/*
* Ptrace test TM SPR registers
*
* Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include "ptrace.h"
#include "tm.h"
/* Tracee and tracer shared data */
struct shared {
int flag;
struct tm_spr_regs regs;
};
unsigned long tfhar;
int shm_id;
struct shared *cptr, *pptr;
int shm_id1;
int *cptr1, *pptr1;
#define TM_KVM_SCHED 0xe0000001ac000001
int validate_tm_spr(struct tm_spr_regs *regs)
{
FAIL_IF(regs->tm_tfhar != tfhar);
FAIL_IF((regs->tm_texasr == TM_KVM_SCHED) && (regs->tm_tfiar != 0));
return TEST_PASS;
}
void tm_spr(void)
{
unsigned long result, texasr;
int ret;
cptr = (struct shared *)shmat(shm_id, NULL, 0);
cptr1 = (int *)shmat(shm_id1, NULL, 0);
trans:
cptr1[0] = 0;
asm __volatile__(
"1: ;"
/* TM failover handler should follow "tbegin.;" */
"mflr 31;"
"bl 4f;" /* $ = TFHAR - 12 */
"4: ;"
"mflr %[tfhar];"
"mtlr 31;"
"tbegin.;"
"beq 2f;"
"tsuspend.;"
"li 8, 1;"
"sth 8, 0(%[cptr1]);"
"tresume.;"
"b .;"
"tend.;"
"li 0, 0;"
"ori %[res], 0, 0;"
"b 3f;"
"2: ;"
"li 0, 1;"
"ori %[res], 0, 0;"
"mfspr %[texasr], %[sprn_texasr];"
"3: ;"
: [tfhar] "=r" (tfhar), [res] "=r" (result),
[texasr] "=r" (texasr), [cptr1] "=r" (cptr1)
: [sprn_texasr] "i" (SPRN_TEXASR)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r8", "r9", "r10", "r11", "r31"
);
/* There are 2 32bit instructions before tbegin. */
tfhar += 12;
if (result) {
if (!cptr->flag)
goto trans;
ret = validate_tm_spr((struct tm_spr_regs *)&cptr->regs);
shmdt((void *)cptr);
shmdt((void *)cptr1);
if (ret)
exit(1);
exit(0);
}
shmdt((void *)cptr);
shmdt((void *)cptr1);
exit(1);
}
int trace_tm_spr(pid_t child)
{
FAIL_IF(start_trace(child));
FAIL_IF(show_tm_spr(child, (struct tm_spr_regs *)&pptr->regs));
printf("TFHAR: %lx TEXASR: %lx TFIAR: %lx\n", pptr->regs.tm_tfhar,
pptr->regs.tm_texasr, pptr->regs.tm_tfiar);
pptr->flag = 1;
FAIL_IF(stop_trace(child));
return TEST_PASS;
}
int ptrace_tm_spr(void)
{
pid_t pid;
int ret, status;
SKIP_IF(!have_htm());
shm_id = shmget(IPC_PRIVATE, sizeof(struct shared), 0777|IPC_CREAT);
shm_id1 = shmget(IPC_PRIVATE, sizeof(int), 0777|IPC_CREAT);
pid = fork();
if (pid < 0) {
perror("fork() failed");
return TEST_FAIL;
}
if (pid == 0)
tm_spr();
if (pid) {
pptr = (struct shared *)shmat(shm_id, NULL, 0);
pptr1 = (int *)shmat(shm_id1, NULL, 0);
while (!pptr1[0])
asm volatile("" : : : "memory");
ret = trace_tm_spr(pid);
if (ret) {
kill(pid, SIGKILL);
shmdt((void *)pptr);
shmdt((void *)pptr1);
shmctl(shm_id, IPC_RMID, NULL);
shmctl(shm_id1, IPC_RMID, NULL);
return TEST_FAIL;
}
shmdt((void *)pptr);
shmdt((void *)pptr1);
ret = wait(&status);
shmctl(shm_id, IPC_RMID, NULL);
shmctl(shm_id1, IPC_RMID, NULL);
if (ret != pid) {
printf("Child's exit status not captured\n");
return TEST_FAIL;
}
return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
TEST_PASS;
}
return TEST_PASS;
}
int main(int argc, char *argv[])
{
return test_harness(ptrace_tm_spr, "ptrace_tm_spr");
}
mp;id=c26665ab5c49ad3e142e0f054ca3204f259ba09c'>img/Makefile
x86/microcode/intel: Drop stashed AP patch pointer optimization
This was meant to save us the scanning of the microcode containter in
the initrd since the first AP had already done that but it can also hurt
us:
Imagine a single hyperthreaded CPU (Intel(R) Atom(TM) CPU N270, for
example) which updates the microcode on the BSP but since the microcode
engine is shared between the two threads, the update on CPU1 doesn't
happen because it has already happened on CPU0 and we don't find a newer
microcode revision on CPU1.
Which doesn't set the intel_ucode_patch pointer and at initrd
jettisoning time we don't save the microcode patch for later
application.
Now, when we suspend to RAM, the loaded microcode gets cleared so we
need to reload but there's no patch saved in the cache.
Removing the optimization fixes this issue and all is fine and dandy.
Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading")
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-2-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>