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-rw-r--r--arch/x86/kernel/ptrace.c59
1 files changed, 10 insertions, 49 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index a166c960bc9e..71691a8310e7 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -25,6 +25,7 @@
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <linux/context_tracking.h>
+#include <linux/nospec.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
@@ -154,35 +155,6 @@ 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 '&regs->sp'.
- *
- * Now, if the stack is empty, '&regs->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)&regs->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);
@@ -397,22 +369,12 @@ static int putreg(struct task_struct *child,
case offsetof(struct user_regs_struct,fs_base):
if (value >= TASK_SIZE_MAX)
return -EIO;
- /*
- * When changing the FS base, use do_arch_prctl_64()
- * to set the index to zero and to set the base
- * as requested.
- */
- if (child->thread.fsbase != value)
- return do_arch_prctl_64(child, ARCH_SET_FS, value);
+ x86_fsbase_write_task(child, value);
return 0;
case offsetof(struct user_regs_struct,gs_base):
- /*
- * Exactly the same here as the %fs handling above.
- */
if (value >= TASK_SIZE_MAX)
return -EIO;
- if (child->thread.gsbase != value)
- return do_arch_prctl_64(child, ARCH_SET_GS, value);
+ x86_gsbase_write_task(child, value);
return 0;
#endif
}
@@ -645,7 +607,8 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
unsigned long val = 0;
if (n < HBP_NUM) {
- struct perf_event *bp = thread->ptrace_bps[n];
+ int index = array_index_nospec(n, HBP_NUM);
+ struct perf_event *bp = thread->ptrace_bps[index];
if (bp)
val = bp->hw.info.address;
@@ -747,9 +710,6 @@ static int ioperm_get(struct task_struct *target,
void ptrace_disable(struct task_struct *child)
{
user_disable_single_step(child);
-#ifdef TIF_SYSCALL_EMU
- clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-#endif
}
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
@@ -1361,18 +1321,19 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
#endif
}
-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
- int error_code, int si_code)
+void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
{
+ struct task_struct *tsk = current;
+
tsk->thread.trap_nr = X86_TRAP_DB;
tsk->thread.error_code = error_code;
/* Send us the fake SIGTRAP */
force_sig_fault(SIGTRAP, si_code,
- user_mode(regs) ? (void __user *)regs->ip : NULL, tsk);
+ user_mode(regs) ? (void __user *)regs->ip : NULL);
}
void user_single_step_report(struct pt_regs *regs)
{
- send_sigtrap(current, regs, 0, TRAP_BRKPT);
+ send_sigtrap(regs, 0, TRAP_BRKPT);
}