On Wed, 5 May 2021 at 16:11, Eric W. Beiderman <ebiederm@xxxxxxxxxxxx> wrote: > From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> > > Don't abuse si_errno and deliver all of the perf data in _perf member > of siginfo_t. > > The data field in the perf data structures in a u64 to allow a pointer > to be encoded without needed to implement a 32bit and 64bit version of > the same structure. There already exists a 32bit and 64bit versions > siginfo_t, and the 32bit version can not include a 64bit member as it > only has 32bit alignment. So unsigned long is used in siginfo_t > instead of a u64 as unsigned long can encode a pointer on all > architectures linux supports. Since there is no functional change (we already had the unsigned long here), the explanation made me think there was a change in that area (but there wasn't). (Can leave as-is, but a "Note: " or similar if you deem it appropriate.) > v1: https://lkml.kernel.org/r/m11rarqqx2.fsf_-_@xxxxxxxxxxxxxxxxx > v2: https://lkml.kernel.org/r/20210503203814.25487-10-ebiederm@xxxxxxxxxxxx > Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Thank you! > --- > arch/arm/kernel/signal.c | 3 ++- > arch/arm64/kernel/signal.c | 3 ++- > arch/arm64/kernel/signal32.c | 3 ++- > arch/sparc/kernel/signal32.c | 3 ++- > arch/sparc/kernel/signal_64.c | 3 ++- > arch/x86/kernel/signal_compat.c | 6 ++++-- > fs/signalfd.c | 3 ++- > include/linux/compat.h | 5 ++++- > include/uapi/asm-generic/siginfo.h | 8 +++++-- > include/uapi/linux/signalfd.h | 4 ++-- > kernel/signal.c | 21 ++++++++++++------- > .../selftests/perf_events/sigtrap_threads.c | 12 +++++------ > 12 files changed, 47 insertions(+), 27 deletions(-) > > diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c > index 643bcb0f091b..f3800c0f428b 100644 > --- a/arch/arm/kernel/signal.c > +++ b/arch/arm/kernel/signal.c > @@ -757,7 +757,8 @@ static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x10); > static_assert(offsetof(siginfo_t, si_lower) == 0x14); > static_assert(offsetof(siginfo_t, si_upper) == 0x18); > static_assert(offsetof(siginfo_t, si_pkey) == 0x14); > -static_assert(offsetof(siginfo_t, si_perf) == 0x10); > +static_assert(offsetof(siginfo_t, si_perf_data) == 0x10); > +static_assert(offsetof(siginfo_t, si_perf_type) == 0x14); > static_assert(offsetof(siginfo_t, si_band) == 0x0c); > static_assert(offsetof(siginfo_t, si_fd) == 0x10); > static_assert(offsetof(siginfo_t, si_call_addr) == 0x0c); > diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c > index ad4bd27fc044..b3978b468bd4 100644 > --- a/arch/arm64/kernel/signal.c > +++ b/arch/arm64/kernel/signal.c > @@ -1005,7 +1005,8 @@ static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x18); > static_assert(offsetof(siginfo_t, si_lower) == 0x20); > static_assert(offsetof(siginfo_t, si_upper) == 0x28); > static_assert(offsetof(siginfo_t, si_pkey) == 0x20); > -static_assert(offsetof(siginfo_t, si_perf) == 0x18); > +static_assert(offsetof(siginfo_t, si_perf_data) == 0x18); > +static_assert(offsetof(siginfo_t, si_perf_type) == 0x20); > static_assert(offsetof(siginfo_t, si_band) == 0x10); > static_assert(offsetof(siginfo_t, si_fd) == 0x18); > static_assert(offsetof(siginfo_t, si_call_addr) == 0x10); > diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c > index ee6c7484e130..d3be01c46bec 100644 > --- a/arch/arm64/kernel/signal32.c > +++ b/arch/arm64/kernel/signal32.c > @@ -489,7 +489,8 @@ static_assert(offsetof(compat_siginfo_t, si_addr_lsb) == 0x10); > static_assert(offsetof(compat_siginfo_t, si_lower) == 0x14); > static_assert(offsetof(compat_siginfo_t, si_upper) == 0x18); > static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x14); > -static_assert(offsetof(compat_siginfo_t, si_perf) == 0x10); > +static_assert(offsetof(compat_siginfo_t, si_perf_data) == 0x10); > +static_assert(offsetof(compat_siginfo_t, si_perf_type) == 0x14); > static_assert(offsetof(compat_siginfo_t, si_band) == 0x0c); > static_assert(offsetof(compat_siginfo_t, si_fd) == 0x10); > static_assert(offsetof(compat_siginfo_t, si_call_addr) == 0x0c); > diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c > index 5573722e34ad..4276b9e003ca 100644 > --- a/arch/sparc/kernel/signal32.c > +++ b/arch/sparc/kernel/signal32.c > @@ -778,6 +778,7 @@ static_assert(offsetof(compat_siginfo_t, si_addr_lsb) == 0x10); > static_assert(offsetof(compat_siginfo_t, si_lower) == 0x14); > static_assert(offsetof(compat_siginfo_t, si_upper) == 0x18); > static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x14); > -static_assert(offsetof(compat_siginfo_t, si_perf) == 0x10); > +static_assert(offsetof(compat_siginfo_t, si_perf_data) == 0x10); > +static_assert(offsetof(compat_siginfo_t, si_perf_type) == 0x14); > static_assert(offsetof(compat_siginfo_t, si_band) == 0x0c); > static_assert(offsetof(compat_siginfo_t, si_fd) == 0x10); > diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c > index a69a78984c36..cea23cf95600 100644 > --- a/arch/sparc/kernel/signal_64.c > +++ b/arch/sparc/kernel/signal_64.c > @@ -588,6 +588,7 @@ static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x18); > static_assert(offsetof(siginfo_t, si_lower) == 0x20); > static_assert(offsetof(siginfo_t, si_upper) == 0x28); > static_assert(offsetof(siginfo_t, si_pkey) == 0x20); > -static_assert(offsetof(siginfo_t, si_perf) == 0x18); > +static_assert(offsetof(siginfo_t, si_perf_data) == 0x18); > +static_assert(offsetof(siginfo_t, si_perf_type) == 0x20); > static_assert(offsetof(siginfo_t, si_band) == 0x10); > static_assert(offsetof(siginfo_t, si_fd) == 0x14); > diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c > index c9601f092a1e..b52407c56000 100644 > --- a/arch/x86/kernel/signal_compat.c > +++ b/arch/x86/kernel/signal_compat.c > @@ -147,8 +147,10 @@ static inline void signal_compat_build_tests(void) > BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20); > BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14); > > - BUILD_BUG_ON(offsetof(siginfo_t, si_perf) != 0x18); > - BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf) != 0x10); > + BUILD_BUG_ON(offsetof(siginfo_t, si_perf_data) != 0x18); > + BUILD_BUG_ON(offsetof(siginfo_t, si_perf_type) != 0x20); > + BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_data) != 0x10); > + BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_type) != 0x14); > > CHECK_CSI_OFFSET(_sigpoll); > CHECK_CSI_SIZE (_sigpoll, 2*sizeof(int)); > diff --git a/fs/signalfd.c b/fs/signalfd.c > index 83130244f653..335ad39f3900 100644 > --- a/fs/signalfd.c > +++ b/fs/signalfd.c > @@ -134,7 +134,8 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, > break; > case SIL_FAULT_PERF_EVENT: > new.ssi_addr = (long) kinfo->si_addr; > - new.ssi_perf = kinfo->si_perf; > + new.ssi_perf_type = kinfo->si_perf_type; > + new.ssi_perf_data = kinfo->si_perf_data; > break; > case SIL_CHLD: > new.ssi_pid = kinfo->si_pid; > diff --git a/include/linux/compat.h b/include/linux/compat.h > index 6af7bef15e94..a27fffaae121 100644 > --- a/include/linux/compat.h > +++ b/include/linux/compat.h > @@ -236,7 +236,10 @@ typedef struct compat_siginfo { > u32 _pkey; > } _addr_pkey; > /* used when si_code=TRAP_PERF */ > - compat_ulong_t _perf; > + struct { > + compat_ulong_t _data; > + u32 _type; > + } _perf; > }; > } _sigfault; > > diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h > index 3503282021aa..3ba180f550d7 100644 > --- a/include/uapi/asm-generic/siginfo.h > +++ b/include/uapi/asm-generic/siginfo.h > @@ -96,7 +96,10 @@ union __sifields { > __u32 _pkey; > } _addr_pkey; > /* used when si_code=TRAP_PERF */ > - unsigned long _perf; > + struct { > + unsigned long _data; > + __u32 _type; > + } _perf; > }; > } _sigfault; > > @@ -159,7 +162,8 @@ typedef struct siginfo { > #define si_lower _sifields._sigfault._addr_bnd._lower > #define si_upper _sifields._sigfault._addr_bnd._upper > #define si_pkey _sifields._sigfault._addr_pkey._pkey > -#define si_perf _sifields._sigfault._perf > +#define si_perf_data _sifields._sigfault._perf._data > +#define si_perf_type _sifields._sigfault._perf._type > #define si_band _sifields._sigpoll._band > #define si_fd _sifields._sigpoll._fd > #define si_call_addr _sifields._sigsys._call_addr > diff --git a/include/uapi/linux/signalfd.h b/include/uapi/linux/signalfd.h > index 7e333042c7e3..e78dddf433fc 100644 > --- a/include/uapi/linux/signalfd.h > +++ b/include/uapi/linux/signalfd.h > @@ -39,8 +39,8 @@ struct signalfd_siginfo { > __s32 ssi_syscall; > __u64 ssi_call_addr; > __u32 ssi_arch; > - __u32 __pad3; > - __u64 ssi_perf; > + __u32 ssi_perf_type; > + __u64 ssi_perf_data; > > /* > * Pad strcture to 128 bytes. Remember to update the > diff --git a/kernel/signal.c b/kernel/signal.c > index 49560ceac048..7fec9d1c5b11 100644 > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -1758,11 +1758,13 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data) > struct kernel_siginfo info; > > clear_siginfo(&info); > - info.si_signo = SIGTRAP; > - info.si_errno = type; > - info.si_code = TRAP_PERF; > - info.si_addr = addr; > - info.si_perf = sig_data; > + info.si_signo = SIGTRAP; > + info.si_errno = 0; > + info.si_code = TRAP_PERF; > + info.si_addr = addr; > + info.si_perf_data = sig_data; > + info.si_perf_type = type; > + > return force_sig_info(&info); > } > > @@ -3380,7 +3382,8 @@ void copy_siginfo_to_external32(struct compat_siginfo *to, > break; > case SIL_FAULT_PERF_EVENT: > to->si_addr = ptr_to_compat(from->si_addr); > - to->si_perf = from->si_perf; > + to->si_perf_data = from->si_perf_data; > + to->si_perf_type = from->si_perf_type; > break; > case SIL_CHLD: > to->si_pid = from->si_pid; > @@ -3456,7 +3459,8 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to, > break; > case SIL_FAULT_PERF_EVENT: > to->si_addr = compat_ptr(from->si_addr); > - to->si_perf = from->si_perf; > + to->si_perf_data = from->si_perf_data; > + to->si_perf_type = from->si_perf_type; > break; > case SIL_CHLD: > to->si_pid = from->si_pid; > @@ -4639,7 +4643,8 @@ static inline void siginfo_buildtime_checks(void) > CHECK_OFFSET(si_lower); > CHECK_OFFSET(si_upper); > CHECK_OFFSET(si_pkey); > - CHECK_OFFSET(si_perf); > + CHECK_OFFSET(si_perf_data); > + CHECK_OFFSET(si_perf_type); > > /* sigpoll */ > CHECK_OFFSET(si_band); > diff --git a/tools/testing/selftests/perf_events/sigtrap_threads.c b/tools/testing/selftests/perf_events/sigtrap_threads.c > index 78ddf5e11625..fde123066a8c 100644 > --- a/tools/testing/selftests/perf_events/sigtrap_threads.c > +++ b/tools/testing/selftests/perf_events/sigtrap_threads.c > @@ -164,8 +164,8 @@ TEST_F(sigtrap_threads, enable_event) > EXPECT_EQ(ctx.signal_count, NUM_THREADS); > EXPECT_EQ(ctx.tids_want_signal, 0); > EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on); > - EXPECT_EQ(ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT); > - EXPECT_EQ(ctx.first_siginfo.si_perf, TEST_SIG_DATA(&ctx.iterate_on)); > + EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT); > + EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on)); > > /* Check enabled for parent. */ > ctx.iterate_on = 0; > @@ -183,8 +183,8 @@ TEST_F(sigtrap_threads, modify_and_enable_event) > EXPECT_EQ(ctx.signal_count, NUM_THREADS); > EXPECT_EQ(ctx.tids_want_signal, 0); > EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on); > - EXPECT_EQ(ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT); > - EXPECT_EQ(ctx.first_siginfo.si_perf, TEST_SIG_DATA(&ctx.iterate_on)); > + EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT); > + EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on)); > > /* Check enabled for parent. */ > ctx.iterate_on = 0; > @@ -203,8 +203,8 @@ TEST_F(sigtrap_threads, signal_stress) > EXPECT_EQ(ctx.signal_count, NUM_THREADS * ctx.iterate_on); > EXPECT_EQ(ctx.tids_want_signal, 0); > EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on); > - EXPECT_EQ(ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT); > - EXPECT_EQ(ctx.first_siginfo.si_perf, TEST_SIG_DATA(&ctx.iterate_on)); > + EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT); > + EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on)); > } > > TEST_HARNESS_MAIN > -- > 2.30.1 >
