[PATCH 4.14 101/164] um: Use POSIX ucontext_t instead of struct ucontext

From: Greg Kroah-Hartman
Date: Sun Apr 22 2018 - 11:21:54 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Krzysztof Mazur <krzysiek@xxxxxxxxxxxx>

commit 4d1a535b8ec5e74b42dfd9dc809142653b2597f6 upstream.

glibc 2.26 removed the 'struct ucontext' to "improve" POSIX compliance
and break programs, including User Mode Linux. Fix User Mode Linux
by using POSIX ucontext_t.

This fixes:

arch/um/os-Linux/signal.c: In function 'hard_handler':
arch/um/os-Linux/signal.c:163:22: error: dereferencing pointer to incomplete type 'struct ucontext'
mcontext_t *mc = &uc->uc_mcontext;
arch/x86/um/stub_segv.c: In function 'stub_segv_handler':
arch/x86/um/stub_segv.c:16:13: error: dereferencing pointer to incomplete type 'struct ucontext'
&uc->uc_mcontext);

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Krzysztof Mazur <krzysiek@xxxxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/um/os-Linux/signal.c | 2 +-
arch/x86/um/stub_segv.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -160,7 +160,7 @@ static void (*handlers[_NSIG])(int sig,

static void hard_handler(int sig, siginfo_t *si, void *p)
{
- struct ucontext *uc = p;
+ ucontext_t *uc = p;
mcontext_t *mc = &uc->uc_mcontext;
unsigned long pending = 1UL << sig;

--- a/arch/x86/um/stub_segv.c
+++ b/arch/x86/um/stub_segv.c
@@ -11,7 +11,7 @@
void __attribute__ ((__section__ (".__syscall_stub")))
stub_segv_handler(int sig, siginfo_t *info, void *p)
{
- struct ucontext *uc = p;
+ ucontext_t *uc = p;

GET_FAULTINFO_FROM_MC(*((struct faultinfo *) STUB_DATA),
&uc->uc_mcontext);