commit 0a987645672ebde7844a9c0732a5a25f3d4bb6c6 upstream.
Commit a78ff1112263 ("um: add extended processor state save/restore support") and b6024b21fec8 ("um: extend fpstate to _xstate to support YMM registers") forced the use of the x86 FP _xstate and PTRACE_GETREGSET/SETREGSET. On older hosts, we would neither be able to build UML nor run it anymore with these two commits applied because we don't have definitions for struct _xstate nor these two ptrace requests.
We can determine at build time which fp context structure to check against, just like we can keep using the old i387 fp save/restore if PTRACE_GETRESET/SETREGSET are not defined.
Fixes: a78ff1112263 ("um: add extended processor state save/restore support") Fixes: b6024b21fec8 ("um: extend fpstate to _xstate to support YMM registers") Change-Id: I2cda034c8a6637de392c2740a993982ad132bda5 Signed-off-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Alessio Balsini balsini@android.com --- arch/x86/um/os-Linux/registers.c | 12 ++++++++---- arch/x86/um/user-offsets.c | 4 ++++ 2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c index 00f54a91bb4b..28775f55bde2 100644 --- a/arch/x86/um/os-Linux/registers.c +++ b/arch/x86/um/os-Linux/registers.c @@ -26,6 +26,7 @@ int save_i387_registers(int pid, unsigned long *fp_regs)
int save_fp_registers(int pid, unsigned long *fp_regs) { +#ifdef PTRACE_GETREGSET struct iovec iov;
if (have_xstate_support) { @@ -34,9 +35,9 @@ int save_fp_registers(int pid, unsigned long *fp_regs) if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) < 0) return -errno; return 0; - } else { + } else +#endif return save_i387_registers(pid, fp_regs); - } }
int restore_i387_registers(int pid, unsigned long *fp_regs) @@ -48,6 +49,7 @@ int restore_i387_registers(int pid, unsigned long *fp_regs)
int restore_fp_registers(int pid, unsigned long *fp_regs) { +#ifdef PTRACE_SETREGSET struct iovec iov;
if (have_xstate_support) { @@ -56,9 +58,9 @@ int restore_fp_registers(int pid, unsigned long *fp_regs) if (ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov) < 0) return -errno; return 0; - } else { + } else +#endif return restore_i387_registers(pid, fp_regs); - } }
#ifdef __i386__ @@ -122,6 +124,7 @@ int put_fp_registers(int pid, unsigned long *regs)
void arch_init_registers(int pid) { +#ifdef PTRACE_GETREGSET struct _xstate fp_regs; struct iovec iov;
@@ -129,6 +132,7 @@ void arch_init_registers(int pid) iov.iov_len = sizeof(struct _xstate); if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) == 0) have_xstate_support = 1; +#endif } #endif
diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c index cb3c22370cf5..8af0fb5d2780 100644 --- a/arch/x86/um/user-offsets.c +++ b/arch/x86/um/user-offsets.c @@ -50,7 +50,11 @@ void foo(void) DEFINE(HOST_GS, GS); DEFINE(HOST_ORIG_AX, ORIG_EAX); #else +#if defined(PTRACE_GETREGSET) && defined(PTRACE_SETREGSET) DEFINE(HOST_FP_SIZE, sizeof(struct _xstate) / sizeof(unsigned long)); +#else + DEFINE(HOST_FP_SIZE, sizeof(struct _fpstate) / sizeof(unsigned long)); +#endif DEFINE_LONGS(HOST_BX, RBX); DEFINE_LONGS(HOST_CX, RCX); DEFINE_LONGS(HOST_DI, RDI);