diff options
Diffstat (limited to '0008-Linux-5.11-Test-32bit-compat-with-in_compat_syscall.patch')
| -rw-r--r-- | 0008-Linux-5.11-Test-32bit-compat-with-in_compat_syscall.patch | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/0008-Linux-5.11-Test-32bit-compat-with-in_compat_syscall.patch b/0008-Linux-5.11-Test-32bit-compat-with-in_compat_syscall.patch new file mode 100644 index 000000000000..87b7285fed0e --- /dev/null +++ b/0008-Linux-5.11-Test-32bit-compat-with-in_compat_syscall.patch @@ -0,0 +1,98 @@ +From 2d85a5b7a1011386d66cc36512a54e80b6cfa515 Mon Sep 17 00:00:00 2001 +From: Cheyenne Wills <cwills@sinenomine.net> +Date: Fri, 22 Jan 2021 07:57:55 -0700 +Subject: [PATCH 8/8] Linux 5.11: Test 32bit compat with in_compat_syscall + +Linux 5.11 removed the TIF_IA32 thread flag with commit: + x86: Reclaim TIF_IA32 and TIF_X32 (8d71d2bf6efec) + +The flag TIF_IA32 was being used by openafs to determine if the task was +handling a syscall request from a 32 bit process. Building against a +Linux 5.11 kernel results in a build failure as TIF_IA32 is undefined. + +The function 'in_compat_syscall' was introduced in Linux 4.6 as +the preferred method to determine if a syscall needed to handle a +compatible call (e.g. 32bit application). + +To resolve the build problem, use 'in_compat_syscall' if present (Linux +4.6 and later) to determine if the syscall needs to handle a +compatibility mode call. + +Add autoconf check for in_compat_syscall. + +Notes about in_compat_syscall: + +In Linux 4.6 'in_compat_syscall' was defined for all architectures with +a generic return of 'is_compat_task', but allows architecture specific +overriding implementations (x86 and sparc). + +At 4.6 (and later), the function 'is_compat_task' is defined only for +the following architectures to return: + +Arch Returns +======= ============================== +arm64 test_thread_flag(TIF_32BIT); +mips test_thread_flag(TIF_32BIT_ADDR) +parisc test_ti_thread_flag(task_thread_info(t), TIF_32BIT) +powerpc is_32bit_task() +s390 test_thread_flag(TIF_31BIT) +sparc test_thread_flag(TIF_32BIT) + +If the Linux kernel is not built with compat mode, is_compat_task and +in_compat_syscall is set to always return 0 + +Linux commit that introduced in_compat_syscall: + compat: add in_compat_syscall to ask whether we're in a compat syscall + (5180e3e24fd3e8e7) + +Reviewed-on: https://gerrit.openafs.org/14499 +Reviewed-by: Andrew Deason <adeason@sinenomine.net> +Reviewed-by: Benjamin Kaduk <kaduk@mit.edu> +Tested-by: BuildBot <buildbot@rampaginggeek.com> +(cherry picked from commit 78ef922612bef5f5fd6904896e84b9d2ea802404) + +Change-Id: I4eca62f19ae58fd830915feff5098cec2825f099 +Reviewed-on: https://gerrit.openafs.org/14511 +Reviewed-by: Cheyenne Wills <cwills@sinenomine.net> +Tested-by: Cheyenne Wills <cwills@sinenomine.net> +Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de> +--- + src/afs/LINUX/osi_machdep.h | 4 +++- + src/cf/linux-kernel-func.m4 | 6 ++++++ + 2 files changed, 9 insertions(+), 1 deletion(-) + +diff --git a/src/afs/LINUX/osi_machdep.h b/src/afs/LINUX/osi_machdep.h +index 9ecdaf0bf..066c1885f 100644 +--- a/src/afs/LINUX/osi_machdep.h ++++ b/src/afs/LINUX/osi_machdep.h +@@ -167,7 +167,9 @@ static inline long copyinstr(char *from, char *to, int count, int *length) { + static inline int + afs_in_compat_syscall(void) + { +-# if defined(AFS_SPARC64_LINUX26_ENV) ++# if defined(HAVE_LINUX_IN_COMPAT_SYSCALL) ++ return in_compat_syscall(); ++# elif defined(AFS_SPARC64_LINUX26_ENV) + return test_thread_flag(TIF_32BIT); + # elif defined(AFS_SPARC64_LINUX24_ENV) + return (current->thread.flags & SPARC_FLAG_32BIT) != 0; +diff --git a/src/cf/linux-kernel-func.m4 b/src/cf/linux-kernel-func.m4 +index e45a30540..5b4060238 100644 +--- a/src/cf/linux-kernel-func.m4 ++++ b/src/cf/linux-kernel-func.m4 +@@ -157,6 +157,12 @@ AC_CHECK_LINUX_FUNC([lru_cache_add_file], + [#include <linux/swap.h>], + [lru_cache_add_file(NULL);]) + ++dnl Linux 4.6 introduced in_compat_syscall as replacement for is_compat_task ++dnl for certain platforms. ++AC_CHECK_LINUX_FUNC([in_compat_syscall], ++ [#include <linux/compat.h>], ++ [in_compat_syscall();]) ++ + dnl lru_cache_add exported in Linux 5.8 + dnl replaces lru_cache_add_file + AC_CHECK_LINUX_FUNC([lru_cache_add], +-- +2.30.1 + |