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-rw-r--r--arch/x86/kernel/ptrace.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 71691a8310e7..3c5bbe8e4120 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -201,6 +201,7 @@ static int set_segment_reg(struct task_struct *task,
case offsetof(struct user_regs_struct, ss):
if (unlikely(value == 0))
return -EIO;
+ /* Else, fall through */
default:
*pt_regs_access(task_pt_regs(task), offset) = value;
@@ -369,12 +370,22 @@ static int putreg(struct task_struct *child,
case offsetof(struct user_regs_struct,fs_base):
if (value >= TASK_SIZE_MAX)
return -EIO;
- x86_fsbase_write_task(child, value);
+ /*
+ * 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);
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;
- x86_gsbase_write_task(child, value);
+ if (child->thread.gsbase != value)
+ return do_arch_prctl_64(child, ARCH_SET_GS, value);
return 0;
#endif
}
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