diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2022-11-27 15:49:29 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-12-02 09:54:07 +0300 |
| commit | bc0677363d0ffaec0c56685291e97b080116976c (patch) | |
| tree | d4be47611d9691ac53329eafd432b1b4853daa45 /arch/powerpc/kernel | |
| parent | 32c5209214bd8d4f8c4e9d9b630ef4c671f58e79 (diff) | |
| download | linux-bc0677363d0ffaec0c56685291e97b080116976c.tar.xz | |
powerpc: Rearrange copy_thread child stack creation
This makes it a bit clearer where the stack frame is created, and will
allow easier use of some of the stack offset constants in a later
change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-5-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 5265da2d8034..f93703ea4a12 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1755,13 +1755,16 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) klp_init_thread_info(p); + /* Create initial stack frame. */ + sp -= (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD); + ((unsigned long *)sp)[0] = 0; + /* Copy registers */ - sp -= sizeof(struct pt_regs); - childregs = (struct pt_regs *) sp; + childregs = (struct pt_regs *)(sp + STACK_FRAME_OVERHEAD); if (unlikely(args->fn)) { /* kernel thread */ memset(childregs, 0, sizeof(struct pt_regs)); - childregs->gpr[1] = sp + sizeof(struct pt_regs); + childregs->gpr[1] = sp + (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD); /* function */ if (args->fn) childregs->gpr[14] = ppc_function_entry((void *)args->fn); @@ -1796,7 +1799,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) f = ret_from_fork; } childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX); - sp -= STACK_FRAME_OVERHEAD; /* * The way this works is that at some point in the future @@ -1806,7 +1808,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) * do some house keeping and then return from the fork or clone * system call, using the stack frame created above. */ - ((unsigned long *)sp)[0] = 0; sp -= sizeof(struct pt_regs); kregs = (struct pt_regs *) sp; sp -= STACK_FRAME_OVERHEAD; |