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Message-Id: <20220216131332.1489939-16-arnd@kernel.org>
Date: Wed, 16 Feb 2022 14:13:29 +0100
From: Arnd Bergmann <arnd@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>,
Christoph Hellwig <hch@....de>, linux-arch@...r.kernel.org,
linux-mm@...ck.org, linux-api@...r.kernel.org, arnd@...db.de,
linux-kernel@...r.kernel.org, viro@...iv.linux.org.uk
Cc: linux@...linux.org.uk, will@...nel.org, guoren@...nel.org,
bcain@...eaurora.org, geert@...ux-m68k.org, monstr@...str.eu,
tsbogend@...ha.franken.de, nickhu@...estech.com,
green.hu@...il.com, dinguyen@...nel.org, shorne@...il.com,
deller@....de, mpe@...erman.id.au, peterz@...radead.org,
mingo@...hat.com, mark.rutland@....com, hca@...ux.ibm.com,
dalias@...c.org, davem@...emloft.net, richard@....at,
x86@...nel.org, jcmvbkbc@...il.com, ebiederm@...ssion.com,
akpm@...ux-foundation.org, ardb@...nel.org,
linux-alpha@...r.kernel.org, linux-snps-arc@...ts.infradead.org,
linux-csky@...r.kernel.org, linux-hexagon@...r.kernel.org,
linux-ia64@...r.kernel.org, linux-m68k@...ts.linux-m68k.org,
linux-mips@...r.kernel.org, openrisc@...ts.librecores.org,
linux-parisc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
linux-riscv@...ts.infradead.org, linux-s390@...r.kernel.org,
linux-sh@...r.kernel.org, sparclinux@...r.kernel.org,
linux-um@...ts.infradead.org, linux-xtensa@...ux-xtensa.org
Subject: [PATCH v2 15/18] sparc64: remove CONFIG_SET_FS support
From: Arnd Bergmann <arnd@...db.de>
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 <arnd@...db.de>
---
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 */
__u8 new_child;
- __u8 current_ds;
+ __u8 __pad;
__u16 cpu;
unsigned long *utraps;
@@ -81,7 +81,6 @@ struct thread_info {
#define TI_KREGS 0x00000028
#define TI_PRE_COUNT 0x00000030
#define TI_NEW_CHILD 0x00000034
-#define TI_CURRENT_DS 0x00000035
#define TI_CPU 0x00000036
#define TI_UTRAPS 0x00000038
#define TI_REG_WINDOW 0x00000040
@@ -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 <asm/spitfire.h>
#include <asm/processor.h>
+#include <asm-generic/access_ok.h>
/*
* 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 <asm-generic/access_ok.h>
-
-#define set_fs(val) \
-do { \
- current_thread_info()->current_ds = (val).seg; \
- __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
-} while(0)
-
/*
* Test whether a block of memory is a valid user space address.
* Returns 0 if the range is valid, nonzero otherwise.
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index f5b2cac8669f..9a2ceb080ac9 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -106,18 +106,13 @@ static void show_regwindow32(struct pt_regs *regs)
{
struct reg_window32 __user *rw;
struct reg_window32 r_w;
- mm_segment_t old_fs;
__asm__ __volatile__ ("flushw");
rw = compat_ptr((unsigned int)regs->u_regs[14]);
- old_fs = get_fs();
- set_fs (USER_DS);
if (copy_from_user (&r_w, rw, sizeof(r_w))) {
- set_fs (old_fs);
return;
}
- set_fs (old_fs);
printk("l0: %08x l1: %08x l2: %08x l3: %08x "
"l4: %08x l5: %08x l6: %08x l7: %08x\n",
r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
@@ -136,7 +131,6 @@ static void show_regwindow(struct pt_regs *regs)
struct reg_window __user *rw;
struct reg_window *rwk;
struct reg_window r_w;
- mm_segment_t old_fs;
if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
__asm__ __volatile__ ("flushw");
@@ -145,14 +139,10 @@ static void show_regwindow(struct pt_regs *regs)
rwk = (struct reg_window *)
(regs->u_regs[14] + STACK_BIAS);
if (!(regs->tstate & TSTATE_PRIV)) {
- old_fs = get_fs();
- set_fs (USER_DS);
if (copy_from_user (&r_w, rw, sizeof(r_w))) {
- set_fs (old_fs);
return;
}
rwk = &r_w;
- set_fs (old_fs);
}
} else {
show_regwindow32(regs);
@@ -598,7 +588,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
memset(child_trap_frame, 0, child_stack_sz);
__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
(current_pt_regs()->tstate + 1) & TSTATE_CWP;
- t->current_ds = ASI_P;
t->kregs->u_regs[UREG_G1] = sp; /* function */
t->kregs->u_regs[UREG_G2] = arg;
return 0;
@@ -613,7 +602,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
t->kregs->u_regs[UREG_FP] = sp;
__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
(regs->tstate + 1) & TSTATE_CWP;
- t->current_ds = ASI_AIUS;
if (sp != regs->u_regs[UREG_FP]) {
unsigned long csp;
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 21077821f427..5b4de4a89dec 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2857,8 +2857,6 @@ void __init trap_init(void)
TI_PRE_COUNT != offsetof(struct thread_info,
preempt_count) ||
TI_NEW_CHILD != offsetof(struct thread_info, new_child) ||
- TI_CURRENT_DS != offsetof(struct thread_info,
- current_ds) ||
TI_KUNA_REGS != offsetof(struct thread_info,
kern_una_regs) ||
TI_KUNA_INSN != offsetof(struct thread_info,
diff --git a/arch/sparc/lib/NGmemcpy.S b/arch/sparc/lib/NGmemcpy.S
index 8e4d22a6ba0b..ee51c1230689 100644
--- a/arch/sparc/lib/NGmemcpy.S
+++ b/arch/sparc/lib/NGmemcpy.S
@@ -10,8 +10,7 @@
#include <asm/thread_info.h>
#define GLOBAL_SPARE %g7
#define RESTORE_ASI(TMP) \
- ldub [%g6 + TI_CURRENT_DS], TMP; \
- wr TMP, 0x0, %asi;
+ wr %g0, ASI_AIUS, %asi
#else
#define GLOBAL_SPARE %g5
#define RESTORE_ASI(TMP) \
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 1b23639e2fcd..8b1911591581 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -709,9 +709,10 @@ static void __init inherit_prom_mappings(void)
void prom_world(int enter)
{
- if (!enter)
- set_fs(get_fs());
-
+ /*
+ * No need to change the address space any more, just flush
+ * the register windows
+ */
__asm__ __volatile__("flushw");
}
--
2.29.2
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