diff options
| author | Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> | 2013-12-04 16:39:34 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2014-03-26 23:09:13 +0100 |
| commit | 078dde5e21dba9f4186ebfc2aef06341fd20efb4 (patch) | |
| tree | 7d2bcea5f8bfc5bdc8bbe0a525ab7359e6721a25 /arch/mips/kernel | |
| parent | b08a9c95f80f2f760f62d70fcd5a869c425d17b6 (diff) | |
MIPS: traps: Set correct address limit for breakpoints and traps
When a breakpoint or trap happens when operating in kernel mode but
on users behalf (eg syscall) it is necessary to change the address
limit to KERNEL_DS so any address checking can be bypassed and print
the correct stack trace.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Diffstat (limited to 'arch/mips/kernel')
| -rw-r--r-- | arch/mips/kernel/traps.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 1a76d114e84..074e857ced2 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -865,6 +865,11 @@ asmlinkage void do_bp(struct pt_regs *regs) enum ctx_state prev_state; unsigned long epc; u16 instr[2]; + mm_segment_t seg; + + seg = get_fs(); + if (!user_mode(regs)) + set_fs(KERNEL_DS); prev_state = exception_enter(); if (get_isa16_mode(regs->cp0_epc)) { @@ -924,6 +929,7 @@ asmlinkage void do_bp(struct pt_regs *regs) do_trap_or_bp(regs, bcode, "Break"); out: + set_fs(seg); exception_exit(prev_state); return; @@ -937,8 +943,13 @@ asmlinkage void do_tr(struct pt_regs *regs) u32 opcode, tcode = 0; enum ctx_state prev_state; u16 instr[2]; + mm_segment_t seg; unsigned long epc = msk_isa16_mode(exception_epc(regs)); + seg = get_fs(); + if (!user_mode(regs)) + set_fs(get_ds()); + prev_state = exception_enter(); if (get_isa16_mode(regs->cp0_epc)) { if (__get_user(instr[0], (u16 __user *)(epc + 0)) || @@ -959,6 +970,7 @@ asmlinkage void do_tr(struct pt_regs *regs) do_trap_or_bp(regs, tcode, "Trap"); out: + set_fs(seg); exception_exit(prev_state); return; |