Re: [PATCH v2 15/18] sparc64: remove CONFIG_SET_FS support
On Wed, Feb 16, 2022 at 7:41 PM Sam Ravnborg wrote: > On Wed, Feb 16, 2022 at 07:34:59PM +0100, Sam Ravnborg wrote: > > > > I think you somehow missed the Kconfig change, and also the related > > sparc32 change which continue to have set_fs() after this patch. Right, thanks for pointing out the issue. > I now notice the sparc32 bits are in the last patch. > To avoid breaking bisect-ability on sparc64 I think you need to merge > the sparc32 changes with this patch, unless the sparc64 changes can > coexist with CONFIG_SET_FS continue to be set. I originally had them in the reverse order and broke bisectability during my rebase. The end result is still fine, but now I need to move the 'select SET_FS' from CONFIG_SPARC to CONFIG_SPARC32 in this patch and then remove it again from there in the last step. I've done that in my local copy now. Arnd ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH v2 15/18] sparc64: remove CONFIG_SET_FS support
Hi Arnd, On Wed, Feb 16, 2022 at 07:34:59PM +0100, Sam Ravnborg wrote: > Hi Arnd. > > On Wed, Feb 16, 2022 at 02:13:29PM +0100, Arnd Bergmann wrote: > > From: Arnd Bergmann > > > > sparc64 uses address space identifiers to differentiate between kernel > > and user space, using ASI_P for kernel threads but ASI_AIUS for normal > > user space, with the option of changing between them. > > > > As nothing really changes the ASI any more, just hardcode ASI_AIUS > > everywhere. Kernel threads are not allowed to access __user pointers > > anyway. > > > > Signed-off-by: Arnd Bergmann > > --- > > arch/sparc/include/asm/processor_64.h | 4 > > arch/sparc/include/asm/switch_to_64.h | 4 +--- > > arch/sparc/include/asm/thread_info_64.h | 4 +--- > > arch/sparc/include/asm/uaccess_64.h | 20 +--- > > arch/sparc/kernel/process_64.c | 12 > > arch/sparc/kernel/traps_64.c| 2 -- > > arch/sparc/lib/NGmemcpy.S | 3 +-- > > arch/sparc/mm/init_64.c | 7 --- > > 8 files changed, 8 insertions(+), 48 deletions(-) > > I think you somehow missed the Kconfig change, and also the related > sparc32 change which continue to have set_fs() after this patch. I now notice the sparc32 bits are in the last patch. To avoid breaking bisect-ability on sparc64 I think you need to merge the sparc32 changes with this patch, unless the sparc64 changes can coexist with CONFIG_SET_FS continue to be set. Sam ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH v2 15/18] sparc64: remove CONFIG_SET_FS support
Hi Arnd. On Wed, Feb 16, 2022 at 02:13:29PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann > > sparc64 uses address space identifiers to differentiate between kernel > and user space, using ASI_P for kernel threads but ASI_AIUS for normal > user space, with the option of changing between them. > > As nothing really changes the ASI any more, just hardcode ASI_AIUS > everywhere. Kernel threads are not allowed to access __user pointers > anyway. > > Signed-off-by: Arnd Bergmann > --- > arch/sparc/include/asm/processor_64.h | 4 > arch/sparc/include/asm/switch_to_64.h | 4 +--- > arch/sparc/include/asm/thread_info_64.h | 4 +--- > arch/sparc/include/asm/uaccess_64.h | 20 +--- > arch/sparc/kernel/process_64.c | 12 > arch/sparc/kernel/traps_64.c| 2 -- > arch/sparc/lib/NGmemcpy.S | 3 +-- > arch/sparc/mm/init_64.c | 7 --- > 8 files changed, 8 insertions(+), 48 deletions(-) I think you somehow missed the Kconfig change, and also the related sparc32 change which continue to have set_fs() after this patch. I did not manage to review the patch - as I am too unfamiliar with the code paths and the set_fs() removal changes. Sam ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[PATCH v2 15/18] sparc64: remove CONFIG_SET_FS support
From: Arnd Bergmann
sparc64 uses address space identifiers to differentiate between kernel
and user space, using ASI_P for kernel threads but ASI_AIUS for normal
user space, with the option of changing between them.
As nothing really changes the ASI any more, just hardcode ASI_AIUS
everywhere. Kernel threads are not allowed to access __user pointers
anyway.
Signed-off-by: Arnd Bergmann
---
arch/sparc/include/asm/processor_64.h | 4
arch/sparc/include/asm/switch_to_64.h | 4 +---
arch/sparc/include/asm/thread_info_64.h | 4 +---
arch/sparc/include/asm/uaccess_64.h | 20 +---
arch/sparc/kernel/process_64.c | 12
arch/sparc/kernel/traps_64.c| 2 --
arch/sparc/lib/NGmemcpy.S | 3 +--
arch/sparc/mm/init_64.c | 7 ---
8 files changed, 8 insertions(+), 48 deletions(-)
diff --git a/arch/sparc/include/asm/processor_64.h
b/arch/sparc/include/asm/processor_64.h
index ae851e8fce4c..89850dff6b03 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -47,10 +47,6 @@
#ifndef __ASSEMBLY__
-typedef struct {
- unsigned char seg;
-} mm_segment_t;
-
/* The Sparc processor specific thread struct. */
/* XXX This should die, everything can go into thread_info now. */
struct thread_struct {
diff --git a/arch/sparc/include/asm/switch_to_64.h
b/arch/sparc/include/asm/switch_to_64.h
index b1d4e2e3210f..14f3c49bfdbc 100644
--- a/arch/sparc/include/asm/switch_to_64.h
+++ b/arch/sparc/include/asm/switch_to_64.h
@@ -20,10 +20,8 @@ do { \
*/
#define switch_to(prev, next, last)\
do { save_and_clear_fpu(); \
- /* If you are tempted to conditionalize the following */\
- /* so that ASI is only written if it changes, think again. */ \
__asm__ __volatile__("wr %%g0, %0, %%asi" \
- : : "r" (task_thread_info(next)->current_ds));\
+ : : "r" (ASI_AIUS));\
trap_block[current_thread_info()->cpu].thread = \
task_thread_info(next); \
__asm__ __volatile__( \
diff --git a/arch/sparc/include/asm/thread_info_64.h
b/arch/sparc/include/asm/thread_info_64.h
index 8047a9caab2f..1a44372e2bc0 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -46,7 +46,7 @@ struct thread_info {
struct pt_regs *kregs;
int preempt_count; /* 0 => preemptable, <0 => BUG
*/
__u8new_child;
- __u8current_ds;
+ __u8__pad;
__u16 cpu;
unsigned long *utraps;
@@ -81,7 +81,6 @@ struct thread_info {
#define TI_KREGS 0x0028
#define TI_PRE_COUNT 0x0030
#define TI_NEW_CHILD 0x0034
-#define TI_CURRENT_DS 0x0035
#define TI_CPU 0x0036
#define TI_UTRAPS 0x0038
#define TI_REG_WINDOW 0x0040
@@ -116,7 +115,6 @@ struct thread_info {
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
- .current_ds = ASI_P, \
.preempt_count = INIT_PREEMPT_COUNT, \
.kregs = (struct pt_regs *)(init_stack+THREAD_SIZE)-1 \
}
diff --git a/arch/sparc/include/asm/uaccess_64.h
b/arch/sparc/include/asm/uaccess_64.h
index 59b9a545df23..94266a5c5b04 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -12,33 +12,15 @@
#include
#include
+#include
/*
* Sparc64 is segmented, though more like the M68K than the I386.
* We use the secondary ASI to address user memory, which references a
* completely different VM map, thus there is zero chance of the user
* doing something queer and tricking us into poking kernel memory.
- *
- * What is left here is basically what is needed for the other parts of
- * the kernel that expect to be able to manipulate, erum, "segments".
- * Or perhaps more properly, permissions.
- *
- * "For historical reasons, these macros are grossly misnamed." -Linus
*/
-#define KERNEL_DS ((mm_segment_t) { ASI_P })
-#define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */
-
-#define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
-
-#include
-
-#define set_fs(val)
\
-do {
\
- current_thread_info()->current_ds = (val).seg;
\
- __asm__ __volatile__ ("wr %%g0, %0, %%
