Re: [PATCH] Mips: Resolve build issues for the n32 ABI

[Dimitrije Milosevic <Dimitrije.Milosevic@Syrmia.com>]

Ping. :)
This change just landed on LLVM (see https://reviews.llvm.org/rG5d8077565e4196efdd4ed525a64c11a96d5aa5dd).
Unfortunately, I do not have commit access, so if anyone can commit it, that would be great!
Here is the patch with the updated commit message.

libsanitizer: Cherry-pick 5d8077565e41 from upstream

Building the ASAN for the n32 MIPS ABI currently fails, due to a few reasons:
- defined(__mips64), which is set solely based on the architecture type (32-bit/64-bit),
was still used in some places. Therefore, defined(__mips64) is swapped with SANITIZER_MIPS64,
which takes the ABI into account as well - defined(__mips64) &&
_MIPS_SIM == ABI64.
- The n32 ABI still uses 64-bit *Linux* system calls, even though the word size is 32 bits.
- After the transition to canonical system calls
(https://reviews.llvm.org/D124212), the n32 ABI still didn't use them,
even though they are supported,
as per https://github.com/torvalds/linux/blob/master/arch/mips/kernel/syscalls/syscall_n32.tbl.

See https://reviews.llvm.org/D127098.

libsanitizer/ChangeLog:

	* sanitizer_common/sanitizer_linux.cpp (defined): Resolve
	ASAN build issues for the Mips n32 ABI.
	* sanitizer_common/sanitizer_platform.h (defined): Likewise.
---
 .../sanitizer_common/sanitizer_linux.cpp        | 17 ++++++++++-------
 .../sanitizer_common/sanitizer_platform.h       |  2 +-
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cpp b/libsanitizer/sanitizer_common/sanitizer_linux.cpp
index e2c32d679ad..5ba033492e7 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.cpp
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.cpp
@@ -34,7 +34,7 @@
 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
 // access stat from asm/stat.h, without conflicting with definition in
 // sys/stat.h, we use this trick.
-#if defined(__mips64)
+#if SANITIZER_MIPS64
 #include <asm/unistd.h>
 #include <sys/types.h>
 #define stat kernel_stat
@@ -124,8 +124,9 @@ const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
 // Are we using 32-bit or 64-bit Linux syscalls?
 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
 // but it still needs to use 64-bit syscalls.
-#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) ||       \
-                        SANITIZER_WORDSIZE == 64)
+#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
+                        SANITIZER_WORDSIZE == 64 ||                      \
+                        (defined(__mips__) && _MIPS_SIM == _ABIN32))
 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
 #else
 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
@@ -289,7 +290,7 @@ static void stat64_to_stat(struct stat64 *in, struct stat *out) {
 }
 #endif
 
-#if defined(__mips64)
+#if SANITIZER_MIPS64
 // Undefine compatibility macros from <sys/stat.h>
 // so that they would not clash with the kernel_stat
 // st_[a|m|c]time fields
@@ -343,7 +344,8 @@ uptr internal_stat(const char *path, void *buf) {
 #if SANITIZER_FREEBSD
   return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
 #    elif SANITIZER_LINUX
-#      if SANITIZER_WORDSIZE == 64 || SANITIZER_X32
+#      if SANITIZER_WORDSIZE == 64 || SANITIZER_X32 || \
+          (defined(__mips__) && _MIPS_SIM == _ABIN32)
   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
                           0);
 #      else
@@ -366,7 +368,8 @@ uptr internal_lstat(const char *path, void *buf) {
   return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
                           AT_SYMLINK_NOFOLLOW);
 #    elif SANITIZER_LINUX
-#      if defined(_LP64) || SANITIZER_X32
+#      if defined(_LP64) || SANITIZER_X32 ||         \
+          (defined(__mips__) && _MIPS_SIM == _ABIN32)
   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
                           AT_SYMLINK_NOFOLLOW);
 #      else
@@ -1053,7 +1056,7 @@ uptr GetMaxVirtualAddress() {
   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
 #elif SANITIZER_RISCV64
   return (1ULL << 38) - 1;
-# elif defined(__mips64)
+# elif SANITIZER_MIPS64
   return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
 # elif defined(__s390x__)
   return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform.h b/libsanitizer/sanitizer_common/sanitizer_platform.h
index 8fe0d831431..8bd9a327623 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform.h
@@ -159,7 +159,7 @@
 
 #if defined(__mips__)
 #  define SANITIZER_MIPS 1
-#  if defined(__mips64)
+#  if defined(__mips64) && _MIPS_SIM == _ABI64
 #    define SANITIZER_MIPS32 0
 #    define SANITIZER_MIPS64 1
 #  else
-- 
2.25.1


From: Richard Sandiford <richard.sandiford@arm.com>
Sent: Monday, July 4, 2022 1:23 PM
To: Xi Ruoyao via Gcc-patches <gcc-patches@gcc.gnu.org>
Cc: Dimitrije Milosevic <Dimitrije.Milosevic@Syrmia.com>; Xi Ruoyao <xry111@xry111.site>; Djordje Todorovic <Djordje.Todorovic@syrmia.com>
Subject: Re: [PATCH] Mips: Resolve build issues for the n32 ABI 
 
Xi Ruoyao via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> On Fri, 2022-07-01 at 12:40 +0000, Dimitrije Milosevic wrote:
>> Building the ASAN for the n32 MIPS ABI currently fails, due to a few reasons:
>> - defined(__mips64), which is set solely based on the architecture type (32-bit/64-bit), 
>> was still used in some places. Therefore, defined(__mips64) is swapped with SANITIZER_MIPS64, 
>> which takes the ABI into account as well - defined(__mips64) && 
>> _MIPS_SIM == ABI64.
>> - The n32 ABI still uses 64-bit *Linux* system calls, even though the word size is 32 bits.
>> - After the transition to canonical system calls 
>> (https://reviews.llvm.org/D124212), the n32 ABI still didn't use them,
>> even though they are supported,
>> as per https://github.com/torvalds/linux/blob/master/arch/mips/kernel/syscalls/syscall_n32.tbl.
>> 
>> See https://reviews.llvm.org/D127098.
>> 
>>     libsanitizer/ChangeLog:
>>     
>>             * sanitizer_common/sanitizer_linux.cpp (defined): Resolve
>>             ASAN build issues for the Mips n32 ABI.
>>             * sanitizer_common/sanitizer_platform.h (defined): Likewise.
>
> LGTM (with the ChangeLog format fixed), but I think you need to commit
> this into LLVM repository first.  And in the commit message you should
> say something like "cherry-pick 0011aabb... from upstream".  Then we
> still require the approve from a maintainer.

You know this area far better than I do, so: rubber-stamp OK for
cherry-picking the patch into GCC once it's in LLVM.

Thanks,
Richard

>
>> ---
>> 
>>  libsanitizer/sanitizer_common/sanitizer_linux.cpp  | 17 ++++++++++-------
>>  libsanitizer/sanitizer_common/sanitizer_platform.h |  2 +-
>>  2 files changed, 11 insertions(+), 8 deletions(-)
>> 
>> diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cpp b/libsanitizer/sanitizer_common/sanitizer_linux.cpp
>> index e2c32d679ad..5ba033492e7 100644
>> --- a/libsanitizer/sanitizer_common/sanitizer_linux.cpp
>> +++ b/libsanitizer/sanitizer_common/sanitizer_linux.cpp
>> @@ -34,7 +34,7 @@
>>  // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
>>  // access stat from asm/stat.h, without conflicting with definition in
>>  // sys/stat.h, we use this trick.
>> -#if defined(__mips64)
>> +#if SANITIZER_MIPS64
>>  #include <asm/unistd.h>
>>  #include <sys/types.h>
>>  #define stat kernel_stat
>> @@ -124,8 +124,9 @@ const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
>>  // Are we using 32-bit or 64-bit Linux syscalls?
>>  // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
>>  // but it still needs to use 64-bit syscalls.
>> -#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) ||       \
>> -                        SANITIZER_WORDSIZE == 64)
>> +#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
>> +                        SANITIZER_WORDSIZE == 64 ||                      \
>> +                        (defined(__mips__) && _MIPS_SIM == _ABIN32))
>>  # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
>>  #else
>>  # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
>> @@ -289,7 +290,7 @@ static void stat64_to_stat(struct stat64 *in, struct stat *out) {
>>  }
>>  #endif
>>  
>> -#if defined(__mips64)
>> +#if SANITIZER_MIPS64
>>  // Undefine compatibility macros from <sys/stat.h>
>>  // so that they would not clash with the kernel_stat
>>  // st_[a|m|c]time fields
>> @@ -343,7 +344,8 @@ uptr internal_stat(const char *path, void *buf) {
>>  #if SANITIZER_FREEBSD
>>    return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
>>  #    elif SANITIZER_LINUX
>> -#      if SANITIZER_WORDSIZE == 64 || SANITIZER_X32
>> +#      if SANITIZER_WORDSIZE == 64 || SANITIZER_X32 || \
>> +          (defined(__mips__) && _MIPS_SIM == _ABIN32)
>>    return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
>>                            0);
>>  #      else
>> @@ -366,7 +368,8 @@ uptr internal_lstat(const char *path, void *buf) {
>>    return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
>>                            AT_SYMLINK_NOFOLLOW);
>>  #    elif SANITIZER_LINUX
>> -#      if defined(_LP64) || SANITIZER_X32
>> +#      if defined(_LP64) || SANITIZER_X32 ||         \
>> +          (defined(__mips__) && _MIPS_SIM == _ABIN32)
>>    return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
>>                            AT_SYMLINK_NOFOLLOW);
>>  #      else
>> @@ -1053,7 +1056,7 @@ uptr GetMaxVirtualAddress() {
>>    return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
>>  #elif SANITIZER_RISCV64
>>    return (1ULL << 38) - 1;
>> -# elif defined(__mips64)
>> +# elif SANITIZER_MIPS64
>>    return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
>>  # elif defined(__s390x__)
>>    return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
>> diff --git a/libsanitizer/sanitizer_common/sanitizer_platform.h b/libsanitizer/sanitizer_common/sanitizer_platform.h
>> index 8fe0d831431..8bd9a327623 100644
>> --- a/libsanitizer/sanitizer_common/sanitizer_platform.h
>> +++ b/libsanitizer/sanitizer_common/sanitizer_platform.h
>> @@ -159,7 +159,7 @@
>>  
>>  #if defined(__mips__)
>>  #  define SANITIZER_MIPS 1
>> -#  if defined(__mips64)
>> +#  if defined(__mips64) && _MIPS_SIM == _ABI64
>>  #    define SANITIZER_MIPS32 0
>>  #    define SANITIZER_MIPS64 1
>>  #  else
>> 
>> ---