From e63ceebdad82f85e48b018abfc6af4ed6958179e Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 10 Mar 2021 17:57:04 +0000 Subject: powerpc/lib: Don't use __put_user_asm_goto() outside of uaccess.h __put_user_asm_goto() is internal to uaccess.h Use __put_kernel_nofault() instead. The generated code is identical. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/3e32c4f0361933909368b68f5ee569e5de661c1b.1615398498.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/code-patching.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 2333625b5e31..65aec4d6d9ba 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -21,10 +21,15 @@ static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr, struct ppc_inst *patch_addr) { - if (!ppc_inst_prefixed(instr)) - __put_user_asm_goto(ppc_inst_val(instr), patch_addr, failed, "stw"); - else - __put_user_asm_goto(ppc_inst_as_u64(instr), patch_addr, failed, "std"); + if (!ppc_inst_prefixed(instr)) { + u32 val = ppc_inst_val(instr); + + __put_kernel_nofault(patch_addr, &val, u32, failed); + } else { + u64 val = ppc_inst_as_u64(instr); + + __put_kernel_nofault(patch_addr, &val, u64, failed); + } asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr), "r" (exec_addr)); -- cgit From 164dc6ce368fa23b0aae0e5d12883fff9bf80458 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 10 Mar 2021 17:57:05 +0000 Subject: powerpc/net: Switch csum_and_copy_{to/from}_user to user_access block Use user_access_begin() instead of the might_sleep/access_ok/allow_access sequence. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/2dee286d2d6dc9a27d99e31ac564bad4fae2cb49.1615398498.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/checksum_wrappers.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/checksum_wrappers.c b/arch/powerpc/lib/checksum_wrappers.c index b895166afc82..f3999cbb2fcc 100644 --- a/arch/powerpc/lib/checksum_wrappers.c +++ b/arch/powerpc/lib/checksum_wrappers.c @@ -16,16 +16,12 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst, { __wsum csum; - might_sleep(); - - if (unlikely(!access_ok(src, len))) + if (unlikely(!user_read_access_begin(src, len))) return 0; - allow_read_from_user(src, len); - csum = csum_partial_copy_generic((void __force *)src, dst, len); - prevent_read_from_user(src, len); + user_read_access_end(); return csum; } EXPORT_SYMBOL(csum_and_copy_from_user); @@ -34,15 +30,12 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len) { __wsum csum; - might_sleep(); - if (unlikely(!access_ok(dst, len))) + if (unlikely(!user_write_access_begin(dst, len))) return 0; - allow_write_to_user(dst, len); - csum = csum_partial_copy_generic(src, (void __force *)dst, len); - prevent_write_to_user(dst, len); + user_write_access_end(); return csum; } EXPORT_SYMBOL(csum_and_copy_to_user); -- cgit From 5747230645562921b5bc19f6409f7af08fe17c6d Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 12 Mar 2021 12:50:21 +0000 Subject: powerpc/32: Remove ksp_limit ksp_limit is there to help detect stack overflows. That is specific to ppc32 as it was removed from ppc64 in commit cbc9565ee826 ("powerpc: Remove ksp_limit on ppc64"). There are other means for detecting stack overflows. As ppc64 has proven to not need it, ppc32 should be able to do without it too. Lets remove it and simplify exception handling. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d789c3385b22e07bedc997613c0d26074cb513e7.1615552866.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/sstep.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index c6aebc149d14..739ea6dc461c 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -3086,15 +3086,6 @@ NOKPROBE_SYMBOL(analyse_instr); */ static nokprobe_inline int handle_stack_update(unsigned long ea, struct pt_regs *regs) { -#ifdef CONFIG_PPC32 - /* - * Check if we will touch kernel stack overflow - */ - if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) { - printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n"); - return -EINVAL; - } -#endif /* CONFIG_PPC32 */ /* * Check if we already set since that means we'll * lose the previous value. -- cgit From 8dc7f0229b7892ccb23e19c9f30511c68cc0fdcc Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 16 Mar 2021 20:42:04 +1000 Subject: powerpc: remove partial register save logic All subarchitectures always save all GPRs to pt_regs interrupt frames now. Remove FULL_REGS and associated bits. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210316104206.407354-11-npiggin@gmail.com --- arch/powerpc/lib/sstep.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 739ea6dc461c..45bda2520755 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -1401,10 +1401,6 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, break; } - /* Following cases refer to regs->gpr[], so we need all regs */ - if (!FULL_REGS(regs)) - return -1; - rd = (word >> 21) & 0x1f; ra = (word >> 16) & 0x1f; rb = (word >> 11) & 0x1f; -- cgit From 693557ebf407a85ea400a0b501bb97687d8f4856 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 20 Apr 2021 14:02:06 +0000 Subject: powerpc/inst: ppc_inst_as_u64() becomes ppc_inst_as_ulong() In order to simplify use on PPC32, change ppc_inst_as_u64() into ppc_inst_as_ulong() that returns the 32 bits instruction on PPC32. Will be used when porting OPTPROBES to PPC32. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/22cadf29620664b600b82026d2a72b8b23351777.1618927318.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/code-patching.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 65aec4d6d9ba..870b30d9be2f 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -26,7 +26,7 @@ static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr __put_kernel_nofault(patch_addr, &val, u32, failed); } else { - u64 val = ppc_inst_as_u64(instr); + u64 val = ppc_inst_as_ulong(instr); __put_kernel_nofault(patch_addr, &val, u64, failed); } -- cgit From 6ac7897f08e04b47df3955d7691652e9d12d4068 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 14 Apr 2021 13:08:40 +0000 Subject: powerpc: Remove probe_user_read_inst() Its name comes from former probe_user_read() function. That function is now called copy_from_user_nofault(). probe_user_read_inst() uses copy_from_user_nofault() to read only a few bytes. It is suboptimal. It does the same as get_user_inst() but in addition disables page faults. But on the other hand, it is not used for the time being. So remove it for now. If one day it is really needed, we can give it a new name more in line with today's naming, and implement it using get_user_inst() Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5f6f82572242a59bfee1e19a71194d8f7ef5fca4.1618405715.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/inst.c | 31 ------------------------------- 1 file changed, 31 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c index 9cc17eb62462..c57b3548de37 100644 --- a/arch/powerpc/lib/inst.c +++ b/arch/powerpc/lib/inst.c @@ -9,24 +9,6 @@ #include #ifdef CONFIG_PPC64 -int probe_user_read_inst(struct ppc_inst *inst, - struct ppc_inst __user *nip) -{ - unsigned int val, suffix; - int err; - - err = copy_from_user_nofault(&val, nip, sizeof(val)); - if (err) - return err; - if (get_op(val) == OP_PREFIX) { - err = copy_from_user_nofault(&suffix, (void __user *)nip + 4, 4); - *inst = ppc_inst_prefix(val, suffix); - } else { - *inst = ppc_inst(val); - } - return err; -} - int probe_kernel_read_inst(struct ppc_inst *inst, struct ppc_inst *src) { @@ -45,19 +27,6 @@ int probe_kernel_read_inst(struct ppc_inst *inst, return err; } #else /* !CONFIG_PPC64 */ -int probe_user_read_inst(struct ppc_inst *inst, - struct ppc_inst __user *nip) -{ - unsigned int val; - int err; - - err = copy_from_user_nofault(&val, nip, sizeof(val)); - if (!err) - *inst = ppc_inst(val); - - return err; -} - int probe_kernel_read_inst(struct ppc_inst *inst, struct ppc_inst *src) { -- cgit From 6449078d50111c839bb7156c3b99b9def80eed42 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 14 Apr 2021 13:08:41 +0000 Subject: powerpc: Make probe_kernel_read_inst() common to PPC32 and PPC64 We have two independant versions of probe_kernel_read_inst(), one for PPC32 and one for PPC64. The PPC32 is identical to the first part of the PPC64 version. The remaining part of PPC64 version is not relevant for PPC32, but not contradictory, so we can easily have a common function with the PPC64 part opted out via a IS_ENABLED(CONFIG_PPC64). The only need is to add a version of ppc_inst_prefix() for PPC32. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/f7b9dfddef3b3760182c7e5466356c121a293dc9.1618405715.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/inst.c | 17 +---------------- 1 file changed, 1 insertion(+), 16 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c index c57b3548de37..0dff3ac2d45f 100644 --- a/arch/powerpc/lib/inst.c +++ b/arch/powerpc/lib/inst.c @@ -8,7 +8,6 @@ #include #include -#ifdef CONFIG_PPC64 int probe_kernel_read_inst(struct ppc_inst *inst, struct ppc_inst *src) { @@ -18,7 +17,7 @@ int probe_kernel_read_inst(struct ppc_inst *inst, err = copy_from_kernel_nofault(&val, src, sizeof(val)); if (err) return err; - if (get_op(val) == OP_PREFIX) { + if (IS_ENABLED(CONFIG_PPC64) && get_op(val) == OP_PREFIX) { err = copy_from_kernel_nofault(&suffix, (void *)src + 4, 4); *inst = ppc_inst_prefix(val, suffix); } else { @@ -26,17 +25,3 @@ int probe_kernel_read_inst(struct ppc_inst *inst, } return err; } -#else /* !CONFIG_PPC64 */ -int probe_kernel_read_inst(struct ppc_inst *inst, - struct ppc_inst *src) -{ - unsigned int val; - int err; - - err = copy_from_kernel_nofault(&val, src, sizeof(val)); - if (!err) - *inst = ppc_inst(val); - - return err; -} -#endif /* CONFIG_PPC64 */ -- cgit From 41d6cf68b5f611934bcc6a7d4a1a2d9bfd04b420 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 14 Apr 2021 13:08:42 +0000 Subject: powerpc: Rename probe_kernel_read_inst() When probe_kernel_read_inst() was created, it was to mimic probe_kernel_read() function. Since then, probe_kernel_read() has been renamed copy_from_kernel_nofault(). Rename probe_kernel_read_inst() into copy_inst_from_kernel_nofault(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b783d1f7cdb8914992384a669a2af57051b6bdcf.1618405715.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/inst.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c index 0dff3ac2d45f..e554d1357f2f 100644 --- a/arch/powerpc/lib/inst.c +++ b/arch/powerpc/lib/inst.c @@ -8,8 +8,7 @@ #include #include -int probe_kernel_read_inst(struct ppc_inst *inst, - struct ppc_inst *src) +int copy_inst_from_kernel_nofault(struct ppc_inst *inst, struct ppc_inst *src) { unsigned int val, suffix; int err; -- cgit From 39352430aaa05fbe4ba710231c70b334513078f2 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 14 Apr 2021 13:08:43 +0000 Subject: powerpc: Move copy_inst_from_kernel_nofault() When probe_kernel_read_inst() was created, there was no good place to put it, so a file called lib/inst.c was dedicated for it. Since then, probe_kernel_read_inst() has been renamed copy_inst_from_kernel_nofault(). And mm/maccess.h didn't exist at that time. Today, mm/maccess.h is related to copy_from_kernel_nofault(). Move copy_inst_from_kernel_nofault() into mm/maccess.c Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/9655d8957313906b77b8db5700a0e33ce06f45e5.1618405715.git.christophe.leroy@csgroup.eu --- arch/powerpc/lib/Makefile | 2 +- arch/powerpc/lib/inst.c | 26 -------------------------- 2 files changed, 1 insertion(+), 27 deletions(-) delete mode 100644 arch/powerpc/lib/inst.c (limited to 'arch/powerpc/lib') diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index d4efc182662a..f2c690ee75d1 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -16,7 +16,7 @@ CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING endif -obj-y += alloc.o code-patching.o feature-fixups.o pmem.o inst.o test_code-patching.o +obj-y += alloc.o code-patching.o feature-fixups.o pmem.o test_code-patching.o ifndef CONFIG_KASAN obj-y += string.o memcmp_$(BITS).o diff --git a/arch/powerpc/lib/inst.c b/arch/powerpc/lib/inst.c deleted file mode 100644 index e554d1357f2f..000000000000 --- a/arch/powerpc/lib/inst.c +++ /dev/null @@ -1,26 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright 2020, IBM Corporation. - */ - -#include -#include -#include -#include - -int copy_inst_from_kernel_nofault(struct ppc_inst *inst, struct ppc_inst *src) -{ - unsigned int val, suffix; - int err; - - err = copy_from_kernel_nofault(&val, src, sizeof(val)); - if (err) - return err; - if (IS_ENABLED(CONFIG_PPC64) && get_op(val) == OP_PREFIX) { - err = copy_from_kernel_nofault(&suffix, (void *)src + 4, 4); - *inst = ppc_inst_prefix(val, suffix); - } else { - *inst = ppc_inst(val); - } - return err; -} -- cgit