "H. Peter Anvin" <hpa@zytor.com>
> CC: Andy Lutomirski <luto@amacapital.net>
> CC: Oleg Nesterov <oleg@redhat.com>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Alexei Starovoitov <ast@plumgrid.com>
> CC: Will Drewry <wad@chromium.org>
> CC: Kees Cook <keescook@chromium.org>
> CC: x86@kernel.org
> CC: linux-kernel@vger.kernel.org
> ---
> arch/x86/ia32/ia32entry.S | 2 --
> arch/x86/kernel/entry_64.S | 15 +++++++++++++++
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
> index 5d8f987..a821b1c 100644
> --- a/arch/x86/ia32/ia32entry.S
> +++ b/arch/x86/ia32/ia32entry.S
> @@ -571,8 +571,6 @@ GLOBAL(\label)
>
> PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
> PTREGSCALL stub32_sigreturn, sys32_sigreturn
> - PTREGSCALL stub32_execve, compat_sys_execve
> - PTREGSCALL stub32_execveat, compat_sys_execveat
> PTREGSCALL stub32_fork, sys_fork
> PTREGSCALL stub32_vfork, sys_vfork
>
> diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
> index 1b0793c..8e3ba38 100644
> --- a/arch/x86/kernel/entry_64.S
> +++ b/arch/x86/kernel/entry_64.S
> @@ -461,6 +461,21 @@ ENTRY(stub_x32_execveat)
> END(stub_x32_execveat)
> #endif
>
> +#ifdef CONFIG_IA32_EMULATION
> +ENTRY(stub32_execve)
> + CFI_STARTPROC
> + call compat_sys_execve
> + jmp return_from_execve
> + CFI_ENDPROC
> +END(stub32_execve)
> +ENTRY(stub32_execveat)
> + CFI_STARTPROC
> + call compat_sys_execveat
> + jmp return_from_execve
> + CFI_ENDPROC
> +END(stub32_execveat)
> +#endif
> +
> /*
> * sigreturn is special because it needs to restore all registers on return.
> * This cannot be done with SYSRET, so use the IRET return path instead.
The X32 and IA32 stubs are now identical and should be merged.
--
Brian Gerst
^ permalink raw reply [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Use common code for rt_sigreturn( ) epilogue
2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
` (6 preceding siblings ...)
2015-04-07 20:43 ` [PATCH 8/8] x86/asm/entry/64: Reduce padding in execve stubs Denys Vlasenko
@ 2015-04-09 9:01 ` tip-bot for Denys Vlasenko
7 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:01 UTC (permalink / raw)
To: linux-tip-commits
Cc: tglx, dvlasenk, fweisbec, linux-kernel, keescook, mingo, rostedt,
hpa, wad, brgerst, oleg, luto, ast, bp, torvalds
Commit-ID: 31f0119b817f6474a7b4c48fed7588af1b62c543
Gitweb: http://git.kernel.org/tip/31f0119b817f6474a7b4c48fed7588af1b62c543
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:37 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:24 +0200
x86/asm/entry/64: Use common code for rt_sigreturn() epilogue
Similarly to stub_execve, we can reuse the epilogue in
stub_rt_sigreturn() and stub_x32_rt_sigreturn().
Add a comment explaining why we can't eliminage SAVE_EXTRA_REGS
here.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 3197f41..5252e60 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -527,12 +527,21 @@ END(stub_execveat)
*/
ENTRY(stub_rt_sigreturn)
CFI_STARTPROC
- addq $8, %rsp
- DEFAULT_FRAME 0
- SAVE_EXTRA_REGS
+ DEFAULT_FRAME 0, 8
+ /*
+ * SAVE_EXTRA_REGS result is not normally needed:
+ * sigreturn overwrites all pt_regs->GPREGS.
+ * But sigreturn can fail (!), and there is no easy way to detect that.
+ * To make sure RESTORE_EXTRA_REGS doesn't restore garbage on error,
+ * we SAVE_EXTRA_REGS here.
+ */
+ SAVE_EXTRA_REGS 8
call sys_rt_sigreturn
- movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
+return_from_stub:
+ addq $8, %rsp
+ CFI_ADJUST_CFA_OFFSET -8
RESTORE_EXTRA_REGS
+ movq %rax,RAX(%rsp)
jmp int_ret_from_sys_call
CFI_ENDPROC
END(stub_rt_sigreturn)
@@ -540,13 +549,10 @@ END(stub_rt_sigreturn)
#ifdef CONFIG_X86_X32_ABI
ENTRY(stub_x32_rt_sigreturn)
CFI_STARTPROC
- addq $8, %rsp
- DEFAULT_FRAME 0
- SAVE_EXTRA_REGS
+ DEFAULT_FRAME 0, 8
+ SAVE_EXTRA_REGS 8
call sys32_x32_rt_sigreturn
- movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
- RESTORE_EXTRA_REGS
- jmp int_ret_from_sys_call
+ jmp return_from_stub
CFI_ENDPROC
END(stub_x32_rt_sigreturn)
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat()
2015-04-07 20:43 ` [PATCH 2/8] x86/asm/entry/64: Move stub_x32_execve[at] closer to stub_execveat Denys Vlasenko
@ 2015-04-09 9:02 ` tip-bot for Denys Vlasenko
0 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:02 UTC (permalink / raw)
To: linux-tip-commits
Cc: brgerst, bp, tglx, hpa, torvalds, fweisbec, rostedt, dvlasenk,
oleg, wad, keescook, luto, linux-kernel, mingo, ast
Commit-ID: 05f1752d195c145d02ae40881d0985c2cfbee473
Gitweb: http://git.kernel.org/tip/05f1752d195c145d02ae40881d0985c2cfbee473
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:38 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:24 +0200
x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat()
This is a preparatory patch for moving stub32_execve[at]() to this
file. It makes sense to have all execve stubs in one place, so
that they can reuse code.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 5252e60..f7d9ba6 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -521,6 +521,23 @@ ENTRY(stub_execveat)
CFI_ENDPROC
END(stub_execveat)
+#ifdef CONFIG_X86_X32_ABI
+ENTRY(stub_x32_execve)
+ CFI_STARTPROC
+ DEFAULT_FRAME 0, 8
+ call compat_sys_execve
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub_x32_execve)
+ENTRY(stub_x32_execveat)
+ CFI_STARTPROC
+ DEFAULT_FRAME 0, 8
+ call compat_sys_execveat
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub_x32_execveat)
+#endif
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
@@ -555,23 +572,6 @@ ENTRY(stub_x32_rt_sigreturn)
jmp return_from_stub
CFI_ENDPROC
END(stub_x32_rt_sigreturn)
-
-ENTRY(stub_x32_execve)
- CFI_STARTPROC
- DEFAULT_FRAME 0, 8
- call compat_sys_execve
- jmp return_from_execve
- CFI_ENDPROC
-END(stub_x32_execve)
-
-ENTRY(stub_x32_execveat)
- CFI_STARTPROC
- DEFAULT_FRAME 0, 8
- call compat_sys_execveat
- jmp return_from_execve
- CFI_ENDPROC
-END(stub_x32_execveat)
-
#endif
/*
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
2015-04-07 20:43 ` [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too Denys Vlasenko
2015-04-08 2:39 ` Brian Gerst
@ 2015-04-09 9:02 ` tip-bot for Denys Vlasenko
1 sibling, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:02 UTC (permalink / raw)
To: linux-tip-commits
Cc: keescook, rostedt, ast, fweisbec, mingo, hpa, linux-kernel, wad,
bp, oleg, luto, torvalds, brgerst, tglx, dvlasenk
Commit-ID: 0f90fb979d7b53d80a6d5cb6e127b4b4b249907e
Gitweb: http://git.kernel.org/tip/0f90fb979d7b53d80a6d5cb6e127b4b4b249907e
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:39 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:24 +0200
x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
The change which affected how execve clears EXTRA_REGS missed
32-bit execve syscalls.
Fix this by using 64-bit execve stub epilogue for them too.
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/ia32/ia32entry.S | 2 --
arch/x86/kernel/entry_64.S | 15 +++++++++++++++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 5d8f987..a821b1c 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -571,8 +571,6 @@ GLOBAL(\label)
PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
PTREGSCALL stub32_sigreturn, sys32_sigreturn
- PTREGSCALL stub32_execve, compat_sys_execve
- PTREGSCALL stub32_execveat, compat_sys_execveat
PTREGSCALL stub32_fork, sys_fork
PTREGSCALL stub32_vfork, sys_vfork
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index f7d9ba6..5380b3a 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -538,6 +538,21 @@ ENTRY(stub_x32_execveat)
END(stub_x32_execveat)
#endif
+#ifdef CONFIG_IA32_EMULATION
+ENTRY(stub32_execve)
+ CFI_STARTPROC
+ call compat_sys_execve
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub32_execve)
+ENTRY(stub32_execveat)
+ CFI_STARTPROC
+ call compat_sys_execveat
+ jmp return_from_execve
+ CFI_ENDPROC
+END(stub32_execveat)
+#endif
+
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Optimize [v]fork/clone stubs
2015-04-07 20:43 ` [PATCH 4/8] x86/asm/entry/64: optimize [v]fork/clone stubs Denys Vlasenko
@ 2015-04-09 9:02 ` tip-bot for Denys Vlasenko
0 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:02 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, bp, keescook, ast, rostedt, torvalds, wad, linux-kernel,
luto, dvlasenk, tglx, oleg, fweisbec, brgerst, mingo
Commit-ID: 772951c4e4b06cdffeff499259dba07b544f3166
Gitweb: http://git.kernel.org/tip/772951c4e4b06cdffeff499259dba07b544f3166
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:40 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:25 +0200
x86/asm/entry/64: Optimize [v]fork/clone stubs
Replace "call func; ret" with "jmp func".
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-4-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 5380b3a..ce85256 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -484,8 +484,7 @@ ENTRY(stub_\func)
CFI_STARTPROC
DEFAULT_FRAME 0, 8 /* offset 8: return address */
SAVE_EXTRA_REGS 8
- call sys_\func
- ret
+ jmp sys_\func
CFI_ENDPROC
END(stub_\func)
.endm
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Remove a redundant jump
2015-04-07 20:43 ` [PATCH 5/8] x86/asm/entry/64: remove a redundant jump Denys Vlasenko
@ 2015-04-09 9:03 ` tip-bot for Denys Vlasenko
0 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:03 UTC (permalink / raw)
To: linux-tip-commits
Cc: ast, wad, rostedt, fweisbec, hpa, mingo, brgerst, oleg, torvalds,
dvlasenk, linux-kernel, bp, luto, keescook, tglx
Commit-ID: a30b0085f54efae11f6256df4e4a16af7eefc1c4
Gitweb: http://git.kernel.org/tip/a30b0085f54efae11f6256df4e4a16af7eefc1c4
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:41 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:25 +0200
x86/asm/entry/64: Remove a redundant jump
Jumping to the very next instruction is not very useful:
jmp label
label:
Removing the jump.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-5-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index ce85256..e8ddd51 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1448,7 +1448,6 @@ ENTRY(nmi)
/* If it is below the NMI stack, it is a normal NMI */
jb first_nmi
/* Ah, it is within the NMI stack, treat it as nested */
- jmp nested_nmi
CFI_REMEMBER_STATE
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Simplify jumps in ret_from_fork
2015-04-07 20:43 ` [PATCH 6/8] x86/asm/entry/64: simplify jumps in ret_from_fork Denys Vlasenko
@ 2015-04-09 9:03 ` tip-bot for Denys Vlasenko
0 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:03 UTC (permalink / raw)
To: linux-tip-commits
Cc: wad, ast, mingo, linux-kernel, hpa, luto, torvalds, dvlasenk,
keescook, brgerst, fweisbec, oleg, rostedt, bp, tglx
Commit-ID: 66ad4efa51805964521db03d8aa827a8dd9058b9
Gitweb: http://git.kernel.org/tip/66ad4efa51805964521db03d8aa827a8dd9058b9
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:42 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:25 +0200
x86/asm/entry/64: Simplify jumps in ret_from_fork
Replace
test
jz 1f
jmp label
1:
with
test
jnz label
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-6-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index e8ddd51..a35e5e4 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -608,18 +608,18 @@ ENTRY(ret_from_fork)
RESTORE_EXTRA_REGS
testl $3,CS(%rsp) # from kernel_thread?
- jz 1f
/*
* By the time we get here, we have no idea whether our pt_regs,
* ti flags, and ti status came from the 64-bit SYSCALL fast path,
* the slow path, or one of the ia32entry paths.
- * Use int_ret_from_sys_call to return, since it can safely handle
+ * Use IRET code path to return, since it can safely handle
* all of the above.
*/
- jmp int_ret_from_sys_call
+ jnz int_ret_from_sys_call
-1:
+ /* We came from kernel_thread */
+ /* nb: we depend on RESTORE_EXTRA_REGS above */
movq %rbp, %rdi
call *%rbx
movl $0, RAX(%rsp)
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork
2015-04-07 20:43 ` [PATCH 7/8] x86/asm/entry/64: Remove GET_THREAD_INFO " Denys Vlasenko
@ 2015-04-09 9:03 ` tip-bot for Denys Vlasenko
0 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:03 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, brgerst, bp, oleg, keescook, dvlasenk, rostedt,
fweisbec, mingo, torvalds, luto, tglx, wad, hpa, ast
Commit-ID: 54a81e914b2432a86dd49cf611b0f71ef44ca7ad
Gitweb: http://git.kernel.org/tip/54a81e914b2432a86dd49cf611b0f71ef44ca7ad
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:43 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:26 +0200
x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork
It used to be used to check for _TIF_IA32, but the check has
been removed.
Remove GET_THREAD_INFO() too.
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-7-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index a35e5e4..b67f2fc 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -603,8 +603,6 @@ ENTRY(ret_from_fork)
call schedule_tail # rdi: 'prev' task parameter
- GET_THREAD_INFO(%rcx)
-
RESTORE_EXTRA_REGS
testl $3,CS(%rsp) # from kernel_thread?
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [tip:x86/asm] x86/asm/entry/64: Reduce padding in execve stubs
2015-04-07 20:43 ` [PATCH 8/8] x86/asm/entry/64: Reduce padding in execve stubs Denys Vlasenko
@ 2015-04-09 9:04 ` tip-bot for Denys Vlasenko
0 siblings, 0 replies; 17+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-09 9:04 UTC (permalink / raw)
To: linux-tip-commits
Cc: oleg, torvalds, tglx, brgerst, wad, luto, linux-kernel, keescook,
dvlasenk, ast, mingo, bp, rostedt, fweisbec, hpa
Commit-ID: a37f34a325d90856314ccd4994e1070dcc6bdcc4
Gitweb: http://git.kernel.org/tip/a37f34a325d90856314ccd4994e1070dcc6bdcc4
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 22:43:44 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 9 Apr 2015 10:31:26 +0200
x86/asm/entry/64: Reduce padding in execve stubs
execve stubs are 7 bytes only. Padding them to 16 bytes is a
waste.
text data bss dec hex filename
12594 0 0 12594 3132 entry_64.o.before
12530 0 0 12530 30f2 entry_64.o
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-8-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b67f2fc..c7b2384 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -511,8 +511,12 @@ return_from_execve:
jmp int_ret_from_sys_call
CFI_ENDPROC
END(stub_execve)
-
-ENTRY(stub_execveat)
+/*
+ * Remaining execve stubs are only 7 bytes long.
+ * ENTRY() often aligns to 16 bytes, which in this case has no benefits.
+ */
+ .align 8
+GLOBAL(stub_execveat)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call sys_execveat
@@ -521,14 +525,16 @@ ENTRY(stub_execveat)
END(stub_execveat)
#ifdef CONFIG_X86_X32_ABI
-ENTRY(stub_x32_execve)
+ .align 8
+GLOBAL(stub_x32_execve)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call compat_sys_execve
jmp return_from_execve
CFI_ENDPROC
END(stub_x32_execve)
-ENTRY(stub_x32_execveat)
+ .align 8
+GLOBAL(stub_x32_execveat)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call compat_sys_execveat
@@ -538,13 +544,15 @@ END(stub_x32_execveat)
#endif
#ifdef CONFIG_IA32_EMULATION
-ENTRY(stub32_execve)
+ .align 8
+GLOBAL(stub32_execve)
CFI_STARTPROC
call compat_sys_execve
jmp return_from_execve
CFI_ENDPROC
END(stub32_execve)
-ENTRY(stub32_execveat)
+ .align 8
+GLOBAL(stub32_execveat)
CFI_STARTPROC
call compat_sys_execveat
jmp return_from_execve
^ permalink raw reply related [flat|nested] 17+ messages in thread
end of thread, other threads:[~2015-04-09 9:05 UTC | newest]
Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
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2015-04-07 20:43 [PATCH 1/8] x86/asm/entry/64: Use common code for rt_sigreturn epilogue Denys Vlasenko
2015-04-07 20:43 ` [PATCH 2/8] x86/asm/entry/64: Move stub_x32_execve[at] closer to stub_execveat Denys Vlasenko
2015-04-09 9:02 ` [tip:x86/asm] x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat() tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 3/8] x86/asm/entry: Zero EXTRA_REGS for stub32_execve[at] too Denys Vlasenko
2015-04-08 2:39 ` Brian Gerst
2015-04-09 9:02 ` [tip:x86/asm] x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 4/8] x86/asm/entry/64: optimize [v]fork/clone stubs Denys Vlasenko
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2015-04-07 20:43 ` [PATCH 5/8] x86/asm/entry/64: remove a redundant jump Denys Vlasenko
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2015-04-07 20:43 ` [PATCH 6/8] x86/asm/entry/64: simplify jumps in ret_from_fork Denys Vlasenko
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2015-04-07 20:43 ` [PATCH 7/8] x86/asm/entry/64: Remove GET_THREAD_INFO " Denys Vlasenko
2015-04-09 9:03 ` [tip:x86/asm] x86/asm/entry/64: Remove GET_THREAD_INFO() " tip-bot for Denys Vlasenko
2015-04-07 20:43 ` [PATCH 8/8] x86/asm/entry/64: Reduce padding in execve stubs Denys Vlasenko
2015-04-09 9:04 ` [tip:x86/asm] " tip-bot for Denys Vlasenko
2015-04-09 9:01 ` [tip:x86/asm] x86/asm/entry/64: Use common code for rt_sigreturn( ) epilogue tip-bot for Denys Vlasenko
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