perf machine: Workaround missing maps for x86 PTI entry trampolines

On x86_64 the PTI entry trampolines are not in the kernel map created by
perf tools. That results in the addresses having no symbols and prevents
annotation.  It also causes Intel PT to have decoding errors at the
trampoline addresses.

Workaround that by creating maps for the trampolines.

At present the kernel does not export information revealing where the
trampolines are.  Until that happens, the addresses are hardcoded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1526986485-6562-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter
2018-05-22 13:54:33 +03:00
committed by Arnaldo Carvalho de Melo
parent 9cecca325e
commit 4d99e41365
3 changed files with 106 additions and 5 deletions

View File

@@ -268,4 +268,7 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
*/
char *machine__resolve_kernel_addr(void *vmachine, unsigned long long *addrp, char **modp);
int machine__map_x86_64_entry_trampolines(struct machine *machine,
struct dso *kernel);
#endif /* __PERF_MACHINE_H */