> Am 24.05.2017 um 09:01 schrieb Richard Weinberger <[email protected]>: > > CC'ing Thomas. We is also facing issues with these commits. > >> Am 24.05.2017 um 03:08 schrieb Florian Fainelli: >> 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") >> Signed-off-by: Florian Fainelli <[email protected]> >> --- >> arch/x86/um/os-Linux/registers.c | 13 +++++++++---- >> arch/x86/um/user-offsets.c | 4 ++++ >> 2 files changed, 13 insertions(+), 4 deletions(-) >> >> diff --git a/arch/x86/um/os-Linux/registers.c >> b/arch/x86/um/os-Linux/registers.c >> index 00f54a91bb4b..502bd642e5c2 100644 >> --- a/arch/x86/um/os-Linux/registers.c >> +++ b/arch/x86/um/os-Linux/registers.c >> @@ -26,13 +26,14 @@ int save_i387_registers(int pid, unsigned long *fp_regs) >> >> int save_fp_registers(int pid, unsigned long *fp_regs) >> { >> - struct iovec iov; >> - >> if (have_xstate_support) { >> +#ifdef PTRACE_GETREGSET >> + struct iovec iov;
Is this okay, in C90? Won't this give an error once the thing is defined?
>> iov.iov_base = fp_regs;
>> iov.iov_len = sizeof(struct _xstate);
>> if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) < 0)
>> return -errno;
>> +#endif
>> return 0;
>> } else {
>> return save_i387_registers(pid, fp_regs);
>> @@ -48,13 +49,15 @@ int restore_i387_registers(int pid, unsigned long
>> *fp_regs)
>>
>> int restore_fp_registers(int pid, unsigned long *fp_regs)
>> {
>> - struct iovec iov;
>> -
>> if (have_xstate_support) {
>> +#ifdef PTRACE_SETREGSET
>> + struct iovec iov;
>> +
>> iov.iov_base = fp_regs;
>> iov.iov_len = sizeof(struct _xstate);
>> if (ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov) < 0)
>> return -errno;
>> +#endif
>> return 0;
>> } else {
>> return restore_i387_registers(pid, fp_regs);
>> @@ -127,8 +130,10 @@ void arch_init_registers(int pid)
>>
>> iov.iov_base = &fp_regs;
>> iov.iov_len = sizeof(struct _xstate);
>> +#ifdef PTRACE_GETREGSET
>> if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) == 0)
>> have_xstate_support = 1;
So why keep have_xstate_support when all branches that test for it are now pre
compiler conditionals?
>> +#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);
>>
smime.p7s
Description: S/MIME cryptographic signature
