From 736706bee3298208343a76096370e4f6a5c55915 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 4 Mar 2019 10:39:05 -0800 Subject: 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 Inspired-by: Al Viro Signed-off-by: Linus Torvalds --- arch/mips/include/asm/uaccess.h | 1 - arch/mips/kernel/ftrace.c | 6 +++--- arch/mips/kernel/kgdb.c | 4 ++-- arch/mips/kernel/traps.c | 2 +- 4 files changed, 6 insertions(+), 7 deletions(-) (limited to 'arch/mips') diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h index d43c1dc6ef15..62b298c50905 100644 --- a/arch/mips/include/asm/uaccess.h +++ b/arch/mips/include/asm/uaccess.h @@ -69,7 +69,6 @@ extern u64 __ua_limit; #define USER_DS ((mm_segment_t) { __UA_LIMIT }) #endif -#define get_ds() (KERNEL_DS) #define get_fs() (current_thread_info()->addr_limit) #define set_fs(x) (current_thread_info()->addr_limit = (x)) diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 2ea0ec95efe9..4b5e1f2bfbce 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -86,7 +86,7 @@ static int ftrace_modify_code(unsigned long ip, unsigned int new_code) return -EFAULT; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); flush_icache_range(ip, ip + 8); set_fs(old_fs); @@ -111,7 +111,7 @@ static int ftrace_modify_code_2(unsigned long ip, unsigned int new_code1, ip -= 4; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); flush_icache_range(ip, ip + 8); set_fs(old_fs); @@ -135,7 +135,7 @@ static int ftrace_modify_code_2r(unsigned long ip, unsigned int new_code1, return -EFAULT; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); flush_icache_range(ip, ip + 8); set_fs(old_fs); diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c index 149100e1bc7c..6e574c02e4c3 100644 --- a/arch/mips/kernel/kgdb.c +++ b/arch/mips/kernel/kgdb.c @@ -212,7 +212,7 @@ void kgdb_call_nmi_hook(void *ignored) mm_segment_t old_fs; old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); kgdb_nmicallback(raw_smp_processor_id(), NULL); @@ -318,7 +318,7 @@ static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd, /* Kernel mode. Set correct address limit */ old_fs = get_fs(); - set_fs(get_ds()); + set_fs(KERNEL_DS); if (atomic_read(&kgdb_active) != -1) kgdb_nmicallback(smp_processor_id(), regs); diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index c91097f7b32f..cbab46004e99 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1077,7 +1077,7 @@ asmlinkage void do_tr(struct pt_regs *regs) seg = get_fs(); if (!user_mode(regs)) - set_fs(get_ds()); + set_fs(KERNEL_DS); prev_state = exception_enter(); current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f; -- cgit v1.2.3-59-g8ed1b