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authorLinus Torvalds2019-03-04 10:39:05 -0800
committerLinus Torvalds2019-03-04 10:50:14 -0800
commit736706bee3298208343a76096370e4f6a5c55915 (patch)
tree3e90fd9d540cb15ac671182d52f9a4ade8657c59 /arch/arm
parent84c4e1f89fefe70554da0ab33be72c9be7994379 (diff)
get rid of legacy 'get_ds()' function
Every in-kernel use of this function defined it to KERNEL_DS (either as an actual define, or as an inline function). It's an entirely historical artifact, and long long long ago used to actually read the segment selector valueof '%ds' on x86. Which in the kernel is always KERNEL_DS. Inspired by a patch from Jann Horn that just did this for a very small subset of users (the ones in fs/), along with Al who suggested a script. I then just took it to the logical extreme and removed all the remaining gunk. Roughly scripted with git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/' git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d' plus manual fixups to remove a few unusual usage patterns, the couple of inline function cases and to fix up a comment that had become stale. The 'get_ds()' function remains in an x86 kvm selftest, since in user space it actually does something relevant. Inspired-by: Jann Horn <jannh@google.com> Inspired-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/uaccess.h1
-rw-r--r--arch/arm/kernel/process.c2
-rw-r--r--arch/arm/xen/hypercall.S3
3 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 42aa4a22803c..ae5a0df5316e 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -59,7 +59,6 @@ extern int __put_user_bad(void);
* Note that this is actually 0x1,0000,0000
*/
#define KERNEL_DS 0x00000000
-#define get_ds() (KERNEL_DS)
#ifdef CONFIG_MMU
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 16601d1442d1..72cc0862a30e 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -150,7 +150,7 @@ void __show_regs(struct pt_regs *regs)
if ((domain & domain_mask(DOMAIN_USER)) ==
domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
segment = "none";
- else if (fs == get_ds())
+ else if (fs == KERNEL_DS)
segment = "kernel";
else
segment = "user";
diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S
index b0b80c0f09f3..b11bba542fac 100644
--- a/arch/arm/xen/hypercall.S
+++ b/arch/arm/xen/hypercall.S
@@ -113,8 +113,7 @@ ENTRY(privcmd_call)
/*
* Disable userspace access from kernel. This is fine to do it
- * unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is
- * called before.
+ * unconditionally as no set_fs(KERNEL_DS) is called before.
*/
uaccess_disable r4