diff mbox series

um: Remove dead usage of TIF_IA32

Message ID 20201004050436.1406738-1-krisman@collabora.com
State Accepted
Headers show
Series um: Remove dead usage of TIF_IA32 | expand

Commit Message

Gabriel Krisman Bertazi Oct. 4, 2020, 5:04 a.m. UTC
This seems like a dead artifact since TIF_IA32 is not even defined as a
TI flag for UM.  Looking back in git history, it made sense in the old
days, but it is apparently not used since UM was split out of the x86
arch/.  It is also going away from the x86 tree soon.

Also, I think the variable clean up it performs is not needed as 64-bit
UML doesn't run 32-bit binaries as far as I can tell, and 32-bit UML
has 32-bit ulong.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 arch/x86/um/ptrace_64.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

Comments

Johannes Berg Oct. 4, 2020, 8:10 p.m. UTC | #1
On Sun, 2020-10-04 at 01:04 -0400, Gabriel Krisman Bertazi wrote:
> 
> Also, I think the variable clean up it performs is not needed as 64-bit
> UML doesn't run 32-bit binaries as far as I can tell

Yep, that's true. I was looking into it once _very_ briefly, but no :)

johannes
Richard Weinberger Oct. 4, 2020, 8:19 p.m. UTC | #2
----- Urspr√ľngliche Mail -----
> Von: "Johannes Berg" <johannes@sipsolutions.net>
> An: "Gabriel Krisman Bertazi" <krisman@collabora.com>, "Jeff Dike" <jdike@addtoit.com>, "richard" <richard@nod.at>,
> "anton ivanov" <anton.ivanov@cambridgegreys.com>
> CC: kernel@collabora.com, "linux-um" <linux-um@lists.infradead.org>, oleg@redhat.com
> Gesendet: Sonntag, 4. Oktober 2020 22:10:17
> Betreff: Re: [PATCH] um: Remove dead usage of TIF_IA32

> On Sun, 2020-10-04 at 01:04 -0400, Gabriel Krisman Bertazi wrote:
>> 
>> Also, I think the variable clean up it performs is not needed as 64-bit
>> UML doesn't run 32-bit binaries as far as I can tell
> 
> Yep, that's true. I was looking into it once _very_ briefly, but no :)

Yep. UML has no IA32 emulation and never had.
Looks like a copy&paste leftover.

Thanks,
//richard
diff mbox series

Patch

diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c
index 09a085bde0d4..1401899dee9b 100644
--- a/arch/x86/um/ptrace_64.c
+++ b/arch/x86/um/ptrace_64.c
@@ -52,14 +52,6 @@  static const int reg_offsets[] =
 
 int putreg(struct task_struct *child, int regno, unsigned long value)
 {
-#ifdef TIF_IA32
-	/*
-	 * Some code in the 64bit emulation may not be 64bit clean.
-	 * Don't take any chances.
-	 */
-	if (test_tsk_thread_flag(child, TIF_IA32))
-		value &= 0xffffffff;
-#endif
 	switch (regno) {
 	case R8:
 	case R9:
@@ -137,10 +129,7 @@  int poke_user(struct task_struct *child, long addr, long data)
 unsigned long getreg(struct task_struct *child, int regno)
 {
 	unsigned long mask = ~0UL;
-#ifdef TIF_IA32
-	if (test_tsk_thread_flag(child, TIF_IA32))
-		mask = 0xffffffff;
-#endif
+
 	switch (regno) {
 	case R8:
 	case R9: