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| author | Nicholas Piggin <npiggin@gmail.com> | 2022-12-16 21:59:30 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-02-10 22:19:56 +1100 |
| commit | 1ee4e35076e36724a62ba2fa29b722fb53eb68f2 (patch) | |
| tree | 71eee0ec6058d0e608c2212ad49e1e23d342ec9c /arch/powerpc/kernel/process.c | |
| parent | dc222fa7737212fe0da513e5b8937c156d02225d (diff) | |
| download | linux-1ee4e35076e36724a62ba2fa29b722fb53eb68f2.tar.gz linux-1ee4e35076e36724a62ba2fa29b722fb53eb68f2.tar.bz2 linux-1ee4e35076e36724a62ba2fa29b722fb53eb68f2.zip | |
powerpc: Skip stack validation checking alternate stacks if they are not allocated
Stack validation in early boot can just bail out of checking alternate
stacks if they are not validated yet. Checking against a NULL stack
could cause NULLish pointer values to be considered valid.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221216115930.2667772-5-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index effe9697905d..4b29ac5ddac6 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2117,6 +2117,9 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, unsigned long stack_page; unsigned long cpu = task_cpu(p); + if (!hardirq_ctx[cpu] || !softirq_ctx[cpu]) + return 0; + stack_page = (unsigned long)hardirq_ctx[cpu]; if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) return 1; @@ -2138,6 +2141,14 @@ static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p, if (!paca_ptrs) return 0; + if (!paca_ptrs[cpu]->emergency_sp) + return 0; + +# ifdef CONFIG_PPC_BOOK3S_64 + if (!paca_ptrs[cpu]->nmi_emergency_sp || !paca_ptrs[cpu]->mc_emergency_sp) + return 0; +#endif + stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE; if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) return 1; |