[PATCH] parisc: fix personality flag check in copy_thread()

From: Jiri Kosina
Date: Wed Aug 01 2012 - 15:57:55 EST


Directly comparing task_struct->personality against PER_* is not fully
correct, as it doesn't take flags potentially stored in top three bytes
into account.

Analogically, directly forcefully setting personality to PER_LINUX32 or
PER_LINUX discards any flags stored in the top three bytes.

Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---

Found accidentally, untested, I don't have the hardware.

arch/parisc/kernel/process.c | 2 +-
arch/parisc/kernel/sys_parisc.c | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index d4b94b3..2c05a92 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -309,7 +309,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
cregs->ksp = (unsigned long)stack
+ (pregs->gr[21] & (THREAD_SIZE - 1));
cregs->gr[30] = usp;
- if (p->personality == PER_HPUX) {
+ if (personality(p->personality) == PER_HPUX) {
#ifdef CONFIG_HPUX
cregs->kpc = (unsigned long) &hpux_child_return;
#else
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index c9b9322..f309990 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -225,12 +225,12 @@ long parisc_personality(unsigned long personality)
long err;

if (personality(current->personality) == PER_LINUX32
- && personality == PER_LINUX)
- personality = PER_LINUX32;
+ && personality(personality) == PER_LINUX)
+ personality &= ~PER_LINUX | PER_LINUX32;

err = sys_personality(personality);
- if (err == PER_LINUX32)
- err = PER_LINUX;
+ if (personality(err) == PER_LINUX32)
+ err &= ~PER_LINUX32 | PER_LINUX;

return err;
}

--
Jiri Kosina
SUSE Labs
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