Address sanitizer give a hint that it's a NULL pointer dereference rather than zero page

[jonnygrant]

Hello

Currently a NULL pointer dereference gives this error

"Hint: address points to the zero page" Seems a bit of an obscure hint. Could it be changed to just say "NULL pointer dereference" ? That would then follow industry best practice, and CERT, MISRA documentation.

Here is an example:

https://godbolt.org/z/rbG8daz7v

AddressSanitizer:DEADLYSIGNAL

==1==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x0000004010ae bp 0x000000000000 sp 0x7fff9258d908 T0)
==1==The signal is caused by a READ memory access.
==1==Hint: address points to the zero page.
#0 0x4010ae in f(char const*) /app/example.cpp:3
#1 0x4010ae in main /app/example.cpp:10
#2 0x7f7a269e2082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082) (BuildId: 1878e6b475720c7c51969e69ab2d276fae6d1dee)
#3 0x40111d in _start (/app/output.s+0x40111d) (BuildId: bc76a83b79c8b3362b3131001354fa809f091c45)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /app/example.cpp:3 in f(char const*)
==1==ABORTING

[vitalybuka]

you are probably looking for -fsanitize=null

for "Address sanitizer" it was signal handler, with some signal context, and we want to print signals in consistent way

[jonnygrant]

you are probably looking for -fsanitize=null

for "Address sanitizer" it was signal handler, with some signal context, and we want to print signals in consistent way

Hello, Yes I used -fsanitize=null, but it only outputs a runtime error, there's no backtrace.

It seems printing a reasonable hint "NULL pointer dereference" is clearer. It would then be consistent across the whole sanitizer suite, and compilers such as clang and gcc. As a software engineer, we've not worked with anyone who calls that the "zero page". Kind regards.

[vitalybuka]

I didn't realize it's only about the "hint".

[jonnygrant]

Thank you Vitaly, Would be great if the output was is as follows

==1==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x0000004010ae bp 0x000000000000 sp 0x7fff9258d908 T0)
==1==The signal is caused by a READ memory access.
==1==Hint: NULL pointer dereference.