x86/mm/pkeys: Fix fill_sig_info_pkey (90bc9fb1) · Commits · 戴 / test

SEGV_PKUERR is a signal specific si_code which happens to have the same numeric value as several others: BUS_MCEERR_AR, ILL_ILLTRP, FPE_FLTOVF, TRAP_HWBKPT, CLD_TRAPPED, POLL_ERR, SEGV_THREAD_ID, as such it is not safe to just test the si_code the signal number must also be tested to prevent a false positive in fill_sig_info_pkey. I found this error by inspection, and BUS_MCEERR_AR appears to be a real candidate for confusion. So pass in si_signo and fix it. Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Fixes: ("x86/mm/pkeys: Fill in pkey field in siginfo") Signed-off-by:

"Eric W. Biederman" <ebiederm@xmission.com>

arch/x86/mm/fault.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -172,14 +172,15 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
		* 6. T1 : reaches here, sees vma_pkey(vma)=5, when we really
		* faulted on a pte with its pkey=4.
		*/
		static void fill_sig_info_pkey(int si_code, siginfo_t info, u32 pkey)
		static void fill_sig_info_pkey(int si_signo, int si_code, siginfo_t *info,
		u32 *pkey)
		{
		/* This is effectively an #ifdef */
		if (!boot_cpu_has(X86_FEATURE_OSPKE))
		return;

		/* Fault not from Protection Keys: nothing to do */
		if (si_code != SEGV_PKUERR)
		if ((si_code != SEGV_PKUERR) \|\| (si_signo != SIGSEGV))
		return;
		/*
		* force_sig_info_fault() is called from a number of
		@@ -218,7 +219,7 @@ force_sig_info_fault(int si_signo, int si_code, unsigned long address,
		lsb = PAGE_SHIFT;
		info.si_addr_lsb = lsb;

		fill_sig_info_pkey(si_code, &info, pkey);
		fill_sig_info_pkey(si_signo, si_code, &info, pkey);

		force_sig_info(si_signo, &info, tsk);
		}

Admin message