Commit 1239b472 authored by Kwok Cheung Yeung's avatar Kwok Cheung Yeung Committed by Aurelien Jarno
Browse files

linux-user: Save the correct resume address for MIPS signal handling 



The current ISA mode needs to be saved in bit 0 of the resume address.
If the current instruction happens to be in a branch delay slot, then
the address of the preceding jump instruction should be stored instead.
exception_resume_pc already does both of these tasks, so it is
made available and reused.

MIPS_HFLAG_BMASK in hflags is cleared, otherwise QEMU may treat the
first instruction of the signal handler as a delay slot instruction.

Signed-off-by: default avatarKwok Cheung Yeung <kcy@codesourcery.com>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent ea3164aa

linux-user/signal.c

+2 −1
Original line number Diff line number Diff line
@@ -2528,7 +2528,8 @@ setup_sigcontext(CPUMIPSState *regs, struct target_sigcontext *sc) 
    int err = 0;

    int i;



    err |= __put_user(regs->active_tc.PC, &sc->sc_pc);

    err |= __put_user(exception_resume_pc(regs), &sc->sc_pc);

    regs->hflags &= ~MIPS_HFLAG_BMASK;



    __put_user(0, &sc->sc_regs[0]);

    for (i = 1; i < 32; ++i) {

target-mips/cpu.h

+1 −0
Original line number Diff line number Diff line
@@ -668,6 +668,7 @@ void r4k_invalidate_tlb (CPUMIPSState *env, int idx, int use_extra); 
hwaddr cpu_mips_translate_address (CPUMIPSState *env, target_ulong address,

		                               int rw);

#endif

target_ulong exception_resume_pc (CPUMIPSState *env);



static inline void cpu_get_tb_cpu_state(CPUMIPSState *env, target_ulong *pc,

                                        target_ulong *cs_base, int *flags)

target-mips/helper.c

+2 −2
Original line number Diff line number Diff line
@@ -366,8 +366,7 @@ static const char * const excp_names[EXCP_LAST + 1] = { 
    [EXCP_CACHE] = "cache error",

};



#if !defined(CONFIG_USER_ONLY)

static target_ulong exception_resume_pc (CPUMIPSState *env)

target_ulong exception_resume_pc (CPUMIPSState *env)

{

    target_ulong bad_pc;

    target_ulong isa_mode;
@@ -383,6 +382,7 @@ static target_ulong exception_resume_pc (CPUMIPSState *env) 
    return bad_pc;

}



#if !defined(CONFIG_USER_ONLY)

static void set_hflags_for_handler (CPUMIPSState *env)

{

    /* Exception handlers are entered in 32-bit mode.  */