shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-05 10:31:46 +09:00
Code Issues Packages Projects Releases Wiki Activity

parisc: entry: set W bit for !compat tasks in syscall_restore_rfi()

Browse Source 
commit 5fb1d3ce3e74a4530042795e1e065422295f1371 upstream.

When the kernel leaves to userspace via syscall_restore_rfi(), the
W bit is not set in the new PSW. This doesn't cause any problems
because there's no 64 bit userspace for parisc. Simple static binaries
are usually loaded at addresses way below the 32 bit limit so the W bit
doesn't matter.

Fix this by setting the W bit when TIF_32BIT is not set.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sven Schnelle
2025-10-15 23:21:41 +02:00
committed by Greg Kroah-Hartman
parent d3842cbf13
commit 40feb7bcde
2 changed files with 6 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/parisc/kernel/asm-offsets.c
View File

@@ -258,6 +258,8 @@ int main(void)
BLANK();
DEFINE(TIF_BLOCKSTEP_PA_BIT, 31-TIF_BLOCKSTEP);
DEFINE(TIF_SINGLESTEP_PA_BIT, 31-TIF_SINGLESTEP);
DEFINE(TIF_32BIT_PA_BIT, 31-TIF_32BIT);
BLANK();
DEFINE(ASM_PMD_SHIFT, PMD_SHIFT);
DEFINE(ASM_PGDIR_SHIFT, PGDIR_SHIFT);

5
arch/parisc/kernel/entry.S
View File

@@ -1846,6 +1846,10 @@ syscall_restore_rfi:
extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0
depi -1,7,1,%r20 /* T bit */
#ifdef CONFIG_64BIT
extru,<> %r19,TIF_32BIT_PA_BIT,1,%r0
depi -1,4,1,%r20 /* W bit */
#endif
STREG %r20,TASK_PT_PSW(%r1)
/* Always store space registers, since sr3 can be changed (e.g. fork) */
@@ -1859,7 +1863,6 @@ syscall_restore_rfi:
STREG %r25,TASK_PT_IASQ0(%r1)
STREG %r25,TASK_PT_IASQ1(%r1)
/* XXX W bit??? */
/* Now if old D bit is clear, it means we didn't save all registers
* on syscall entry, so do that now. This only happens on TRACEME
* calls, or if someone attached to us while we were on a syscall.