[PATCH] musl: fix signed compare warning

[Daniel Santos]

On 7/4/20 10:19 AM, Hauke Mehrtens wrote:
> On 6/25/20 1:12 AM, Daniel Santos wrote:
>> Signed-off-by: Daniel Santos <daniel.santos at pobox.com>
>> ---
>>  .../210-Fix-signed-compare-warning.patch      | 26 +++++++++++++++++++
>>  1 file changed, 26 insertions(+)
>>  create mode 100644 toolchain/musl/patches/210-Fix-signed-compare-warning.patch
>>
>> diff --git a/toolchain/musl/patches/210-Fix-signed-compare-warning.patch b/toolchain/musl/patches/210-Fix-signed-compare-warning.patch
>> new file mode 100644
>> index 0000000000..5d5d2f865e
>> --- /dev/null
>> +++ b/toolchain/musl/patches/210-Fix-signed-compare-warning.patch
>> @@ -0,0 +1,26 @@
>> +From 7627aac4e5381546baeb0d6bef6675e9107cd751 Mon Sep 17 00:00:00 2001
>> +From: Daniel Santos <daniel.santos at pobox.com>
>> +Date: Sat, 25 Apr 2020 12:18:15 -0500
>> +Subject: Fix signed compare warning
>> +
>> +Signed-off-by: Daniel Santos <daniel.santos at pobox.com>
>> +---
>> + src/thread/__timedwait.c | 2 +-
>> + 1 file changed, 1 insertion(+), 1 deletion(-)
>> +
>> +diff --git a/src/thread/__timedwait.c b/src/thread/__timedwait.c
>> +index 666093be..9829b93e 100644
>> +--- a/src/thread/__timedwait.c
>> ++++ b/src/thread/__timedwait.c
>> +@@ -38,7 +38,7 @@ int __timedwait_cp(volatile int *addr, int val,
>> + 	if (priv) priv = FUTEX_PRIVATE;
>> + 
>> + 	if (at) {
>> +-		if (at->tv_nsec >= 1000000000UL) return EINVAL;
>> ++		if ((unsigned long)at->tv_nsec >= 1000000000UL) return EINVAL;
>> + 		if (__clock_gettime(clk, &to)) return EINVAL;
>> + 		to.tv_sec = at->tv_sec - to.tv_sec;
>> + 		if ((to.tv_nsec = at->tv_nsec - to.tv_nsec) < 0) {
>> +-- 
>> +2.24.1
>> +
>>
> Thank you for also sending this to upstream musl.
>
> As this was rejected upstream I would also reject it for OpenWrt for now:
> https://www.openwall.com/lists/musl/2020/06/26/4
>
> Hauke
>
Thank you Hauke.  It appears that the musl mailing list is "reply to
list only", so I didn't see the response!  I've updated my mail filters
so I'll get them in my inbox in the future.

I'm not sure how to follow up the upstream response.  I like warnings,
but I'm guessing upstream relies on rigorous scrutiny over warnings. 
Either way, if we enable -Wextra in OpenWRT (or elsewhere, as I had),
we'll want to add -Wno-sign-compare.  It would be good to document this
somewhere.

Anyway, thank you.
Daniel