From ce90f340855d7a9b3bec24f0fe49a76904242387 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:58 +0100 Subject: [PATCH] x86: x86-64 ptrace get/putreg current task This generalizes the getreg and putreg functions so they can be used on the current task, as well as on a task stopped in TASK_TRACED and switched off. This lays the groundwork to share this code for all kinds of user-mode machine state access, not just ptrace. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/ptrace_64.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/ptrace_64.c b/arch/x86/kernel/ptrace_64.c index 2427548f2a0..5979dbe8e0a 100644 --- a/arch/x86/kernel/ptrace_64.c +++ b/arch/x86/kernel/ptrace_64.c @@ -67,21 +67,29 @@ static int putreg(struct task_struct *child, if (value && (value & 3) != 3) return -EIO; child->thread.fsindex = value & 0xffff; + if (child == current) + loadsegment(fs, child->thread.fsindex); return 0; case offsetof(struct user_regs_struct,gs): if (value && (value & 3) != 3) return -EIO; child->thread.gsindex = value & 0xffff; + if (child == current) + load_gs_index(child->thread.gsindex); return 0; case offsetof(struct user_regs_struct,ds): if (value && (value & 3) != 3) return -EIO; child->thread.ds = value & 0xffff; + if (child == current) + loadsegment(ds, child->thread.ds); return 0; case offsetof(struct user_regs_struct,es): if (value && (value & 3) != 3) return -EIO; child->thread.es = value & 0xffff; + if (child == current) + loadsegment(es, child->thread.es); return 0; case offsetof(struct user_regs_struct,ss): if ((value & 3) != 3) @@ -135,14 +143,32 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) { struct pt_regs *regs = task_pt_regs(child); unsigned long val; + unsigned int seg; switch (regno) { case offsetof(struct user_regs_struct, fs): + if (child == current) { + /* Older gas can't assemble movq %?s,%r?? */ + asm("movl %%fs,%0" : "=r" (seg)); + return seg; + } return child->thread.fsindex; case offsetof(struct user_regs_struct, gs): + if (child == current) { + asm("movl %%gs,%0" : "=r" (seg)); + return seg; + } return child->thread.gsindex; case offsetof(struct user_regs_struct, ds): + if (child == current) { + asm("movl %%ds,%0" : "=r" (seg)); + return seg; + } return child->thread.ds; case offsetof(struct user_regs_struct, es): + if (child == current) { + asm("movl %%es,%0" : "=r" (seg)); + return seg; + } return child->thread.es; case offsetof(struct user_regs_struct, fs_base): /* @@ -152,7 +178,10 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) */ if (child->thread.fs != 0) return child->thread.fs; - if (child->thread.fsindex != FS_TLS_SEL) + seg = child->thread.fsindex; + if (child == current) + asm("movl %%fs,%0" : "=r" (seg)); + if (seg != FS_TLS_SEL) return 0; return get_desc_base(&child->thread.tls_array[FS_TLS]); case offsetof(struct user_regs_struct, gs_base): @@ -161,7 +190,10 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) */ if (child->thread.gs != 0) return child->thread.gs; - if (child->thread.gsindex != GS_TLS_SEL) + seg = child->thread.gsindex; + if (child == current) + asm("movl %%gs,%0" : "=r" (seg)); + if (seg != GS_TLS_SEL) return 0; return get_desc_base(&child->thread.tls_array[GS_TLS]); case offsetof(struct user_regs_struct, flags): -- 2.39.2