diff options
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/crash.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/ftrace_32.S | 75 | ||||
-rw-r--r-- | arch/x86/kernel/kgdb.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/kprobes/common.h | 4 | ||||
-rw-r--r-- | arch/x86/kernel/kprobes/core.c | 29 | ||||
-rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 20 | ||||
-rw-r--r-- | arch/x86/kernel/process_32.c | 16 | ||||
-rw-r--r-- | arch/x86/kernel/ptrace.c | 29 | ||||
-rw-r--r-- | arch/x86/kernel/time.c | 3 | ||||
-rw-r--r-- | arch/x86/kernel/unwind_frame.c | 32 | ||||
-rw-r--r-- | arch/x86/kernel/unwind_orc.c | 2 |
11 files changed, 79 insertions, 147 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 576b2e1bfc12..84e2d3ddd0eb 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -73,14 +73,6 @@ static inline void cpu_crash_vmclear_loaded_vmcss(void) static void kdump_nmi_callback(int cpu, struct pt_regs *regs) { -#ifdef CONFIG_X86_32 - struct pt_regs fixed_regs; - - if (!user_mode(regs)) { - crash_fixup_ss_esp(&fixed_regs, regs); - regs = &fixed_regs; - } -#endif crash_save_cpu(regs, cpu); /* diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S index 0344c3aad4a5..073aab525d80 100644 --- a/arch/x86/kernel/ftrace_32.S +++ b/arch/x86/kernel/ftrace_32.S @@ -10,6 +10,7 @@ #include <asm/ftrace.h> #include <asm/nospec-branch.h> #include <asm/frame.h> +#include <asm/asm-offsets.h> # define function_hook __fentry__ EXPORT_SYMBOL(__fentry__) @@ -90,26 +91,38 @@ END(ftrace_caller) ENTRY(ftrace_regs_caller) /* - * i386 does not save SS and ESP when coming from kernel. - * Instead, to get sp, ®s->sp is used (see ptrace.h). - * Unfortunately, that means eflags must be at the same location - * as the current return ip is. We move the return ip into the - * regs->ip location, and move flags into the return ip location. + * We're here from an mcount/fentry CALL, and the stack frame looks like: + * + * <previous context> + * RET-IP + * + * The purpose of this function is to call out in an emulated INT3 + * environment with a stack frame like: + * + * <previous context> + * gap / RET-IP + * gap + * gap + * gap + * pt_regs + * + * We do _NOT_ restore: ss, flags, cs, gs, fs, es, ds */ - pushl $__KERNEL_CS - pushl 4(%esp) /* Save the return ip */ - pushl $0 /* Load 0 into orig_ax */ + subl $3*4, %esp # RET-IP + 3 gaps + pushl %ss # ss + pushl %esp # points at ss + addl $5*4, (%esp) # make it point at <previous context> + pushfl # flags + pushl $__KERNEL_CS # cs + pushl 7*4(%esp) # ip <- RET-IP + pushl $0 # orig_eax + pushl %gs pushl %fs pushl %es pushl %ds - pushl %eax - - /* Get flags and place them into the return ip slot */ - pushf - popl %eax - movl %eax, 8*4(%esp) + pushl %eax pushl %ebp pushl %edi pushl %esi @@ -119,24 +132,25 @@ ENTRY(ftrace_regs_caller) ENCODE_FRAME_POINTER - movl 12*4(%esp), %eax /* Load ip (1st parameter) */ - subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */ - movl 15*4(%esp), %edx /* Load parent ip (2nd parameter) */ - movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ - pushl %esp /* Save pt_regs as 4th parameter */ + movl PT_EIP(%esp), %eax # 1st argument: IP + subl $MCOUNT_INSN_SIZE, %eax + movl 21*4(%esp), %edx # 2nd argument: parent ip + movl function_trace_op, %ecx # 3rd argument: ftrace_pos + pushl %esp # 4th argument: pt_regs GLOBAL(ftrace_regs_call) call ftrace_stub - addl $4, %esp /* Skip pt_regs */ + addl $4, %esp # skip 4th argument - /* restore flags */ - push 14*4(%esp) - popf + /* place IP below the new SP */ + movl PT_OLDESP(%esp), %eax + movl PT_EIP(%esp), %ecx + movl %ecx, -4(%eax) - /* Move return ip back to its original location */ - movl 12*4(%esp), %eax - movl %eax, 14*4(%esp) + /* place EAX below that */ + movl PT_EAX(%esp), %ecx + movl %ecx, -8(%eax) popl %ebx popl %ecx @@ -144,14 +158,9 @@ GLOBAL(ftrace_regs_call) popl %esi popl %edi popl %ebp - popl %eax - popl %ds - popl %es - popl %fs - popl %gs - /* use lea to not affect flags */ - lea 3*4(%esp), %esp /* Skip orig_ax, ip and cs */ + lea -8(%eax), %esp + popl %eax jmp .Lftrace_ret diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 6690c5652aeb..23297ea64f5f 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -118,14 +118,6 @@ char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) #ifdef CONFIG_X86_32 switch (regno) { - case GDB_SS: - if (!user_mode(regs)) - *(unsigned long *)mem = __KERNEL_DS; - break; - case GDB_SP: - if (!user_mode(regs)) - *(unsigned long *)mem = kernel_stack_pointer(regs); - break; case GDB_GS: case GDB_FS: *(unsigned long *)mem = 0xFFFF; diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h index 2e25f5f3fa1f..7d3a2e2daf01 100644 --- a/arch/x86/kernel/kprobes/common.h +++ b/arch/x86/kernel/kprobes/common.h @@ -72,8 +72,8 @@ " popl %edi\n" \ " popl %ebp\n" \ " popl %eax\n" \ - /* Skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/\ - " addl $24, %esp\n" + /* Skip ds, es, fs, gs, orig_ax, ip, and cs. */\ + " addl $7*4, %esp\n" #endif /* Ensure if the instruction can be boostable */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 6afd8061dbae..bd17dbb15d6a 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -56,7 +56,7 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); -#define stack_addr(regs) ((unsigned long *)kernel_stack_pointer(regs)) +#define stack_addr(regs) ((unsigned long *)regs->sp) #define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\ (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ @@ -718,29 +718,27 @@ asm( ".global kretprobe_trampoline\n" ".type kretprobe_trampoline, @function\n" "kretprobe_trampoline:\n" -#ifdef CONFIG_X86_64 /* We don't bother saving the ss register */ +#ifdef CONFIG_X86_64 " pushq %rsp\n" " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" " call trampoline_handler\n" /* Replace saved sp with true return address. */ - " movq %rax, 152(%rsp)\n" + " movq %rax, 19*8(%rsp)\n" RESTORE_REGS_STRING " popfq\n" #else - " pushf\n" + " pushl %esp\n" + " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" " call trampoline_handler\n" - /* Move flags to cs */ - " movl 56(%esp), %edx\n" - " movl %edx, 52(%esp)\n" - /* Replace saved flags with true return address. */ - " movl %eax, 56(%esp)\n" + /* Replace saved sp with true return address. */ + " movl %eax, 15*4(%esp)\n" RESTORE_REGS_STRING - " popf\n" + " popfl\n" #endif " ret\n" ".size kretprobe_trampoline, .-kretprobe_trampoline\n" @@ -781,16 +779,13 @@ __used __visible void *trampoline_handler(struct pt_regs *regs) INIT_HLIST_HEAD(&empty_rp); kretprobe_hash_lock(current, &head, &flags); /* fixup registers */ -#ifdef CONFIG_X86_64 regs->cs = __KERNEL_CS; - /* On x86-64, we use pt_regs->sp for return address holder. */ - frame_pointer = ®s->sp; -#else - regs->cs = __KERNEL_CS | get_kernel_rpl(); +#ifdef CONFIG_X86_32 + regs->cs |= get_kernel_rpl(); regs->gs = 0; - /* On x86-32, we use pt_regs->flags for return address holder. */ - frame_pointer = ®s->flags; #endif + /* We use pt_regs->sp for return address holder. */ + frame_pointer = ®s->sp; regs->ip = trampoline_address; regs->orig_ax = ~0UL; diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 7c361a24c6df..282b4eb67e30 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -102,14 +102,15 @@ asm ( "optprobe_template_call:\n" ASM_NOP5 /* Move flags to rsp */ - " movq 144(%rsp), %rdx\n" - " movq %rdx, 152(%rsp)\n" + " movq 18*8(%rsp), %rdx\n" + " movq %rdx, 19*8(%rsp)\n" RESTORE_REGS_STRING /* Skip flags entry */ " addq $8, %rsp\n" " popfq\n" #else /* CONFIG_X86_32 */ - " pushf\n" + " pushl %esp\n" + " pushfl\n" SAVE_REGS_STRING " movl %esp, %edx\n" ".global optprobe_template_val\n" @@ -118,9 +119,13 @@ asm ( ".global optprobe_template_call\n" "optprobe_template_call:\n" ASM_NOP5 + /* Move flags into esp */ + " movl 14*4(%esp), %edx\n" + " movl %edx, 15*4(%esp)\n" RESTORE_REGS_STRING - " addl $4, %esp\n" /* skip cs */ - " popf\n" + /* Skip flags entry */ + " addl $4, %esp\n" + " popfl\n" #endif ".global optprobe_template_end\n" "optprobe_template_end:\n" @@ -152,10 +157,9 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) } else { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); /* Save skipped registers */ -#ifdef CONFIG_X86_64 regs->cs = __KERNEL_CS; -#else - regs->cs = __KERNEL_CS | get_kernel_rpl(); +#ifdef CONFIG_X86_32 + regs->cs |= get_kernel_rpl(); regs->gs = 0; #endif regs->ip = (unsigned long)op->kp.addr + INT3_SIZE; diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 2399e910d109..b8ceec4974fe 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -62,27 +62,21 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode) { unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L; unsigned long d0, d1, d2, d3, d6, d7; - unsigned long sp; - unsigned short ss, gs; + unsigned short gs; - if (user_mode(regs)) { - sp = regs->sp; - ss = regs->ss; + if (user_mode(regs)) gs = get_user_gs(regs); - } else { - sp = kernel_stack_pointer(regs); - savesegment(ss, ss); + else savesegment(gs, gs); - } show_ip(regs, KERN_DEFAULT); printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n", regs->ax, regs->bx, regs->cx, regs->dx); printk(KERN_DEFAULT "ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n", - regs->si, regs->di, regs->bp, sp); + regs->si, regs->di, regs->bp, regs->sp); printk(KERN_DEFAULT "DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x EFLAGS: %08lx\n", - (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss, regs->flags); + (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, regs->ss, regs->flags); if (mode != SHOW_REGS_ALL) return; diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index a166c960bc9e..1f92958d8165 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -154,35 +154,6 @@ static inline bool invalid_selector(u16 value) #define FLAG_MASK FLAG_MASK_32 -/* - * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode - * when it traps. The previous stack will be directly underneath the saved - * registers, and 'sp/ss' won't even have been saved. Thus the '®s->sp'. - * - * Now, if the stack is empty, '®s->sp' is out of range. In this - * case we try to take the previous stack. To always return a non-null - * stack pointer we fall back to regs as stack if no previous stack - * exists. - * - * This is valid only for kernel mode traps. - */ -unsigned long kernel_stack_pointer(struct pt_regs *regs) -{ - unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1); - unsigned long sp = (unsigned long)®s->sp; - u32 *prev_esp; - - if (context == (sp & ~(THREAD_SIZE - 1))) - return sp; - - prev_esp = (u32 *)(context); - if (*prev_esp) - return (unsigned long)*prev_esp; - - return (unsigned long)regs; -} -EXPORT_SYMBOL_GPL(kernel_stack_pointer); - static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno) { BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0); diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c index 0e14f6c0d35e..2acbab329754 100644 --- a/arch/x86/kernel/time.c +++ b/arch/x86/kernel/time.c @@ -37,8 +37,7 @@ unsigned long profile_pc(struct pt_regs *regs) #ifdef CONFIG_FRAME_POINTER return *(unsigned long *)(regs->bp + sizeof(long)); #else - unsigned long *sp = - (unsigned long *)kernel_stack_pointer(regs); + unsigned long *sp = (unsigned long *)regs->sp; /* * Return address is either directly at stack pointer * or above a saved flags. Eflags has bits 22-31 zero, diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 6106760de716..a224b5ab103f 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -70,15 +70,6 @@ static void unwind_dump(struct unwind_state *state) } } -static size_t regs_size(struct pt_regs *regs) -{ - /* x86_32 regs from kernel mode are two words shorter: */ - if (IS_ENABLED(CONFIG_X86_32) && !user_mode(regs)) - return sizeof(*regs) - 2*sizeof(long); - - return sizeof(*regs); -} - static bool in_entry_code(unsigned long ip) { char *addr = (char *)ip; @@ -198,12 +189,6 @@ static struct pt_regs *decode_frame_pointer(unsigned long *bp) } #endif -#ifdef CONFIG_X86_32 -#define KERNEL_REGS_SIZE (sizeof(struct pt_regs) - 2*sizeof(long)) -#else -#define KERNEL_REGS_SIZE (sizeof(struct pt_regs)) -#endif - static bool update_stack_state(struct unwind_state *state, unsigned long *next_bp) { @@ -214,7 +199,7 @@ static bool update_stack_state(struct unwind_state *state, size_t len; if (state->regs) - prev_frame_end = (void *)state->regs + regs_size(state->regs); + prev_frame_end = (void *)state->regs + sizeof(*state->regs); else prev_frame_end = (void *)state->bp + FRAME_HEADER_SIZE; @@ -222,7 +207,7 @@ static bool update_stack_state(struct unwind_state *state, regs = decode_frame_pointer(next_bp); if (regs) { frame = (unsigned long *)regs; - len = KERNEL_REGS_SIZE; + len = sizeof(*regs); state->got_irq = true; } else { frame = next_bp; @@ -246,14 +231,6 @@ static bool update_stack_state(struct unwind_state *state, frame < prev_frame_end) return false; - /* - * On 32-bit with user mode regs, make sure the last two regs are safe - * to access: - */ - if (IS_ENABLED(CONFIG_X86_32) && regs && user_mode(regs) && - !on_stack(info, frame, len + 2*sizeof(long))) - return false; - /* Move state to the next frame: */ if (regs) { state->regs = regs; @@ -412,10 +389,9 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, * Pretend that the frame is complete and that BP points to it, but save * the real BP so that we can use it when looking for the next frame. */ - if (regs && regs->ip == 0 && - (unsigned long *)kernel_stack_pointer(regs) >= first_frame) { + if (regs && regs->ip == 0 && (unsigned long *)regs->sp >= first_frame) { state->next_bp = bp; - bp = ((unsigned long *)kernel_stack_pointer(regs)) - 1; + bp = ((unsigned long *)regs->sp) - 1; } /* Initialize stack info and make sure the frame data is accessible: */ diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 33b66b5c5aec..7f79aeebe3ee 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -580,7 +580,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, goto done; state->ip = regs->ip; - state->sp = kernel_stack_pointer(regs); + state->sp = regs->sp; state->bp = regs->bp; state->regs = regs; state->full_regs = true; |