diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-11 15:33:48 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-11 15:33:48 -0800 |
commit | 606e9ad20094f6d500166881d301f31a51bc8aa7 (patch) | |
tree | 2dba3d8b0fefcf07ab995a044711494f636fb7d7 /arch/arm64 | |
parent | ac61145a725ab0411c5f8ed9aeca6202076ecfd8 (diff) | |
parent | 457677c70c7672a4586b0b8abc396cc1ecdd376d (diff) |
Merge tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull thread fixes from Christian Brauner:
"This contains a series of patches to fix CLONE_SETTLS when used with
clone3().
The clone3() syscall passes the tls argument through struct clone_args
instead of a register. This means, all architectures that do not
implement copy_thread_tls() but still support CLONE_SETTLS via
copy_thread() expecting the tls to be located in a register argument
based on clone() are currently unfortunately broken. Their tls value
will be garbage.
The patch series fixes this on all architectures that currently define
__ARCH_WANT_SYS_CLONE3. It also adds a compile-time check to ensure
that any architecture that enables clone3() in the future is forced to
also implement copy_thread_tls().
My ultimate goal is to get rid of the copy_thread()/copy_thread_tls()
split and just have copy_thread_tls() at some point in the not too
distant future (Maybe even renaming copy_thread_tls() back to simply
copy_thread() once the old function is ripped from all arches). This
is dependent now on all arches supporting clone3().
While all relevant arches do that now there are still four missing:
ia64, m68k, sh and sparc. They have the system call reserved, but not
implemented. Once they all implement clone3() we can get rid of
ARCH_WANT_SYS_CLONE3 and HAVE_COPY_THREAD_TLS.
This series also includes a minor fix for the arm64 uapi headers which
caused __NR_clone3 to be missing from the exported user headers.
Unfortunately the series came in a little late especially given that
it touches a range of architectures. Due to the holidays not all arch
maintainers responded in time probably due to their backlog. Will and
Arnd have thankfully acked the arm specific changes.
Given that the changes are straightforward and rather minimal combined
with the fact the that clone3() with CLONE_SETTLS is broken I decided
to send them post rc3 nonetheless"
* tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
um: Implement copy_thread_tls
clone3: ensure copy_thread_tls is implemented
xtensa: Implement copy_thread_tls
riscv: Implement copy_thread_tls
parisc: Implement copy_thread_tls
arm: Implement copy_thread_tls
arm64: Implement copy_thread_tls
arm64: Move __ARCH_WANT_SYS_CLONE3 definition to uapi headers
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
-rw-r--r-- | arch/arm64/include/asm/unistd.h | 1 | ||||
-rw-r--r-- | arch/arm64/include/uapi/asm/unistd.h | 1 | ||||
-rw-r--r-- | arch/arm64/kernel/process.c | 10 |
4 files changed, 7 insertions, 6 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b1b4476ddb83..e688dfad0b72 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -138,6 +138,7 @@ config ARM64 select HAVE_CMPXCHG_DOUBLE select HAVE_CMPXCHG_LOCAL select HAVE_CONTEXT_TRACKING + select HAVE_COPY_THREAD_TLS select HAVE_DEBUG_BUGVERBOSE select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 2629a68b8724..5af82587909e 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -42,7 +42,6 @@ #endif #define __ARCH_WANT_SYS_CLONE -#define __ARCH_WANT_SYS_CLONE3 #ifndef __COMPAT_SYSCALL_NR #include <uapi/asm/unistd.h> diff --git a/arch/arm64/include/uapi/asm/unistd.h b/arch/arm64/include/uapi/asm/unistd.h index 4703d218663a..f83a70e07df8 100644 --- a/arch/arm64/include/uapi/asm/unistd.h +++ b/arch/arm64/include/uapi/asm/unistd.h @@ -19,5 +19,6 @@ #define __ARCH_WANT_NEW_STAT #define __ARCH_WANT_SET_GET_RLIMIT #define __ARCH_WANT_TIME32_SYSCALLS +#define __ARCH_WANT_SYS_CLONE3 #include <asm-generic/unistd.h> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 71f788cd2b18..d54586d5b031 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -360,8 +360,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) asmlinkage void ret_from_fork(void) asm("ret_from_fork"); -int copy_thread(unsigned long clone_flags, unsigned long stack_start, - unsigned long stk_sz, struct task_struct *p) +int copy_thread_tls(unsigned long clone_flags, unsigned long stack_start, + unsigned long stk_sz, struct task_struct *p, unsigned long tls) { struct pt_regs *childregs = task_pt_regs(p); @@ -394,11 +394,11 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, } /* - * If a TLS pointer was passed to clone (4th argument), use it - * for the new thread. + * If a TLS pointer was passed to clone, use it for the new + * thread. */ if (clone_flags & CLONE_SETTLS) - p->thread.uw.tp_value = childregs->regs[3]; + p->thread.uw.tp_value = tls; } else { memset(childregs, 0, sizeof(struct pt_regs)); childregs->pstate = PSR_MODE_EL1h; |