From 1073bfd8c0829be06e6ad1cbb4a2f48f8bb594bc Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Oct 2012 12:05:11 +0000 Subject: target-m68k/m68k-semi.c: Log when put_user for returning values fails Abstract out the use of put_user for returning semihosting call results, so that we can log when a guest erroneously attempts a semihosting call with an unwritable argument block. Signed-off-by: Peter Maydell Signed-off-by: Blue Swirl --- target-m68k/m68k-semi.c | 47 +++++++++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 16 deletions(-) (limited to 'target-m68k/m68k-semi.c') diff --git a/target-m68k/m68k-semi.c b/target-m68k/m68k-semi.c index d569bf17c0..9f7a24cdb4 100644 --- a/target-m68k/m68k-semi.c +++ b/target-m68k/m68k-semi.c @@ -133,24 +133,44 @@ static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s) unlock_user(p, addr, sizeof(struct m68k_gdb_stat)); } +static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err) +{ + target_ulong args = env->dregs[1]; + if (put_user_u32(ret, args) || + put_user_u32(err, args + 4)) { + /* The m68k semihosting ABI does not provide any way to report this + * error to the guest, so the best we can do is log it in qemu. + * It is always a guest error not to pass us a valid argument block. + */ + qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value " + "discarded because argument block not writable\n"); + } +} + +static void m68k_semi_return_u64(CPUM68KState *env, uint64_t ret, uint32_t err) +{ + target_ulong args = env->dregs[1]; + if (put_user_u32(ret >> 32, args) || + put_user_u32(ret, args + 4) || + put_user_u32(err, args + 8)) { + /* No way to report this via m68k semihosting ABI; just log it */ + qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value " + "discarded because argument block not writable\n"); + } +} + static int m68k_semi_is_fseek; static void m68k_semi_cb(CPUM68KState *env, target_ulong ret, target_ulong err) { - target_ulong args; - - args = env->dregs[1]; if (m68k_semi_is_fseek) { /* FIXME: We've already lost the high bits of the fseek return value. */ - /* FIXME - handle put_user() failure */ - put_user_u32(0, args); - args += 4; + m68k_semi_return_u64(env, ret, err); m68k_semi_is_fseek = 0; + } else { + m68k_semi_return_u32(env, ret, err); } - /* FIXME - handle put_user() failure */ - put_user_u32(ret, args); - put_user_u32(err, args + 4); } /* Read the input value from the argument block; fail the semihosting @@ -269,10 +289,7 @@ void do_m68k_semihosting(CPUM68KState *env, int nr) arg0, off, arg3); } else { off = lseek(arg0, off, arg3); - /* FIXME - handle put_user() failure */ - put_user_u32(off >> 32, args); - put_user_u32(off, args + 4); - put_user_u32(errno, args + 8); + m68k_semi_return_u64(env, off, errno); } return; } @@ -444,7 +461,5 @@ void do_m68k_semihosting(CPUM68KState *env, int nr) result = 0; } failed: - /* FIXME - handle put_user() failure */ - put_user_u32(result, args); - put_user_u32(errno, args + 4); + m68k_semi_return_u32(env, result, errno); } -- cgit v1.2.1