From: Christoph Hellwig <hch@lst.de>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Michael Ellerman <mpe@ellerman.id.au>,
x86@kernel.org
Cc: Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 10/10] powerpc: remove address space overrides using set_fs()
Date: Thu, 27 Aug 2020 17:00:30 +0200 [thread overview]
Message-ID: <20200827150030.282762-11-hch@lst.de> (raw)
In-Reply-To: <20200827150030.282762-1-hch@lst.de>
Stop providing the possibility to override the address space using
set_fs() now that there is no need for that any more.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/powerpc/Kconfig | 1 -
arch/powerpc/include/asm/processor.h | 7 ---
arch/powerpc/include/asm/thread_info.h | 5 +--
arch/powerpc/include/asm/uaccess.h | 62 ++++++++------------------
arch/powerpc/kernel/signal.c | 3 --
arch/powerpc/lib/sstep.c | 6 +--
6 files changed, 22 insertions(+), 62 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3f09d6fdf89405..1f48bbfb3ce99d 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -249,7 +249,6 @@ config PPC
select PCI_SYSCALL if PCI
select PPC_DAWR if PPC64
select RTC_LIB
- select SET_FS
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index ed0d633ab5aa42..f01e4d650c520a 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -83,10 +83,6 @@ struct task_struct;
void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp);
void release_thread(struct task_struct *);
-typedef struct {
- unsigned long seg;
-} mm_segment_t;
-
#define TS_FPR(i) fp_state.fpr[i][TS_FPROFFSET]
#define TS_CKFPR(i) ckfp_state.fpr[i][TS_FPROFFSET]
@@ -148,7 +144,6 @@ struct thread_struct {
unsigned long ksp_vsid;
#endif
struct pt_regs *regs; /* Pointer to saved register state */
- mm_segment_t addr_limit; /* for get_fs() validation */
#ifdef CONFIG_BOOKE
/* BookE base exception scratch space; align on cacheline */
unsigned long normsave[8] ____cacheline_aligned;
@@ -295,7 +290,6 @@ struct thread_struct {
#define INIT_THREAD { \
.ksp = INIT_SP, \
.ksp_limit = INIT_SP_LIMIT, \
- .addr_limit = KERNEL_DS, \
.pgdir = swapper_pg_dir, \
.fpexc_mode = MSR_FE0 | MSR_FE1, \
SPEFSCR_INIT \
@@ -303,7 +297,6 @@ struct thread_struct {
#else
#define INIT_THREAD { \
.ksp = INIT_SP, \
- .addr_limit = KERNEL_DS, \
.fpexc_mode = 0, \
}
#endif
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index ca6c9702570494..46a210b03d2b80 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -90,7 +90,6 @@ void arch_setup_new_exec(void);
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
-#define TIF_FSCHECK 3 /* Check FS is USER_DS on return */
#define TIF_SYSCALL_EMU 4 /* syscall emulation active */
#define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */
#define TIF_PATCH_PENDING 6 /* pending live patching update */
@@ -130,7 +129,6 @@ void arch_setup_new_exec(void);
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE)
#define _TIF_NOHZ (1<<TIF_NOHZ)
-#define _TIF_FSCHECK (1<<TIF_FSCHECK)
#define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU)
#define _TIF_SYSCALL_DOTRACE (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
@@ -138,8 +136,7 @@ void arch_setup_new_exec(void);
#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_NOTIFY_RESUME | _TIF_UPROBE | \
- _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
- _TIF_FSCHECK)
+ _TIF_RESTORE_TM | _TIF_PATCH_PENDING)
#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR)
/* Bits in local_flags */
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 7fe3531ad36a77..39727537d39701 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -8,62 +8,36 @@
#include <asm/extable.h>
#include <asm/kup.h>
-/*
- * The fs value determines whether argument validity checking should be
- * performed or not. If get_fs() == USER_DS, checking is performed, with
- * get_fs() == KERNEL_DS, checking is bypassed.
- *
- * For historical reasons, these macros are grossly misnamed.
- *
- * The fs/ds values are now the highest legal address in the "segment".
- * This simplifies the checking in the routines below.
- */
-
-#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
-
-#define KERNEL_DS MAKE_MM_SEG(~0UL)
#ifdef __powerpc64__
/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
-#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
-#else
-#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
-#endif
-
-#define get_fs() (current->thread.addr_limit)
+#define TASK_SIZE_MAX TASK_SIZE_USER64
-static inline void set_fs(mm_segment_t fs)
+static inline bool __access_ok(unsigned long addr, unsigned long size)
{
- current->thread.addr_limit = fs;
- /* On user-mode return check addr_limit (fs) is correct */
- set_thread_flag(TIF_FSCHECK);
+ if (addr >= TASK_SIZE_MAX)
+ return false;
+ /*
+ * This check is sufficient because there is a large enough gap between
+ * user addresses and the kernel addresses.
+ */
+ return size <= TASK_SIZE_MAX;
}
-
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-#define user_addr_max() (get_fs().seg)
-
-#ifdef __powerpc64__
-/*
- * This check is sufficient because there is a large enough
- * gap between user addresses and the kernel addresses
- */
-#define __access_ok(addr, size, segment) \
- (((addr) <= (segment).seg) && ((size) <= (segment).seg))
-
#else
+#define TASK_SIZE_MAX TASK_SIZE
-static inline int __access_ok(unsigned long addr, unsigned long size,
- mm_segment_t seg)
+static inline bool __access_ok(unsigned long addr, unsigned long size)
{
- if (addr > seg.seg)
- return 0;
- return (size == 0 || size - 1 <= seg.seg - addr);
+ if (addr >= TASK_SIZE_MAX)
+ return false;
+ if (size == 0)
+ return false;
+ return size <= TASK_SIZE_MAX - addr;
}
-
-#endif
+#endif /* __powerpc64__ */
#define access_ok(addr, size) \
(__chk_user_ptr(addr), \
- __access_ok((__force unsigned long)(addr), (size), get_fs()))
+ __access_ok((unsigned long)(addr), (size)))
/*
* These are the main single-value transfer routines. They automatically
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index d15a98c758b8b4..df547d8e31e49c 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -312,9 +312,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
{
user_exit();
- /* Check valid addr_limit, TIF check is done there */
- addr_limit_user_check();
-
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index caee8cc77e1954..8342188ea1acd0 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -108,11 +108,11 @@ static nokprobe_inline long address_ok(struct pt_regs *regs,
{
if (!user_mode(regs))
return 1;
- if (__access_ok(ea, nb, USER_DS))
+ if (__access_ok(ea, nb))
return 1;
- if (__access_ok(ea, 1, USER_DS))
+ if (__access_ok(ea, 1))
/* Access overlaps the end of the user region */
- regs->dar = USER_DS.seg;
+ regs->dar = TASK_SIZE_MAX - 1;
else
regs->dar = ea;
return 0;
--
2.28.0
next prev parent reply other threads:[~2020-08-27 15:01 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-27 15:00 remove the last set_fs() in common code, and remove it for x86 and powerpc v2 Christoph Hellwig
2020-08-27 15:00 ` [PATCH 01/10] fs: don't allow kernel reads and writes without iter ops Christoph Hellwig
2020-08-27 15:58 ` David Laight
2020-08-29 9:23 ` 'Christoph Hellwig'
[not found] ` <20200901064849.GI4299@shao2-debian>
2020-09-01 7:08 ` [fs] ef30fb3c60: kernel write not supported for file /sys/kernel/softlockup_panic Christoph Hellwig
2020-08-27 15:00 ` [PATCH 02/10] fs: don't allow splice read/write without explicit ops Christoph Hellwig
2020-08-27 15:00 ` [PATCH 03/10] uaccess: add infrastructure for kernel builds with set_fs() Christoph Hellwig
2020-08-27 15:00 ` [PATCH 04/10] test_bitmap: skip user bitmap tests for !CONFIG_SET_FS Christoph Hellwig
2020-08-27 15:00 ` [PATCH 05/10] lkdtm: disable set_fs-based " Christoph Hellwig
2020-08-27 18:06 ` Linus Torvalds
2020-08-29 9:24 ` Christoph Hellwig
2020-09-01 18:52 ` Kees Cook
2020-09-01 18:57 ` Kees Cook
2020-09-02 8:09 ` Christoph Hellwig
2020-08-27 15:00 ` [PATCH 06/10] x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h Christoph Hellwig
2020-08-27 15:00 ` [PATCH 07/10] x86: make TASK_SIZE_MAX usable from assembly code Christoph Hellwig
2020-08-27 15:00 ` [PATCH 08/10] x86: remove address space overrides using set_fs() Christoph Hellwig
2020-08-27 18:15 ` Linus Torvalds
2020-08-29 9:25 ` Christoph Hellwig
2020-08-27 15:00 ` [PATCH 09/10] powerpc: use non-set_fs based maccess routines Christoph Hellwig
2020-08-27 15:00 ` Christoph Hellwig [this message]
2020-09-02 6:15 ` [PATCH 10/10] powerpc: remove address space overrides using set_fs() Christophe Leroy
2020-09-02 12:36 ` Christoph Hellwig
2020-09-02 13:13 ` David Laight
2020-09-02 13:24 ` Christophe Leroy
2020-09-02 13:51 ` David Laight
2020-09-02 14:12 ` Christophe Leroy
2020-09-02 15:02 ` David Laight
2020-09-02 15:17 ` Christophe Leroy
2020-09-02 18:02 ` Linus Torvalds
2020-09-03 7:11 ` Christoph Hellwig
2020-09-03 7:27 ` Christophe Leroy
2020-09-03 8:55 ` Christophe Leroy
2020-09-03 7:20 ` Christophe Leroy
2020-08-27 15:31 ` remove the last set_fs() in common code, and remove it for x86 and powerpc v2 Christoph Hellwig
2020-09-01 17:13 ` Christophe Leroy
2020-09-01 17:25 ` Al Viro
2020-09-01 17:42 ` Matthew Wilcox
2020-09-01 18:39 ` Christophe Leroy
2020-09-01 19:01 ` Christophe Leroy
2020-09-02 8:10 ` Christoph Hellwig
2020-10-27 9:29 ` [PATCH 02/10] fs: don't allow splice read/write without explicit ops David Howells
2020-10-27 9:51 ` David Howells
2020-10-27 9:54 ` Christoph Hellwig
2020-10-27 10:38 ` David Howells
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