| Message ID | 20230824133135.1176709-3-puranjay12@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | bpf, riscv: use BPF prog pack allocator in BPF JIT | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/tree_selection | fail | Failed to apply to next/pending-fixes, riscv/for-next or riscv/master |
On Thu, Aug 24, 2023 at 6:31 AM Puranjay Mohan <puranjay12@gmail.com> wrote: > > The BPF JIT needs to write invalid instructions to RX regions of memory > to invalidate removed BPF programs. This needs a function like memset() > that can work with RX memory. > > Implement patch_text_set_nosync() which is similar to text_poke_set() of > x86. > > Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> > --- > arch/riscv/include/asm/patch.h | 1 + > arch/riscv/kernel/patch.c | 74 ++++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+) > > diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h > index 63c98833d510..aa5c1830ea43 100644 > --- a/arch/riscv/include/asm/patch.h > +++ b/arch/riscv/include/asm/patch.h > @@ -7,6 +7,7 @@ > #define _ASM_RISCV_PATCH_H > > int patch_text_nosync(void *addr, const void *insns, size_t len); > +int patch_text_set_nosync(void *addr, const int c, size_t len); > int patch_text(void *addr, u32 *insns, int ninsns); > > extern int riscv_patch_in_stop_machine; > diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c > index 465b2eebbc37..24d49999ac1a 100644 > --- a/arch/riscv/kernel/patch.c > +++ b/arch/riscv/kernel/patch.c > @@ -13,6 +13,7 @@ > #include <asm/fixmap.h> > #include <asm/ftrace.h> > #include <asm/patch.h> > +#include <asm/string.h> > > struct patch_insn { > void *addr; > @@ -53,6 +54,34 @@ static void patch_unmap(int fixmap) > } > NOKPROBE_SYMBOL(patch_unmap); > > +static int __patch_insn_set(void *addr, const int c, size_t len) > +{ > + void *waddr = addr; > + bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; > + int ret; > + > + /* > + * Only two pages can be mapped at a time for writing. > + */ > + if (len > 2 * PAGE_SIZE) > + return -EINVAL; Same for this one. [...]
Hi Puranjay, kernel test robot noticed the following build warnings: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Puranjay-Mohan/riscv-extend-patch_text_nosync-for-multiple-pages/20230824-213410 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20230824133135.1176709-3-puranjay12%40gmail.com patch subject: [PATCH bpf-next v2 2/3] riscv: implement a memset like function for text config: riscv-allnoconfig (https://download.01.org/0day-ci/archive/20230825/202308250924.NlFcBoND-lkp@intel.com/config) compiler: riscv64-linux-gcc (GCC) 13.2.0 reproduce: (https://download.01.org/0day-ci/archive/20230825/202308250924.NlFcBoND-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202308250924.NlFcBoND-lkp@intel.com/ All warnings (new ones prefixed by >>): arch/riscv/kernel/patch.c: In function '__patch_insn_set': >> arch/riscv/kernel/patch.c:61:13: warning: unused variable 'ret' [-Wunused-variable] 61 | int ret; | ^~~ vim +/ret +61 arch/riscv/kernel/patch.c 56 57 static int __patch_insn_set(void *addr, const int c, size_t len) 58 { 59 void *waddr = addr; 60 bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; > 61 int ret; 62 63 /* 64 * Only two pages can be mapped at a time for writing. 65 */ 66 if (len > 2 * PAGE_SIZE) 67 return -EINVAL; 68 69 if (across_pages) 70 patch_map(addr + PAGE_SIZE, FIX_TEXT_POKE1); 71 72 waddr = patch_map(addr, FIX_TEXT_POKE0); 73 74 memset(waddr, c, len); 75 76 patch_unmap(FIX_TEXT_POKE0); 77 78 if (across_pages) 79 patch_unmap(FIX_TEXT_POKE1); 80 81 return 0; 82 } 83 NOKPROBE_SYMBOL(__patch_insn_set); 84
On 2023/8/24 21:31, Puranjay Mohan wrote: > The BPF JIT needs to write invalid instructions to RX regions of memory > to invalidate removed BPF programs. This needs a function like memset() > that can work with RX memory. > > Implement patch_text_set_nosync() which is similar to text_poke_set() of > x86. > > Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> > --- > arch/riscv/include/asm/patch.h | 1 + > arch/riscv/kernel/patch.c | 74 ++++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+) > > diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h > index 63c98833d510..aa5c1830ea43 100644 > --- a/arch/riscv/include/asm/patch.h > +++ b/arch/riscv/include/asm/patch.h > @@ -7,6 +7,7 @@ > #define _ASM_RISCV_PATCH_H > > int patch_text_nosync(void *addr, const void *insns, size_t len); > +int patch_text_set_nosync(void *addr, const int c, size_t len); > int patch_text(void *addr, u32 *insns, int ninsns); > > extern int riscv_patch_in_stop_machine; > diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c > index 465b2eebbc37..24d49999ac1a 100644 > --- a/arch/riscv/kernel/patch.c > +++ b/arch/riscv/kernel/patch.c > @@ -13,6 +13,7 @@ > #include <asm/fixmap.h> > #include <asm/ftrace.h> > #include <asm/patch.h> > +#include <asm/string.h> > > struct patch_insn { > void *addr; > @@ -53,6 +54,34 @@ static void patch_unmap(int fixmap) > } > NOKPROBE_SYMBOL(patch_unmap); > > +static int __patch_insn_set(void *addr, const int c, size_t len) > +{ > + void *waddr = addr; > + bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; > + int ret; > + > + /* > + * Only two pages can be mapped at a time for writing. > + */ > + if (len > 2 * PAGE_SIZE) > + return -EINVAL; > + As a generic part, it better to add text_mutex lock assert. > + if (across_pages) > + patch_map(addr + PAGE_SIZE, FIX_TEXT_POKE1); > + > + waddr = patch_map(addr, FIX_TEXT_POKE0); > + > + memset(waddr, c, len); > + > + patch_unmap(FIX_TEXT_POKE0); > + > + if (across_pages) > + patch_unmap(FIX_TEXT_POKE1); > + > + return 0; > +} > +NOKPROBE_SYMBOL(__patch_insn_set); > + > static int __patch_insn_write(void *addr, const void *insn, size_t len) > { > void *waddr = addr; > @@ -95,6 +124,14 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len) > } > NOKPROBE_SYMBOL(__patch_insn_write); > #else > +static int __patch_insn_set (void *addr, const int c, size_t len) > +{ > + memset(addr, c, len); > + > + return 0; > +} > +NOKPROBE_SYMBOL(__patch_insn_set); > + > static int __patch_insn_write(void *addr, const void *insn, size_t len) > { > return copy_to_kernel_nofault(addr, insn, len); > @@ -102,6 +139,43 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len) > NOKPROBE_SYMBOL(__patch_insn_write); > #endif /* CONFIG_MMU */ > > +static int patch_insn_set(void *addr, const int c, size_t len) > +{ > + size_t patched = 0; > + size_t size; > + int ret = 0; > + > + /* > + * __patch_insn_set() can only work on 2 pages at a time so call it in a > + * loop with len <= 2 * PAGE_SIZE. > + */ > + while (patched < len && !ret) { > + size = min_t(size_t, > + PAGE_SIZE * 2 - offset_in_page(addr + patched), > + len - patched); > + ret = __patch_insn_set(addr + patched, c, size); > + > + patched += size; > + } > + > + return ret; > +} > +NOKPROBE_SYMBOL(patch_insn_set); > + > +int patch_text_set_nosync(void *addr, const int c, size_t len) > +{ > + u32 *tp = addr; > + int ret; > + > + ret = patch_insn_set(tp, c, len); > + > + if (!ret) > + flush_icache_range((uintptr_t) tp, (uintptr_t) tp + len); > + > + return ret; > +} > +NOKPROBE_SYMBOL(patch_text_set_nosync); > + > static int patch_insn_write(void *addr, const void *insn, size_t len) > { > size_t patched = 0;
Puranjay Mohan <puranjay12@gmail.com> writes: > The BPF JIT needs to write invalid instructions to RX regions of memory > to invalidate removed BPF programs. This needs a function like memset() > that can work with RX memory. > > Implement patch_text_set_nosync() which is similar to text_poke_set() of > x86. Some additional nits, in addition to the other comments (Song, kernel test bot, Lehui). > Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> > --- > arch/riscv/include/asm/patch.h | 1 + > arch/riscv/kernel/patch.c | 74 ++++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+) > > diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h > index 63c98833d510..aa5c1830ea43 100644 > --- a/arch/riscv/include/asm/patch.h > +++ b/arch/riscv/include/asm/patch.h > @@ -7,6 +7,7 @@ > #define _ASM_RISCV_PATCH_H > > int patch_text_nosync(void *addr, const void *insns, size_t len); > +int patch_text_set_nosync(void *addr, const int c, size_t len); > int patch_text(void *addr, u32 *insns, int ninsns); > > extern int riscv_patch_in_stop_machine; > diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c > index 465b2eebbc37..24d49999ac1a 100644 > --- a/arch/riscv/kernel/patch.c > +++ b/arch/riscv/kernel/patch.c > @@ -13,6 +13,7 @@ > #include <asm/fixmap.h> > #include <asm/ftrace.h> > #include <asm/patch.h> > +#include <asm/string.h> > > struct patch_insn { > void *addr; > @@ -53,6 +54,34 @@ static void patch_unmap(int fixmap) > } > NOKPROBE_SYMBOL(patch_unmap); > > +static int __patch_insn_set(void *addr, const int c, size_t len) Drop the "const" from "const int c" everywhere in this patch, and let's just use u8 instead of int. We don't need to carry the old memset() legacy argumentts! We're more modern than that! ;-) Björn
diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h index 63c98833d510..aa5c1830ea43 100644 --- a/arch/riscv/include/asm/patch.h +++ b/arch/riscv/include/asm/patch.h @@ -7,6 +7,7 @@ #define _ASM_RISCV_PATCH_H int patch_text_nosync(void *addr, const void *insns, size_t len); +int patch_text_set_nosync(void *addr, const int c, size_t len); int patch_text(void *addr, u32 *insns, int ninsns); extern int riscv_patch_in_stop_machine; diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 465b2eebbc37..24d49999ac1a 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -13,6 +13,7 @@ #include <asm/fixmap.h> #include <asm/ftrace.h> #include <asm/patch.h> +#include <asm/string.h> struct patch_insn { void *addr; @@ -53,6 +54,34 @@ static void patch_unmap(int fixmap) } NOKPROBE_SYMBOL(patch_unmap); +static int __patch_insn_set(void *addr, const int c, size_t len) +{ + void *waddr = addr; + bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; + int ret; + + /* + * Only two pages can be mapped at a time for writing. + */ + if (len > 2 * PAGE_SIZE) + return -EINVAL; + + if (across_pages) + patch_map(addr + PAGE_SIZE, FIX_TEXT_POKE1); + + waddr = patch_map(addr, FIX_TEXT_POKE0); + + memset(waddr, c, len); + + patch_unmap(FIX_TEXT_POKE0); + + if (across_pages) + patch_unmap(FIX_TEXT_POKE1); + + return 0; +} +NOKPROBE_SYMBOL(__patch_insn_set); + static int __patch_insn_write(void *addr, const void *insn, size_t len) { void *waddr = addr; @@ -95,6 +124,14 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len) } NOKPROBE_SYMBOL(__patch_insn_write); #else +static int __patch_insn_set (void *addr, const int c, size_t len) +{ + memset(addr, c, len); + + return 0; +} +NOKPROBE_SYMBOL(__patch_insn_set); + static int __patch_insn_write(void *addr, const void *insn, size_t len) { return copy_to_kernel_nofault(addr, insn, len); @@ -102,6 +139,43 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len) NOKPROBE_SYMBOL(__patch_insn_write); #endif /* CONFIG_MMU */ +static int patch_insn_set(void *addr, const int c, size_t len) +{ + size_t patched = 0; + size_t size; + int ret = 0; + + /* + * __patch_insn_set() can only work on 2 pages at a time so call it in a + * loop with len <= 2 * PAGE_SIZE. + */ + while (patched < len && !ret) { + size = min_t(size_t, + PAGE_SIZE * 2 - offset_in_page(addr + patched), + len - patched); + ret = __patch_insn_set(addr + patched, c, size); + + patched += size; + } + + return ret; +} +NOKPROBE_SYMBOL(patch_insn_set); + +int patch_text_set_nosync(void *addr, const int c, size_t len) +{ + u32 *tp = addr; + int ret; + + ret = patch_insn_set(tp, c, len); + + if (!ret) + flush_icache_range((uintptr_t) tp, (uintptr_t) tp + len); + + return ret; +} +NOKPROBE_SYMBOL(patch_text_set_nosync); + static int patch_insn_write(void *addr, const void *insn, size_t len) { size_t patched = 0;
The BPF JIT needs to write invalid instructions to RX regions of memory to invalidate removed BPF programs. This needs a function like memset() that can work with RX memory. Implement patch_text_set_nosync() which is similar to text_poke_set() of x86. Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> --- arch/riscv/include/asm/patch.h | 1 + arch/riscv/kernel/patch.c | 74 ++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+)