[Qemu-devel] [PATCH] linux-user: Simplify boundary checks on g_posix_timers range

[Alexander Graf <agraf@suse.de>]

We check whether the passed in counter value is negative on all calls
that involve g_posix_timers. However, we AND the value down to 16 bits
right before the check, so they can never be negative.

Simplify all the checks and remove the useless negativity check.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 linux-user/syscall.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index f6c887f..bb68dd4 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9509,7 +9509,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
         /* args: timer_t timerid, int flags, const struct itimerspec *new_value,
          * struct itimerspec * old_value */
         arg1 &= 0xffff;
-        if (arg3 == 0 || arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
+        if (arg3 == 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
             ret = -TARGET_EINVAL;
         } else {
             timer_t htimer = g_posix_timers[arg1];
@@ -9531,7 +9531,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
         arg1 &= 0xffff;
         if (!arg2) {
             return -TARGET_EFAULT;
-        } else if (arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
+        } else if (arg1 >= ARRAY_SIZE(g_posix_timers)) {
             ret = -TARGET_EINVAL;
         } else {
             timer_t htimer = g_posix_timers[arg1];
@@ -9551,7 +9551,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
     {
         /* args: timer_t timerid */
         arg1 &= 0xffff;
-        if (arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
+        if (arg1 >= ARRAY_SIZE(g_posix_timers)) {
             ret = -TARGET_EINVAL;
         } else {
             timer_t htimer = g_posix_timers[arg1];
@@ -9566,7 +9566,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
     {
         /* args: timer_t timerid */
         arg1 &= 0xffff;
-        if (arg1 < 0 || arg1 >= ARRAY_SIZE(g_posix_timers)) {
+        if (arg1 >= ARRAY_SIZE(g_posix_timers)) {
             ret = -TARGET_EINVAL;
         } else {
             timer_t htimer = g_posix_timers[arg1];
-- 
1.7.12.4