Commit 31b2b0f8 authored by Suraj Jitindar Singh's avatar Suraj Jitindar Singh Committed by David Gibson
Browse files

target/ppc: Flush TLB on write to PIDR 



The PIDR (process id register) is used to store the id of the currently
running process, which is used to select the process table entry used to
perform address translation. This means that when we write to this register
all the translations in the TLB become outdated as they are for a
previously running process. Thus when this register is written to we need
to invalidate the TLB entries to ensure stale entries aren't used to
to perform translation for the new process, which would result in at best
segfaults or alternatively just random memory being accessed.

Signed-off-by: default avatarSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
[dwg: Fixed compile error for 32-bit targets]
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 8f37e54e

target/ppc/helper.h

+1 −0
Original line number Diff line number Diff line
@@ -709,6 +709,7 @@ DEF_HELPER_FLAGS_1(load_601_rtcu, TCG_CALL_NO_RWG, tl, env) 
DEF_HELPER_FLAGS_1(load_purr, TCG_CALL_NO_RWG, tl, env)

#endif

DEF_HELPER_2(store_sdr1, void, env, tl)

DEF_HELPER_2(store_pidr, void, env, tl)

DEF_HELPER_FLAGS_2(store_tbl, TCG_CALL_NO_RWG, void, env, tl)

DEF_HELPER_FLAGS_2(store_tbu, TCG_CALL_NO_RWG, void, env, tl)

DEF_HELPER_FLAGS_2(store_atbl, TCG_CALL_NO_RWG, void, env, tl)

target/ppc/misc_helper.c

+8 −0
Original line number Diff line number Diff line
@@ -88,6 +88,14 @@ void helper_store_sdr1(CPUPPCState *env, target_ulong val) 
    }

}



void helper_store_pidr(CPUPPCState *env, target_ulong val)

{

    PowerPCCPU *cpu = ppc_env_get_cpu(env);



    env->spr[SPR_BOOKS_PID] = val;

    tlb_flush(CPU(cpu));

}



void helper_store_hid0_601(CPUPPCState *env, target_ulong val)

{

    target_ulong hid0;

target/ppc/translate_init.c

+8 −2
Original line number Diff line number Diff line
@@ -394,8 +394,14 @@ static void spr_write_sdr1 (DisasContext *ctx, int sprn, int gprn) 
    gen_helper_store_sdr1(cpu_env, cpu_gpr[gprn]);

}



/* 64 bits PowerPC specific SPRs */

#if defined(TARGET_PPC64)

/* 64 bits PowerPC specific SPRs */

/* PIDR */

static void spr_write_pidr(DisasContext *ctx, int sprn, int gprn)

{

    gen_helper_store_pidr(cpu_env, cpu_gpr[gprn]);

}



static void spr_read_hior (DisasContext *ctx, int gprn, int sprn)

{

    tcg_gen_ld_tl(cpu_gpr[gprn], cpu_env, offsetof(CPUPPCState, excp_prefix));
@@ -8200,7 +8206,7 @@ static void gen_spr_power8_book4(CPUPPCState *env) 
                     KVM_REG_PPC_ACOP, 0);

    spr_register_kvm(env, SPR_BOOKS_PID, "PID",

                     SPR_NOACCESS, SPR_NOACCESS,

                     &spr_read_generic, &spr_write_generic,

                     &spr_read_generic, &spr_write_pidr,

                     KVM_REG_PPC_PID, 0);

    spr_register_kvm(env, SPR_WORT, "WORT",

                     SPR_NOACCESS, SPR_NOACCESS,