From 864a0922dd128392467611d9857e5138c6a91999 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Wed, 13 Jan 2010 10:16:07 +0000 Subject: x86: kernel_thread() -- initialize SS to a known state Before the kernel_thread was converted into "C" we had pt_regs::ss set to __KERNEL_DS (by SAVE_ALL asm macro). Though I must admit I didn't find any *explicit* load of %ss from this structure the better to be on a safe side and set it to a known value. Signed-off-by: Cyrill Gorcunov Signed-off-by: Ian Campbell Cc: Christian Kujau Cc: Jeremy Fitzhardinge Cc: Brian Gerst LKML-Reference: <1263377768-19600-1-git-send-email-ian.campbell@citrix.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c6ee241c8a98..02c3ee013ccd 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -288,6 +288,8 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) regs.es = __USER_DS; regs.fs = __KERNEL_PERCPU; regs.gs = __KERNEL_STACK_CANARY; +#else + regs.ss = __KERNEL_DS; #endif regs.orig_ax = -1; -- cgit v1.2.3 From 05d43ed8a89c159ff641d472f970e3f1baa66318 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Thu, 28 Jan 2010 22:14:43 -0800 Subject: x86: get rid of the insane TIF_ABI_PENDING bit Now that the previous commit made it possible to do the personality setting at the point of no return, we do just that for ELF binaries. And suddenly all the reasons for that insane TIF_ABI_PENDING bit go away, and we can just make SET_PERSONALITY() just do the obvious thing for a 32-bit compat process. Everything becomes much more straightforward this way. Signed-off-by: H. Peter Anvin Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- arch/x86/ia32/ia32_aout.c | 1 - arch/x86/include/asm/elf.h | 10 ++-------- arch/x86/include/asm/thread_info.h | 2 -- arch/x86/kernel/process.c | 12 ------------ arch/x86/kernel/process_64.c | 11 +++++++++++ 5 files changed, 13 insertions(+), 23 deletions(-) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index 435d2a5323da..f9f472462753 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -311,7 +311,6 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs) /* OK, This is the point of no return */ set_personality(PER_LINUX); set_thread_flag(TIF_IA32); - clear_thread_flag(TIF_ABI_PENDING); setup_new_exec(bprm); diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index b4501ee223ad..1994d3f58443 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -181,14 +181,8 @@ do { \ void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp); #define compat_start_thread start_thread_ia32 -#define COMPAT_SET_PERSONALITY(ex) \ -do { \ - if (test_thread_flag(TIF_IA32)) \ - clear_thread_flag(TIF_ABI_PENDING); \ - else \ - set_thread_flag(TIF_ABI_PENDING); \ - current->personality |= force_personality32; \ -} while (0) +void set_personality_ia32(void); +#define COMPAT_SET_PERSONALITY(ex) set_personality_ia32() #define COMPAT_ELF_PLATFORM ("i686") diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 375c917c37d2..e0d28901e969 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -87,7 +87,6 @@ struct thread_info { #define TIF_NOTSC 16 /* TSC is not accessible in userland */ #define TIF_IA32 17 /* 32bit process */ #define TIF_FORK 18 /* ret_from_fork */ -#define TIF_ABI_PENDING 19 #define TIF_MEMDIE 20 #define TIF_DEBUG 21 /* uses debug registers */ #define TIF_IO_BITMAP 22 /* uses I/O bitmap */ @@ -112,7 +111,6 @@ struct thread_info { #define _TIF_NOTSC (1 << TIF_NOTSC) #define _TIF_IA32 (1 << TIF_IA32) #define _TIF_FORK (1 << TIF_FORK) -#define _TIF_ABI_PENDING (1 << TIF_ABI_PENDING) #define _TIF_DEBUG (1 << TIF_DEBUG) #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) #define _TIF_FREEZE (1 << TIF_FREEZE) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 02c3ee013ccd..c9b3522b6b46 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -115,18 +115,6 @@ void flush_thread(void) { struct task_struct *tsk = current; -#ifdef CONFIG_X86_64 - if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) { - clear_tsk_thread_flag(tsk, TIF_ABI_PENDING); - if (test_tsk_thread_flag(tsk, TIF_IA32)) { - clear_tsk_thread_flag(tsk, TIF_IA32); - } else { - set_tsk_thread_flag(tsk, TIF_IA32); - current_thread_info()->status |= TS_COMPAT; - } - } -#endif - flush_ptrace_hw_breakpoint(tsk); memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); /* diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index f9e033150cdf..41a26a82470a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -521,6 +521,17 @@ void set_personality_64bit(void) current->personality &= ~READ_IMPLIES_EXEC; } +void set_personality_ia32(void) +{ + /* inherit personality from parent */ + + /* Make sure to be in 32bit mode */ + set_thread_flag(TIF_IA32); + + /* Prepare the first "return" to user space */ + current_thread_info()->status |= TS_COMPAT; +} + unsigned long get_wchan(struct task_struct *p) { unsigned long stack; -- cgit v1.2.3