linux-toradex.git/arch/powerpc/net/bpf_jit_comp.c, branch v5.16

Merge tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-11-05T15:15:46+00:00

Pull powerpc updates from Michael Ellerman:

 - Enable STRICT_KERNEL_RWX for Freescale 85xx platforms.

 - Activate CONFIG_STRICT_KERNEL_RWX by default, while still allowing it
   to be disabled.

 - Add support for out-of-line static calls on 32-bit.

 - Fix oopses doing bpf-to-bpf calls when STRICT_KERNEL_RWX is enabled.

 - Fix boot hangs on e5500 due to stale value in ESR passed to
   do_page_fault().

 - Fix several bugs on pseries in handling of device tree cache
   information for hotplugged CPUs, and/or during partition migration.

 - Various other small features and fixes.

Thanks to Alexey Kardashevskiy, Alistair Popple, Anatolij Gustschin,
Andrew Donnellan, Athira Rajeev, Bixuan Cui, Bjorn Helgaas, Cédric Le
Goater, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Denis
Kirjanov, Fabiano Rosas, Frederic Barrat, Gustavo A.  R.  Silva, Hari
Bathini, Jacques de Laval, Joel Stanley, Kai Song, Kajol Jain, Laurent
Vivier, Leonardo Bras, Madhavan Srinivasan, Nathan Chancellor, Nathan
Lynch, Naveen N.  Rao, Nicholas Piggin, Nick Desaulniers, Niklas
Schnelle, Oliver O'Halloran, Rob Herring, Russell Currey, Srikar
Dronamraju, Stan Johnson, Tyrel Datwyler, Uwe Kleine-König, Vasant
Hegde, Wan Jiabing, and Xiaoming Ni,

* tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (73 commits)
  powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST
  powerpc/32e: Ignore ESR in instruction storage interrupt handler
  powerpc/powernv/prd: Unregister OPAL_MSG_PRD2 notifier during module unload
  powerpc: Don't provide __kernel_map_pages() without ARCH_SUPPORTS_DEBUG_PAGEALLOC
  MAINTAINERS: Update powerpc KVM entry
  powerpc/xmon: fix task state output
  powerpc/44x/fsp2: add missing of_node_put
  powerpc/dcr: Use cmplwi instead of 3-argument cmpli
  KVM: PPC: Tick accounting should defer vtime accounting 'til after IRQ handling
  powerpc/security: Use a mutex for interrupt exit code patching
  powerpc/83xx/mpc8349emitx: Make mcu_gpiochip_remove() return void
  powerpc/fsl_booke: Fix setting of exec flag when setting TLBCAMs
  powerpc/book3e: Fix set_memory_x() and set_memory_nx()
  powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()
  powerpc/bpf: Fix write protecting JIT code
  selftests/powerpc: Use date instead of EPOCHSECONDS in mitigation-patching.sh
  powerpc/64s/interrupt: Fix check_return_regs_valid() false positive
  powerpc/boot: Set LC_ALL=C in wrapper script
  powerpc/64s: Default to 64K pages for 64 bit book3s
  Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC"
  ...

powerpc/bpf: Fix write protecting JIT code

2021-10-27T13:08:32+00:00

Running program with bpf-to-bpf function calls results in data access
exception (0x300) with the below call trace:

  bpf_int_jit_compile+0x238/0x750 (unreliable)
  bpf_check+0x2008/0x2710
  bpf_prog_load+0xb00/0x13a0
  __sys_bpf+0x6f4/0x27c0
  sys_bpf+0x2c/0x40
  system_call_exception+0x164/0x330
  system_call_vectored_common+0xe8/0x278

as bpf_int_jit_compile() tries writing to write protected JIT code
location during the extra pass.

Fix it by holding off write protection of JIT code until the extra
pass, where branch target addresses fixup happens.

Fixes: 62e3d4210ac9 ("powerpc/bpf: Write protect JIT code")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Hari Bathini 
Reviewed-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211025055649.114728-1-hbathini@linux.ibm.com

powerpc/bpf: Validate branch ranges

2021-10-07T07:52:33+00:00

Add checks to ensure that we never emit branch instructions with
truncated branch offsets.

Suggested-by: Michael Ellerman 
Signed-off-by: Naveen N. Rao 
Tested-by: Johan Almbladh 
Reviewed-by: Christophe Leroy 
Acked-by: Song Liu 
Acked-by: Johan Almbladh 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/71d33a6b7603ec1013c9734dd8bdd4ff5e929142.1633464148.git.naveen.n.rao@linux.vnet.ibm.com

powerpc/bpf: Write protect JIT code

2021-06-21T11:13:21+00:00

Add the necessary call to bpf_jit_binary_lock_ro() to remove write and
add exec permissions to the JIT image after it has finished being
written.

Without CONFIG_STRICT_MODULE_RWX the image will be writable and
executable until the call to bpf_jit_binary_lock_ro().

Signed-off-by: Jordan Niethe 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210609013431.9805-7-jniethe5@gmail.com

powerpc/bpf: Remove bpf_jit_free()

2021-06-21T11:13:20+00:00

Commit 74451e66d516 ("bpf: make jited programs visible in traces") added
a default bpf_jit_free() implementation. Powerpc did not use the default
bpf_jit_free() as powerpc did not set the images read-only. The default
bpf_jit_free() called bpf_jit_binary_unlock_ro() is why it could not be
used for powerpc.

Commit d53d2f78cead ("bpf: Use vmalloc special flag") moved keeping
track of read-only memory to vmalloc. This included removing
bpf_jit_binary_unlock_ro(). Therefore there is no reason powerpc needs
its own bpf_jit_free(). Remove it.

Signed-off-by: Jordan Niethe 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210609013431.9805-6-jniethe5@gmail.com

powerpc/bpf: Reallocate BPF registers to volatile registers when possible on PPC32

2021-04-03T10:22:21+00:00

When the BPF routine doesn't call any function, the non volatile
registers can be reallocated to volatile registers in order to
avoid having to save them/restore on the stack.

Before this patch, the test #359 ADD default X is:

   0:	7c 64 1b 78 	mr      r4,r3
   4:	38 60 00 00 	li      r3,0
   8:	94 21 ff b0 	stwu    r1,-80(r1)
   c:	60 00 00 00 	nop
  10:	92 e1 00 2c 	stw     r23,44(r1)
  14:	93 01 00 30 	stw     r24,48(r1)
  18:	93 21 00 34 	stw     r25,52(r1)
  1c:	93 41 00 38 	stw     r26,56(r1)
  20:	39 80 00 00 	li      r12,0
  24:	39 60 00 00 	li      r11,0
  28:	3b 40 00 00 	li      r26,0
  2c:	3b 20 00 00 	li      r25,0
  30:	7c 98 23 78 	mr      r24,r4
  34:	7c 77 1b 78 	mr      r23,r3
  38:	39 80 00 42 	li      r12,66
  3c:	39 60 00 00 	li      r11,0
  40:	7d 8c d2 14 	add     r12,r12,r26
  44:	39 60 00 00 	li      r11,0
  48:	7d 83 63 78 	mr      r3,r12
  4c:	82 e1 00 2c 	lwz     r23,44(r1)
  50:	83 01 00 30 	lwz     r24,48(r1)
  54:	83 21 00 34 	lwz     r25,52(r1)
  58:	83 41 00 38 	lwz     r26,56(r1)
  5c:	38 21 00 50 	addi    r1,r1,80
  60:	4e 80 00 20 	blr

After this patch, the same test has become:

   0:	7c 64 1b 78 	mr      r4,r3
   4:	38 60 00 00 	li      r3,0
   8:	94 21 ff b0 	stwu    r1,-80(r1)
   c:	60 00 00 00 	nop
  10:	39 80 00 00 	li      r12,0
  14:	39 60 00 00 	li      r11,0
  18:	39 00 00 00 	li      r8,0
  1c:	38 e0 00 00 	li      r7,0
  20:	7c 86 23 78 	mr      r6,r4
  24:	7c 65 1b 78 	mr      r5,r3
  28:	39 80 00 42 	li      r12,66
  2c:	39 60 00 00 	li      r11,0
  30:	7d 8c 42 14 	add     r12,r12,r8
  34:	39 60 00 00 	li      r11,0
  38:	7d 83 63 78 	mr      r3,r12
  3c:	38 21 00 50 	addi    r1,r1,80
  40:	4e 80 00 20 	blr

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/b94562d7d2bb21aec89de0c40bb3cd91054b65a2.1616430991.git.christophe.leroy@csgroup.eu

powerpc/bpf: Move common functions into bpf_jit_comp.c

2021-04-03T10:22:20+00:00

Move into bpf_jit_comp.c the functions that will remain common to
PPC64 and PPC32 when we add support of EBPF for PPC32.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/2c339d77fb168ef12b213ccddfee3cb6c8ce8ae1.1616430991.git.christophe.leroy@csgroup.eu

powerpc/bpf: Remove classical BPF support for PPC32

2021-04-03T10:22:20+00:00

At the time being, PPC32 has Classical BPF support.

The test_bpf module exhibits some failure:

	test_bpf: #298 LD_IND byte frag jited:1 ret 202 != 66 FAIL (1 times)
	test_bpf: #299 LD_IND halfword frag jited:1 ret 51958 != 17220 FAIL (1 times)
	test_bpf: #301 LD_IND halfword mixed head/frag jited:1 ret 51958 != 1305 FAIL (1 times)
	test_bpf: #303 LD_ABS byte frag jited:1 ret 202 != 66 FAIL (1 times)
	test_bpf: #304 LD_ABS halfword frag jited:1 ret 51958 != 17220 FAIL (1 times)
	test_bpf: #306 LD_ABS halfword mixed head/frag jited:1 ret 51958 != 1305 FAIL (1 times)

	test_bpf: Summary: 371 PASSED, 7 FAILED, [119/366 JIT'ed]

Fixing this is not worth the effort. Instead, remove support for
classical BPF and prepare for adding Extended BPF support instead.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/fbc3e4fcc9c8f6131d6c705212530b2aa50149ee.1616430991.git.christophe.leroy@csgroup.eu

bpf, powerpc: Fix misuse of fallthrough in bpf_jit_comp()

2020-09-29T14:39:11+00:00

The user defined label following "fallthrough" is not considered by GCC
and causes build failure.

kernel-source/include/linux/compiler_attributes.h:208:41: error: attribute
'fallthrough' not preceding a case label or default label [-Werror]
 208   define fallthrough _attribute((fallthrough_))
                          ^~~~~~~~~~~~~

Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword")
Signed-off-by: He Zhe 
Signed-off-by: Daniel Borkmann 
Cc: Gustavo A. R. Silva 
Link: https://lore.kernel.org/bpf/20200928090023.38117-1-zhe.he@windriver.com

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva