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powerpc/kasan: Mark more real-mode code as not to be instrumented

PATCH Applied Paul Mackerras 2 participants 2 messages May 19, 2022 – Jun 9, 2022 PowerPC

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Paul Mackerras

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PATCH 1/1 powerpc/kasan: Mark more real-mode code as not to be instrumented

This marks more files and functions that can possibly be called in real mode as not to be instrumented by KASAN. Most were found by inspection, except for get_pseries_errorlog() which was reported as causing a crash in testing.

Reported-by Nageswara R Sastry <[email protected]>
Signed-off-by Paul Mackerras <[email protected]>
---
 arch/powerpc/kernel/Makefile            | 2 ++
 arch/powerpc/kernel/rtas.c              | 4 ++--
 arch/powerpc/kexec/crash.c              | 2 +-
 arch/powerpc/platforms/powernv/Makefile | 1 +
 4 files changed, 6 insertions(+), 3 deletions(-)
arch/powerpc/kernel/Makefile +2 -0
index e46335da7f72..e9aec39f734f 100644
@@ -37,6 +37,8 @@ KASAN_SANITIZE_paca.o := n
 KASAN_SANITIZE_setup_64.o := n
 KASAN_SANITIZE_mce.o := n
 KASAN_SANITIZE_mce_power.o := n
+KASAN_SANITIZE_udbg.o := n
+KASAN_SANITIZE_udbg_16550.o := n
 
 # we have to be particularly careful in ppc64 to exclude code that
 # runs with translations off, as we cannot access the shadow with
arch/powerpc/kernel/rtas.c +2 -2
index 733e6ef36758..dbba4ff6b8cf 100644
@@ -974,8 +974,8 @@ int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
  *
  * Return: A pointer to the specified errorlog or NULL if not found.
  */
-struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
-					      uint16_t section_id)
+noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
+						      uint16_t section_id)
 {
 	struct rtas_ext_event_log_v6 *ext_log =
 		(struct rtas_ext_event_log_v6 *)log->buffer;
arch/powerpc/kexec/crash.c +1 -1
index 22ceeeb705ab..968dbbe49f12 100644
@@ -225,7 +225,7 @@ void crash_kexec_secondary(struct pt_regs *regs)
 
 /* wait for all the CPUs to hit real mode but timeout if they don't come in */
 #if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
-static void __maybe_unused crash_kexec_wait_realmode(int cpu)
+noinstr static void __maybe_unused crash_kexec_wait_realmode(int cpu)
 {
 	unsigned int msecs;
 	int i;
arch/powerpc/platforms/powernv/Makefile +1 -0
index 6488b3842199..19f0fc5c6f1b 100644
@@ -4,6 +4,7 @@
 # in particular, idle code runs a bunch of things in real mode
 KASAN_SANITIZE_idle.o := n
 KASAN_SANITIZE_pci-ioda.o := n
+KASAN_SANITIZE_pci-ioda-tce.o := n
 # pnv_machine_check_early
 KASAN_SANITIZE_setup.o := n
Signature · 1 line
2.35.3
Applied
#1 lore raw
Quoted 6 lines · Paul Mackerras

This marks more files and functions that can possibly be called in real mode as not to be instrumented by KASAN. Most were found by inspection, except for get_pseries_errorlog() which was reported as causing a crash in testing.

Applied to powerpc/fixes.

[1/1] powerpc/kasan: Mark more real-mode code as not to be instrumented

      https://git.kernel.org/powerpc/c/743cdb7bd0f1cb32c03680c8b38257957db2e692

cheers