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linux-user: Simplify timerid checks on g_posix_timers range

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We check whether the passed in timer id is negative on all calls
that involve g_posix_timers.

However, these checks are bogus. First off we limit the timer_id to
16 bits which is not what Linux does. Then we check whether it's negative
which it can't be because we masked it.

We can safely remove the masking. For the negativity check we can just
treat the timerid as unsigned and only check for upper boundaries.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Alexander Graf 2014-08-22 13:56:18 +02:00 committed by Riku Voipio
parent a59b5e35d1
commit e52a99f756
1 changed files with 17 additions and 13 deletions
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30
linux-user/syscall.c
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@ -9615,11 +9615,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
{ {
/* args: timer_t timerid, int flags, const struct itimerspec *new_value, /* args: timer_t timerid, int flags, const struct itimerspec *new_value,
* struct itimerspec * old_value */ * struct itimerspec * old_value */
arg1 &= 0xffff; target_ulong timerid = arg1;
if (arg3 == 0 || arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
if (arg3 == 0 || timerid >= ARRAY_SIZE(g_posix_timers)) {
ret = -TARGET_EINVAL; ret = -TARGET_EINVAL;
} else { } else {
timer_t htimer = g_posix_timers[arg1]; timer_t htimer = g_posix_timers[timerid];
struct itimerspec hspec_new = {{0},}, hspec_old = {{0},}; struct itimerspec hspec_new = {{0},}, hspec_old = {{0},};
target_to_host_itimerspec(&hspec_new, arg3); target_to_host_itimerspec(&hspec_new, arg3);
@ -9635,13 +9636,14 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
case TARGET_NR_timer_gettime: case TARGET_NR_timer_gettime:
{ {
/* args: timer_t timerid, struct itimerspec *curr_value */ /* args: timer_t timerid, struct itimerspec *curr_value */
arg1 &= 0xffff; target_ulong timerid = arg1;
if (!arg2) { if (!arg2) {
return -TARGET_EFAULT; return -TARGET_EFAULT;
} else if (arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) { } else if (timerid >= ARRAY_SIZE(g_posix_timers)) {
ret = -TARGET_EINVAL; ret = -TARGET_EINVAL;
} else { } else {
timer_t htimer = g_posix_timers[arg1]; timer_t htimer = g_posix_timers[timerid];
struct itimerspec hspec; struct itimerspec hspec;
ret = get_errno(timer_gettime(htimer, &hspec)); ret = get_errno(timer_gettime(htimer, &hspec));
@ -9657,11 +9659,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
case TARGET_NR_timer_getoverrun: case TARGET_NR_timer_getoverrun:
{ {
/* args: timer_t timerid */ /* args: timer_t timerid */
arg1 &= 0xffff; target_ulong timerid = arg1;
if (arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
if (timerid >= ARRAY_SIZE(g_posix_timers)) {
ret = -TARGET_EINVAL; ret = -TARGET_EINVAL;
} else { } else {
timer_t htimer = g_posix_timers[arg1]; timer_t htimer = g_posix_timers[timerid];
ret = get_errno(timer_getoverrun(htimer)); ret = get_errno(timer_getoverrun(htimer));
} }
break; break;
@ -9672,13 +9675,14 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
case TARGET_NR_timer_delete: case TARGET_NR_timer_delete:
{ {
/* args: timer_t timerid */ /* args: timer_t timerid */
arg1 &= 0xffff; target_ulong timerid = arg1;
if (arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
if (timerid >= ARRAY_SIZE(g_posix_timers)) {
ret = -TARGET_EINVAL; ret = -TARGET_EINVAL;
} else { } else {
timer_t htimer = g_posix_timers[arg1]; timer_t htimer = g_posix_timers[timerid];
ret = get_errno(timer_delete(htimer)); ret = get_errno(timer_delete(htimer));
g_posix_timers[arg1] = 0; g_posix_timers[timerid] = 0;
} }
break; break;
} }