[PATCH 5.18 014/102] parisc: Fix vDSO signal breakage on 32-bit kernel

Greg Kroah-Hartman
2022-07-05T12:31:11Z

From: Helge Deller <deller@gmx.de>

commit aa78fa905b4431c432071a878da99c2b37fc0e79 upstream.

Addition of vDSO support for parisc in kernel v5.18 suddenly broke glibc
signal testcases on a 32-bit kernel.

The trampoline code (sigtramp.S) which is mapped into userspace includes
an offset to the context data on the stack, which is used by gdb and
glibc to get access to registers.

In a 32-bit kernel we used by mistake the offset into the compat context
(which is valid on a 64-bit kernel only) instead of the offset into the
"native" 32-bit context.

Reported-by: John David Anglin <dave.anglin@bell.net>
Tested-by: John David Anglin <dave.anglin@bell.net>
Fixes: df24e1783e6e ("parisc: Add vDSO support")
CC: stable@vger.kernel.org # 5.18
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/parisc/kernel/asm-offsets.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/parisc/kernel/asm-offsets.c b/arch/parisc/kernel/asm-offsets.c
index 2673d57eeb00..94652e13c260 100644
--- a/arch/parisc/kernel/asm-offsets.c
+++ b/arch/parisc/kernel/asm-offsets.c
@@ -224,8 +224,13 @@ int main(void)
BLANK();
DEFINE(ASM_SIGFRAME_SIZE, PARISC_RT_SIGFRAME_SIZE);
DEFINE(SIGFRAME_CONTEXT_REGS, offsetof(struct rt_sigframe, uc.uc_mcontext) - PARISC_RT_SIGFRAME_SIZE);
+#ifdef CONFIG_64BIT
DEFINE(ASM_SIGFRAME_SIZE32, PARISC_RT_SIGFRAME_SIZE32);
DEFINE(SIGFRAME_CONTEXT_REGS32, offsetof(struct compat_rt_sigframe, uc.uc_mcontext) - PARISC_RT_SIGFRAME_SIZE32);
+#else
+ DEFINE(ASM_SIGFRAME_SIZE32, PARISC_RT_SIGFRAME_SIZE);
+ DEFINE(SIGFRAME_CONTEXT_REGS32, offsetof(struct rt_sigframe, uc.uc_mcontext) - PARISC_RT_SIGFRAME_SIZE);
+#endif
BLANK();
DEFINE(ICACHE_BASE, offsetof(struct pdc_cache_info, ic_base));
DEFINE(ICACHE_STRIDE, offsetof(struct pdc_cache_info, ic_stride));
--
2.37.0