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| author |   Vasily Gorbik <gor@linux.ibm.com> | 2018-09-14 17:29:39 +0200 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-09-20 13:20:29 +0200 |
| commit | d1befa65823e9c6d013883b8a41d081ec338c489 (patch) | |
| tree | e41d581c2cd188884a016bd9f689eb57ae60f1f5 /arch/s390/include/asm/mmu.h | |
| parent | s390/zcrypt: enable AP bus scan without a valid default domain (diff) | |
| download | linux-dev-d1befa65823e9c6d013883b8a41d081ec338c489.tar.xz linux-dev-d1befa65823e9c6d013883b8a41d081ec338c489.zip | |
s390/vdso: avoid 64-bit vdso mapping for compat tasks
vdso_fault used is_compat_task function (on s390 it tests "current"
thread_info flags) to distinguish compat tasks and map 31-bit vdso
pages. But "current" task might not correspond to mm context.
When 31-bit compat inferior is executed under gdb, gdb does
PTRACE_PEEKTEXT on vdso page, causing vdso_fault with "current" being
64-bit gdb process. So, 31-bit inferior ends up with 64-bit vdso mapped.
To avoid this problem a new compat_mm flag has been introduced into
mm context. This flag is used in vdso_fault and vdso_mremap instead
of is_compat_task.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/mmu.h')
| -rw-r--r-- | arch/s390/include/asm/mmu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h index a8418e1379eb..bcfb6371086f 100644 --- a/arch/s390/include/asm/mmu.h +++ b/arch/s390/include/asm/mmu.h @@ -32,6 +32,8 @@ typedef struct { unsigned int uses_cmm:1; /* The gmaps associated with this context are allowed to use huge pages. */ unsigned int allow_gmap_hpage_1m:1; + /* The mmu context is for compat task */ + unsigned int compat_mm:1; } mm_context_t; #define INIT_MM_CONTEXT(name) \ |