From 3eb0f5193b497083391aa05d35210d5645211eef Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 17 Apr 2018 15:26:37 -0500 Subject: signal: Ensure every siginfo we send has all bits initialized Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" --- include/linux/ptrace.h | 1 - include/linux/tracehook.h | 1 + 2 files changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 919b2a0b0307..037bf0ef1ae9 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -345,7 +345,6 @@ extern void user_single_step_siginfo(struct task_struct *tsk, static inline void user_single_step_siginfo(struct task_struct *tsk, struct pt_regs *regs, siginfo_t *info) { - memset(info, 0, sizeof(*info)); info->si_signo = SIGTRAP; } #endif diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 26c152122a42..4a8841963c2e 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -124,6 +124,7 @@ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step) { if (step) { siginfo_t info; + clear_siginfo(&info); user_single_step_siginfo(current, regs, &info); force_sig_info(SIGTRAP, &info, current); return; -- cgit v1.2.3 From db78e6a0a6f9f7d7277965600eeb1a5b3a6f55a8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 17 Apr 2018 16:18:25 -0500 Subject: signal: Add TRAP_UNK si_code for undiagnosted trap exceptions Both powerpc and alpha have cases where they wronly set si_code to 0 in combination with SIGTRAP and don't mean SI_USER. About half the time this is because the architecture can not report accurately what kind of trap exception triggered the trap exception. The other half the time it looks like no one has bothered to figure out an appropriate si_code. For the cases where the architecture does not have enough information or is too lazy to figure out exactly what kind of trap exception it is define TRAP_UNK. Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-alpha@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: "Eric W. Biederman" --- include/uapi/asm-generic/siginfo.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h index 558b902f18d4..80e2a7227205 100644 --- a/include/uapi/asm-generic/siginfo.h +++ b/include/uapi/asm-generic/siginfo.h @@ -249,7 +249,8 @@ typedef struct siginfo { #define TRAP_TRACE 2 /* process trace trap */ #define TRAP_BRANCH 3 /* process taken branch trap */ #define TRAP_HWBKPT 4 /* hardware breakpoint/watchpoint */ -#define NSIGTRAP 4 +#define TRAP_UNK 5 /* undiagnosed trap */ +#define NSIGTRAP 5 /* * There is an additional set of SIGTRAP si_codes used by ptrace -- cgit v1.2.3 From 76b7f670730e87974f71df9f6129811e2769666e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 24 Apr 2018 20:48:32 -0500 Subject: signal/signalfd: Add support for SIGSYS I don't know why signalfd has never grown support for SIGSYS but grow it now. This corrects an oversight and removes a need for a default in the switch statement. Allowing gcc to warn when future members are added to the enum siginfo_layout, and signalfd does not handle them. Signed-off-by: "Eric W. Biederman" --- include/uapi/linux/signalfd.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/uapi/linux/signalfd.h b/include/uapi/linux/signalfd.h index 6f0da42fc5ef..83429a05b698 100644 --- a/include/uapi/linux/signalfd.h +++ b/include/uapi/linux/signalfd.h @@ -35,6 +35,10 @@ struct signalfd_siginfo { __u64 ssi_stime; __u64 ssi_addr; __u16 ssi_addr_lsb; + __u16 __pad2; + __s32 ssi_syscall; + __u64 ssi_call_addr; + __u32 ssi_arch; /* * Pad strcture to 128 bytes. Remember to update the @@ -45,7 +49,7 @@ struct signalfd_siginfo { * comes out of a read(2) and we really don't want to have * a compat on read(2). */ - __u8 __pad[46]; + __u8 __pad[28]; }; -- cgit v1.2.3 From 31931c93dfe05a76385a443ed28244a50e915a46 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 24 Apr 2018 20:59:47 -0500 Subject: signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR} Update the siginfo_layout function and enum siginfo_layout to represent all of the possible field layouts of struct siginfo. This allows the uses of siginfo_layout in um and arm64 where they are testing for SIL_FAULT to be more accurate as this rules out the other cases. Further this allows the switch statements on siginfo_layout to be simpler if perhaps a little more wordy. Making it easier to understand what is actually going on. As SIL_FAULT_BNDERR and SIL_FAULT_PKUERR are never expected to appear in signalfd just treat them as SIL_FAULT. To include them would take 20 extra bytes an pretty much fill up what is left of signalfd_siginfo. Signed-off-by: "Eric W. Biederman" --- include/linux/signal.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/signal.h b/include/linux/signal.h index a9bc7e1b077e..3c5200137b24 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -28,6 +28,9 @@ enum siginfo_layout { SIL_TIMER, SIL_POLL, SIL_FAULT, + SIL_FAULT_MCEERR, + SIL_FAULT_BNDERR, + SIL_FAULT_PKUERR, SIL_CHLD, SIL_RT, SIL_SYS, -- cgit v1.2.3