Commit b3b345af596984d082e2eaef8607c718d80aca6c
Committed by
Greg Kroah-Hartman
1 parent
8f9b87b3dc
ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
commit 06f34e1c28f3608b0ce5b310e41102d3fe7b65a1 upstream. We used to calculate page address differently in 2 cases: 1. In virt_to_page(x) we do --->8--- mem_map + (x - CONFIG_LINUX_LINK_BASE) >> PAGE_SHIFT --->8--- 2. In in pte_page(x) we do --->8--- mem_map + (pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT --->8--- That leads to problems in case PAGE_OFFSET != CONFIG_LINUX_LINK_BASE - different pages will be selected depending on where and how we calculate page address. In particular in the STAR 9000853582 when gdb attempted to read memory of another process it got improper page in get_user_pages() because this is exactly one of the places where we search for a page by pte_page(). The fix is trivial - we need to calculate page address similarly in both cases. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff
arch/arc/include/asm/pgtable.h
... | ... | @@ -259,7 +259,8 @@ |
259 | 259 | #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) |
260 | 260 | |
261 | 261 | #define pte_page(x) (mem_map + \ |
262 | - (unsigned long)(((pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT))) | |
262 | + (unsigned long)(((pte_val(x) - CONFIG_LINUX_LINK_BASE) >> \ | |
263 | + PAGE_SHIFT))) | |
263 | 264 | |
264 | 265 | #define mk_pte(page, pgprot) \ |
265 | 266 | ({ \ |