parisc: Fix crash when calling PDC_PAT_MEM PDT firmware function (f520e552) · Commits · 戴 / test

Commit ("parisc: Add Page Deallocation Table (PDT) support") introduced the pdc_pat_mem_read_pd_pdt() firmware helper function, which crashed the system because it trashed the stack if the pdc_pat_mem_read_pd_retinfo struct was located on the stack (and which is in size less than the required 32 64-bit values). Fix it by using the pdc_result struct instead when calling firmware and copy the return values back into the result struct when finished sucessfully. While debugging this code I noticed that the pdc_type wasn't set correctly either, so let's fix that too. Fixes: ("parisc: Add Page Deallocation Table (PDT) support") Signed-off-by:

Helge Deller <deller@gmx.de>

arch/parisc/kernel/firmware.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -1481,12 +1481,19 @@ int pdc_pat_mem_read_pd_pdt(struct pdc_pat_mem_read_pd_retinfo *pret,
		unsigned long offset)
		{
		int retval;
		unsigned long flags;
		unsigned long flags, entries;

		spin_lock_irqsave(&pdc_lock, flags);
		retval = mem_pdc_call(PDC_PAT_MEM, PDC_PAT_MEM_PD_READ,
		__pa(&pret), __pa(pdt_entries_ptr),
		__pa(&pdc_result), __pa(pdt_entries_ptr),
		count, offset);

		if (retval == PDC_OK) {
		entries = min(pdc_result[0], count);
		pret->actual_count_bytes = entries;
		pret->pdt_entries = entries / sizeof(unsigned long);
		}

		spin_unlock_irqrestore(&pdc_lock, flags);

		return retval;

arch/parisc/kernel/pdt.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -112,10 +112,12 @@ void __init pdc_pdt_init(void)
		#ifdef CONFIG_64BIT
		struct pdc_pat_mem_read_pd_retinfo pat_pret;

		/* try old obsolete PAT firmware function first */
		pdt_type = PDT_PAT_OLD;
		ret = pdc_pat_mem_read_cell_pdt(&pat_pret, pdt_entry,
		MAX_PDT_ENTRIES);
		if (ret != PDC_OK) {
		pdt_type = PDT_PAT_OLD;
		pdt_type = PDT_PAT_NEW;
		ret = pdc_pat_mem_read_pd_pdt(&pat_pret, pdt_entry,
		MAX_PDT_TABLE_SIZE, 0);
		}

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