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parisc: Fix crash when calling PDC_PAT_MEM PDT firmware function

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Commit c9c2877d08 ("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: c9c2877d08 ("parisc: Add Page Deallocation Table (PDT) support")
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Helge Deller 2017-07-25 18:20:54 +02:00
parent 108ea18722
commit f520e55241
2 changed files with 12 additions and 3 deletions
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11
arch/parisc/kernel/firmware.c
View File

@ -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;

4
arch/parisc/kernel/pdt.c
View File

@ -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);
}