Commit 86f84779 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'siginfo-linus' of... 

Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull sigingo fix from Eric Biederman:
 "The kbuild test robot found that I accidentally moved si_pkey when I
  was cleaning up siginfo_t. A short followed by an int with the int
  having 8 byte alignment. Sheesh siginfo_t is a weird structure.

  I have now corrected it and added build time checks that with a little
  luck will catch any similar future mistakes. The build time checks
  were sufficient for me to verify the bug and to verify my fix. So they
  are at least useful this once."

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal/x86: Include the field offsets in the build time checks
  signal: Correct the offset of si_pkey in struct siginfo
parents ce380619 f6a01549

arch/x86/kernel/signal_compat.c

+65 −0
Original line number Diff line number Diff line
@@ -43,6 +43,13 @@ static inline void signal_compat_build_tests(void) 
	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields) != 3 * sizeof(int));

#define CHECK_CSI_OFFSET(name)	  BUILD_BUG_ON(_sifields_offset != offsetof(compat_siginfo_t, _sifields.name))



	BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);

	BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);

	BUILD_BUG_ON(offsetof(siginfo_t, si_code)  != 8);



	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_signo) != 0);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_errno) != 4);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_code)  != 8);

	 /*

	 * Ensure that the size of each si_field never changes.

	 * If it does, it is a sign that the
@@ -63,36 +70,94 @@ static inline void signal_compat_build_tests(void) 
	CHECK_CSI_SIZE  (_kill, 2*sizeof(int));

	CHECK_SI_SIZE   (_kill, 2*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);

	BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0xC);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);



	CHECK_CSI_OFFSET(_timer);

	CHECK_CSI_SIZE  (_timer, 3*sizeof(int));

	CHECK_SI_SIZE   (_timer, 6*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_tid)     != 0x10);

	BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x14);

	BUILD_BUG_ON(offsetof(siginfo_t, si_value)   != 0x18);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_tid)     != 0x0C);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_overrun) != 0x10);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value)   != 0x14);



	CHECK_CSI_OFFSET(_rt);

	CHECK_CSI_SIZE  (_rt, 3*sizeof(int));

	CHECK_SI_SIZE   (_rt, 4*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_pid)   != 0x10);

	BUILD_BUG_ON(offsetof(siginfo_t, si_uid)   != 0x14);

	BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid)   != 0x0C);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid)   != 0x10);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);



	CHECK_CSI_OFFSET(_sigchld);

	CHECK_CSI_SIZE  (_sigchld, 5*sizeof(int));

	CHECK_SI_SIZE   (_sigchld, 8*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_pid)    != 0x10);

	BUILD_BUG_ON(offsetof(siginfo_t, si_uid)    != 0x14);

	BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x18);

	BUILD_BUG_ON(offsetof(siginfo_t, si_utime)  != 0x20);

	BUILD_BUG_ON(offsetof(siginfo_t, si_stime)  != 0x28);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid)    != 0x0C);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid)    != 0x10);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_status) != 0x14);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_utime)  != 0x18);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_stime)  != 0x1C);



#ifdef CONFIG_X86_X32_ABI

	CHECK_CSI_OFFSET(_sigchld_x32);

	CHECK_CSI_SIZE  (_sigchld_x32, 7*sizeof(int));

	/* no _sigchld_x32 in the generic siginfo_t */

	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._utime)  != 0x18);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._stime)  != 0x20);

#endif



	CHECK_CSI_OFFSET(_sigfault);

	CHECK_CSI_SIZE  (_sigfault, 4*sizeof(int));

	CHECK_SI_SIZE   (_sigfault, 8*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C);



	BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10);



	BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x20);

	BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x28);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_lower) != 0x14);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_upper) != 0x18);



	BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14);



	CHECK_CSI_OFFSET(_sigpoll);

	CHECK_CSI_SIZE  (_sigpoll, 2*sizeof(int));

	CHECK_SI_SIZE   (_sigpoll, 4*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_band)   != 0x10);

	BUILD_BUG_ON(offsetof(siginfo_t, si_fd)     != 0x18);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_band) != 0x0C);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_fd)   != 0x10);



	CHECK_CSI_OFFSET(_sigsys);

	CHECK_CSI_SIZE  (_sigsys, 3*sizeof(int));

	CHECK_SI_SIZE   (_sigsys, 4*sizeof(int));



	BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x10);

	BUILD_BUG_ON(offsetof(siginfo_t, si_syscall)   != 0x18);

	BUILD_BUG_ON(offsetof(siginfo_t, si_arch)      != 0x1C);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_call_addr) != 0x0C);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_syscall)   != 0x10);

	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_arch)      != 0x14);



	/* any new si_fields should be added here */

}

include/linux/compat.h

+2 −2
Original line number Diff line number Diff line
@@ -229,13 +229,13 @@ typedef struct compat_siginfo { 
				short int _addr_lsb;	/* Valid LSB of the reported address. */

				/* used when si_code=SEGV_BNDERR */

				struct {

					short _dummy_bnd;

					compat_uptr_t _dummy_bnd;

					compat_uptr_t _lower;

					compat_uptr_t _upper;

				} _addr_bnd;

				/* used when si_code=SEGV_PKUERR */

				struct {

					short _dummy_pkey;

					compat_uptr_t _dummy_pkey;

					u32 _pkey;

				} _addr_pkey;

			};

include/uapi/asm-generic/siginfo.h

+2 −2
Original line number Diff line number Diff line
@@ -102,13 +102,13 @@ typedef struct siginfo { 
				short _addr_lsb; /* LSB of the reported address */

				/* used when si_code=SEGV_BNDERR */

				struct {

					short _dummy_bnd;

					void *_dummy_bnd;

					void __user *_lower;

					void __user *_upper;

				} _addr_bnd;

				/* used when si_code=SEGV_PKUERR */

				struct {

					short _dummy_pkey;

					void *_dummy_pkey;

					__u32 _pkey;

				} _addr_pkey;

			};

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