* [PATCH v4 0/2] Fix binfmt_flat loader for RISC-V @ 2021-04-17 1:10 Damien Le Moal 2021-04-17 1:10 ` [PATCH v4 1/2] binfmt_flat: allow not offsetting data start Damien Le Moal 2021-04-17 1:10 ` [PATCH v4 2/2] riscv: Disable data start offset in flat binaries Damien Le Moal 0 siblings, 2 replies; 11+ messages in thread From: Damien Le Moal @ 2021-04-17 1:10 UTC (permalink / raw) To: uclinux-dev, Greg Ungerer, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig RISC-V NOMMU flat binaries cannot tolerate a gap between the text and data section as the toolchain fully resolves at compile time the PC relative global pointer (__global_pointer$ value loaded in the gp register). Without a relocation entry provided, the flat bin loader cannot fix the value if a gap is introduced and user executables fail to run. This series fixes this problem by allowing an architecture to request the flat loader to suppress the offset of the data start section. Combined with the use of elf2flt "-r" option to mark the flat executables with the FLAT_FLAG_RAM flag, the text and data sections are loaded contiguously in memory, without a change in their relative position from compile time. The first patch fixes binfmt_flat flat_load_file() using the new configuration option CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. The second patch enables this new option for RISCV NOMMU builds. These patches do not change the binfmt_flat loader behavior for other architectures. Changes from v3: * Renamed the configuration option from CONFIG_BINFMT_FLAT_NO_TEXT_DATA_GAP to CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET to clarify that only the offseting of the data section start is suppressed. * Do not force loding to RAM (contiguously) if the flat binary does not have the FLAT_FLAG_RAM flag set. * Updated commit messages to reflect above changes. Changes from v2: * Updated distribution list * Added Palmer ack-by tag Changes from v1: * Replace FLAT_TEXT_DATA_NO_GAP macro with CONFIG_BINFMT_FLAT_NO_TEXT_DATA_GAP config option (patch 1). * Remove the addition of riscv/include/asm/flat.h and set CONFIG_BINFMT_FLAT_NO_TEXT_DATA_GAP for RISCV and !MMU Damien Le Moal (2): binfmt_flat: allow not offsetting data start riscv: Disable data start offset in flat binaries arch/riscv/Kconfig | 1 + fs/Kconfig.binfmt | 3 +++ fs/binfmt_flat.c | 19 ++++++++++++++----- 3 files changed, 18 insertions(+), 5 deletions(-) -- 2.30.2 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-17 1:10 [PATCH v4 0/2] Fix binfmt_flat loader for RISC-V Damien Le Moal @ 2021-04-17 1:10 ` Damien Le Moal 2021-04-17 4:52 ` Greg Ungerer 2021-04-17 1:10 ` [PATCH v4 2/2] riscv: Disable data start offset in flat binaries Damien Le Moal 1 sibling, 1 reply; 11+ messages in thread From: Damien Le Moal @ 2021-04-17 1:10 UTC (permalink / raw) To: uclinux-dev, Greg Ungerer, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset the data start"") restored offsetting the start of the data section by a number of words defined by MAX_SHARED_LIBS. As a result, since MAX_SHARED_LIBS is never 0, a gap between the text and data sections always exists. For architectures which cannot support a such gap between the text and data sections (e.g. riscv nommu), flat binary programs cannot be executed. To allow an architecture to request no data start offset to allow for contiguous text and data sections for binaries flagged with FLAT_FLAG_RAM, introduce the new config option CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c to MAX_SHARED_LIBS for architectures tolerating or needing the data start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the data section length and start position. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> --- fs/Kconfig.binfmt | 3 +++ fs/binfmt_flat.c | 19 ++++++++++++++----- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt index c6f1c8c1934e..06fb7a93a1bd 100644 --- a/fs/Kconfig.binfmt +++ b/fs/Kconfig.binfmt @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK config BINFMT_FLAT_OLD_ALWAYS_RAM bool +config BINFMT_FLAT_NO_DATA_START_OFFSET + bool + config BINFMT_FLAT_OLD bool "Enable support for very old legacy flat binaries" depends on BINFMT_FLAT diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index b9c658e0548e..1dc68dfba3e0 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -74,6 +74,12 @@ #define MAX_SHARED_LIBS (1) #endif +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET +#define DATA_START_OFFSET_WORDS (0) +#else +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) +#endif + struct lib_info { struct { unsigned long start_code; /* Start of text segment */ @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, * it all together. */ if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { + /* * this should give us a ROM ptr, but if it doesn't we don't * really care @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, goto err; } - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); + len = data_len + extra + + DATA_START_OFFSET_WORDS * sizeof(unsigned long); len = PAGE_ALIGN(len); realdatastart = vm_mmap(NULL, 0, len, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, goto err; } datapos = ALIGN(realdatastart + - MAX_SHARED_LIBS * sizeof(unsigned long), + DATA_START_OFFSET_WORDS * sizeof(unsigned long), FLAT_DATA_ALIGN); pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, memp_size = len; } else { - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); + len = text_len + data_len + extra + + DATA_START_OFFSET_WORDS * sizeof(u32); len = PAGE_ALIGN(len); textpos = vm_mmap(NULL, 0, len, PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, realdatastart = textpos + ntohl(hdr->data_start); datapos = ALIGN(realdatastart + - MAX_SHARED_LIBS * sizeof(u32), + DATA_START_OFFSET_WORDS * sizeof(u32), FLAT_DATA_ALIGN); reloc = (__be32 __user *) @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, ret = result; pr_err("Unable to read code+data+bss, errno %d\n", ret); vm_munmap(textpos, text_len + data_len + extra + - MAX_SHARED_LIBS * sizeof(u32)); + DATA_START_OFFSET_WORDS * sizeof(u32)); goto err; } } -- 2.30.2 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-17 1:10 ` [PATCH v4 1/2] binfmt_flat: allow not offsetting data start Damien Le Moal @ 2021-04-17 4:52 ` Greg Ungerer 2021-04-17 4:54 ` Damien Le Moal 0 siblings, 1 reply; 11+ messages in thread From: Greg Ungerer @ 2021-04-17 4:52 UTC (permalink / raw) To: Damien Le Moal, uclinux-dev, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig On 17/4/21 11:10 am, Damien Le Moal wrote: > Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset > the data start"") restored offsetting the start of the data section by > a number of words defined by MAX_SHARED_LIBS. As a result, since > MAX_SHARED_LIBS is never 0, a gap between the text and data sections > always exists. For architectures which cannot support a such gap > between the text and data sections (e.g. riscv nommu), flat binary > programs cannot be executed. > > To allow an architecture to request no data start offset to allow for > contiguous text and data sections for binaries flagged with > FLAT_FLAG_RAM, introduce the new config option > CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the > macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c > to MAX_SHARED_LIBS for architectures tolerating or needing the data > start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) > and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. > DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the > data section length and start position. > > Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> > --- > fs/Kconfig.binfmt | 3 +++ > fs/binfmt_flat.c | 19 ++++++++++++++----- > 2 files changed, 17 insertions(+), 5 deletions(-) > > diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt > index c6f1c8c1934e..06fb7a93a1bd 100644 > --- a/fs/Kconfig.binfmt > +++ b/fs/Kconfig.binfmt > @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK > config BINFMT_FLAT_OLD_ALWAYS_RAM > bool > > +config BINFMT_FLAT_NO_DATA_START_OFFSET > + bool > + > config BINFMT_FLAT_OLD > bool "Enable support for very old legacy flat binaries" > depends on BINFMT_FLAT > diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c > index b9c658e0548e..1dc68dfba3e0 100644 > --- a/fs/binfmt_flat.c > +++ b/fs/binfmt_flat.c > @@ -74,6 +74,12 @@ > #define MAX_SHARED_LIBS (1) > #endif > > +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET > +#define DATA_START_OFFSET_WORDS (0) > +#else > +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) > +#endif > + > struct lib_info { > struct { > unsigned long start_code; /* Start of text segment */ > @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, > * it all together. > */ > if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { > + Random white space change... Don't worry about re-spinning though, I will just edit this chunk out. > /* > * this should give us a ROM ptr, but if it doesn't we don't > * really care > @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, > goto err; > } > > - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); > + len = data_len + extra + > + DATA_START_OFFSET_WORDS * sizeof(unsigned long); > len = PAGE_ALIGN(len); > realdatastart = vm_mmap(NULL, 0, len, > PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); > @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, > goto err; > } > datapos = ALIGN(realdatastart + > - MAX_SHARED_LIBS * sizeof(unsigned long), > + DATA_START_OFFSET_WORDS * sizeof(unsigned long), > FLAT_DATA_ALIGN); > > pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", > @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, > memp_size = len; > } else { > > - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); > + len = text_len + data_len + extra + > + DATA_START_OFFSET_WORDS * sizeof(u32); > len = PAGE_ALIGN(len); > textpos = vm_mmap(NULL, 0, len, > PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); > @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, > > realdatastart = textpos + ntohl(hdr->data_start); > datapos = ALIGN(realdatastart + > - MAX_SHARED_LIBS * sizeof(u32), > + DATA_START_OFFSET_WORDS * sizeof(u32), > FLAT_DATA_ALIGN); > > reloc = (__be32 __user *) > @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, > ret = result; > pr_err("Unable to read code+data+bss, errno %d\n", ret); > vm_munmap(textpos, text_len + data_len + extra + > - MAX_SHARED_LIBS * sizeof(u32)); > + DATA_START_OFFSET_WORDS * sizeof(u32)); > goto err; > } > } > Thanks, otherwise looks good. Acked-by: Greg Ungerer <gerg@linux-m68k.org> I will push this into my m68knommu tree, for-next branch. I just carry the flat format changes in that tree now to make my life easier. Regards Greg _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-17 4:52 ` Greg Ungerer @ 2021-04-17 4:54 ` Damien Le Moal 2021-04-18 2:38 ` Greg Ungerer 0 siblings, 1 reply; 11+ messages in thread From: Damien Le Moal @ 2021-04-17 4:54 UTC (permalink / raw) To: Greg Ungerer, uclinux-dev, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig On 2021/04/17 13:52, Greg Ungerer wrote: > > On 17/4/21 11:10 am, Damien Le Moal wrote: >> Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset >> the data start"") restored offsetting the start of the data section by >> a number of words defined by MAX_SHARED_LIBS. As a result, since >> MAX_SHARED_LIBS is never 0, a gap between the text and data sections >> always exists. For architectures which cannot support a such gap >> between the text and data sections (e.g. riscv nommu), flat binary >> programs cannot be executed. >> >> To allow an architecture to request no data start offset to allow for >> contiguous text and data sections for binaries flagged with >> FLAT_FLAG_RAM, introduce the new config option >> CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the >> macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c >> to MAX_SHARED_LIBS for architectures tolerating or needing the data >> start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) >> and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. >> DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the >> data section length and start position. >> >> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> >> --- >> fs/Kconfig.binfmt | 3 +++ >> fs/binfmt_flat.c | 19 ++++++++++++++----- >> 2 files changed, 17 insertions(+), 5 deletions(-) >> >> diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt >> index c6f1c8c1934e..06fb7a93a1bd 100644 >> --- a/fs/Kconfig.binfmt >> +++ b/fs/Kconfig.binfmt >> @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK >> config BINFMT_FLAT_OLD_ALWAYS_RAM >> bool >> >> +config BINFMT_FLAT_NO_DATA_START_OFFSET >> + bool >> + >> config BINFMT_FLAT_OLD >> bool "Enable support for very old legacy flat binaries" >> depends on BINFMT_FLAT >> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >> index b9c658e0548e..1dc68dfba3e0 100644 >> --- a/fs/binfmt_flat.c >> +++ b/fs/binfmt_flat.c >> @@ -74,6 +74,12 @@ >> #define MAX_SHARED_LIBS (1) >> #endif >> >> +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET >> +#define DATA_START_OFFSET_WORDS (0) >> +#else >> +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) >> +#endif >> + >> struct lib_info { >> struct { >> unsigned long start_code; /* Start of text segment */ >> @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, >> * it all together. >> */ >> if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { >> + > > Random white space change... > Don't worry about re-spinning though, I will just edit this chunk out. Oops. Sorry about that. I should have better checked :) > > >> /* >> * this should give us a ROM ptr, but if it doesn't we don't >> * really care >> @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, >> goto err; >> } >> >> - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); >> + len = data_len + extra + >> + DATA_START_OFFSET_WORDS * sizeof(unsigned long); >> len = PAGE_ALIGN(len); >> realdatastart = vm_mmap(NULL, 0, len, >> PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); >> @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, >> goto err; >> } >> datapos = ALIGN(realdatastart + >> - MAX_SHARED_LIBS * sizeof(unsigned long), >> + DATA_START_OFFSET_WORDS * sizeof(unsigned long), >> FLAT_DATA_ALIGN); >> >> pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", >> @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, >> memp_size = len; >> } else { >> >> - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); >> + len = text_len + data_len + extra + >> + DATA_START_OFFSET_WORDS * sizeof(u32); >> len = PAGE_ALIGN(len); >> textpos = vm_mmap(NULL, 0, len, >> PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); >> @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, >> >> realdatastart = textpos + ntohl(hdr->data_start); >> datapos = ALIGN(realdatastart + >> - MAX_SHARED_LIBS * sizeof(u32), >> + DATA_START_OFFSET_WORDS * sizeof(u32), >> FLAT_DATA_ALIGN); >> >> reloc = (__be32 __user *) >> @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, >> ret = result; >> pr_err("Unable to read code+data+bss, errno %d\n", ret); >> vm_munmap(textpos, text_len + data_len + extra + >> - MAX_SHARED_LIBS * sizeof(u32)); >> + DATA_START_OFFSET_WORDS * sizeof(u32)); >> goto err; >> } >> } >> > > Thanks, otherwise looks good. > > Acked-by: Greg Ungerer <gerg@linux-m68k.org> > > I will push this into my m68knommu tree, for-next branch. > I just carry the flat format changes in that tree now to make my life easier. Great. Thanks ! Are you taking both patches or should Plamer take the riscv Kconfig change through his tree ? > > Regards > Greg > > -- Damien Le Moal Western Digital Research _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-17 4:54 ` Damien Le Moal @ 2021-04-18 2:38 ` Greg Ungerer 2021-04-22 12:00 ` Damien Le Moal 0 siblings, 1 reply; 11+ messages in thread From: Greg Ungerer @ 2021-04-18 2:38 UTC (permalink / raw) To: Damien Le Moal, uclinux-dev, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig On 17/4/21 2:54 pm, Damien Le Moal wrote: > On 2021/04/17 13:52, Greg Ungerer wrote: >> >> On 17/4/21 11:10 am, Damien Le Moal wrote: >>> Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset >>> the data start"") restored offsetting the start of the data section by >>> a number of words defined by MAX_SHARED_LIBS. As a result, since >>> MAX_SHARED_LIBS is never 0, a gap between the text and data sections >>> always exists. For architectures which cannot support a such gap >>> between the text and data sections (e.g. riscv nommu), flat binary >>> programs cannot be executed. >>> >>> To allow an architecture to request no data start offset to allow for >>> contiguous text and data sections for binaries flagged with >>> FLAT_FLAG_RAM, introduce the new config option >>> CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the >>> macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c >>> to MAX_SHARED_LIBS for architectures tolerating or needing the data >>> start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) >>> and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. >>> DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the >>> data section length and start position. >>> >>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> >>> --- >>> fs/Kconfig.binfmt | 3 +++ >>> fs/binfmt_flat.c | 19 ++++++++++++++----- >>> 2 files changed, 17 insertions(+), 5 deletions(-) >>> >>> diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt >>> index c6f1c8c1934e..06fb7a93a1bd 100644 >>> --- a/fs/Kconfig.binfmt >>> +++ b/fs/Kconfig.binfmt >>> @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK >>> config BINFMT_FLAT_OLD_ALWAYS_RAM >>> bool >>> >>> +config BINFMT_FLAT_NO_DATA_START_OFFSET >>> + bool >>> + >>> config BINFMT_FLAT_OLD >>> bool "Enable support for very old legacy flat binaries" >>> depends on BINFMT_FLAT >>> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >>> index b9c658e0548e..1dc68dfba3e0 100644 >>> --- a/fs/binfmt_flat.c >>> +++ b/fs/binfmt_flat.c >>> @@ -74,6 +74,12 @@ >>> #define MAX_SHARED_LIBS (1) >>> #endif >>> >>> +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET >>> +#define DATA_START_OFFSET_WORDS (0) >>> +#else >>> +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) >>> +#endif >>> + >>> struct lib_info { >>> struct { >>> unsigned long start_code; /* Start of text segment */ >>> @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>> * it all together. >>> */ >>> if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { >>> + >> >> Random white space change... >> Don't worry about re-spinning though, I will just edit this chunk out. > > Oops. Sorry about that. I should have better checked :) > >> >> >>> /* >>> * this should give us a ROM ptr, but if it doesn't we don't >>> * really care >>> @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>> goto err; >>> } >>> >>> - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); >>> + len = data_len + extra + >>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long); >>> len = PAGE_ALIGN(len); >>> realdatastart = vm_mmap(NULL, 0, len, >>> PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); >>> @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>> goto err; >>> } >>> datapos = ALIGN(realdatastart + >>> - MAX_SHARED_LIBS * sizeof(unsigned long), >>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long), >>> FLAT_DATA_ALIGN); >>> >>> pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", >>> @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>> memp_size = len; >>> } else { >>> >>> - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); >>> + len = text_len + data_len + extra + >>> + DATA_START_OFFSET_WORDS * sizeof(u32); >>> len = PAGE_ALIGN(len); >>> textpos = vm_mmap(NULL, 0, len, >>> PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); >>> @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>> >>> realdatastart = textpos + ntohl(hdr->data_start); >>> datapos = ALIGN(realdatastart + >>> - MAX_SHARED_LIBS * sizeof(u32), >>> + DATA_START_OFFSET_WORDS * sizeof(u32), >>> FLAT_DATA_ALIGN); >>> >>> reloc = (__be32 __user *) >>> @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>> ret = result; >>> pr_err("Unable to read code+data+bss, errno %d\n", ret); >>> vm_munmap(textpos, text_len + data_len + extra + >>> - MAX_SHARED_LIBS * sizeof(u32)); >>> + DATA_START_OFFSET_WORDS * sizeof(u32)); >>> goto err; >>> } >>> } >>> >> >> Thanks, otherwise looks good. >> >> Acked-by: Greg Ungerer <gerg@linux-m68k.org> >> >> I will push this into my m68knommu tree, for-next branch. >> I just carry the flat format changes in that tree now to make my life easier. > > Great. Thanks ! > Are you taking both patches or should Plamer take the riscv Kconfig change > through his tree ? I am happy to take both. Palmer? Regards Greg _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-18 2:38 ` Greg Ungerer @ 2021-04-22 12:00 ` Damien Le Moal 2021-04-23 4:04 ` Palmer Dabbelt 0 siblings, 1 reply; 11+ messages in thread From: Damien Le Moal @ 2021-04-22 12:00 UTC (permalink / raw) To: Greg Ungerer, uclinux-dev, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig On 2021/04/18 11:38, Greg Ungerer wrote: > > > On 17/4/21 2:54 pm, Damien Le Moal wrote: >> On 2021/04/17 13:52, Greg Ungerer wrote: >>> >>> On 17/4/21 11:10 am, Damien Le Moal wrote: >>>> Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset >>>> the data start"") restored offsetting the start of the data section by >>>> a number of words defined by MAX_SHARED_LIBS. As a result, since >>>> MAX_SHARED_LIBS is never 0, a gap between the text and data sections >>>> always exists. For architectures which cannot support a such gap >>>> between the text and data sections (e.g. riscv nommu), flat binary >>>> programs cannot be executed. >>>> >>>> To allow an architecture to request no data start offset to allow for >>>> contiguous text and data sections for binaries flagged with >>>> FLAT_FLAG_RAM, introduce the new config option >>>> CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the >>>> macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c >>>> to MAX_SHARED_LIBS for architectures tolerating or needing the data >>>> start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) >>>> and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. >>>> DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the >>>> data section length and start position. >>>> >>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> >>>> --- >>>> fs/Kconfig.binfmt | 3 +++ >>>> fs/binfmt_flat.c | 19 ++++++++++++++----- >>>> 2 files changed, 17 insertions(+), 5 deletions(-) >>>> >>>> diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt >>>> index c6f1c8c1934e..06fb7a93a1bd 100644 >>>> --- a/fs/Kconfig.binfmt >>>> +++ b/fs/Kconfig.binfmt >>>> @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK >>>> config BINFMT_FLAT_OLD_ALWAYS_RAM >>>> bool >>>> >>>> +config BINFMT_FLAT_NO_DATA_START_OFFSET >>>> + bool >>>> + >>>> config BINFMT_FLAT_OLD >>>> bool "Enable support for very old legacy flat binaries" >>>> depends on BINFMT_FLAT >>>> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >>>> index b9c658e0548e..1dc68dfba3e0 100644 >>>> --- a/fs/binfmt_flat.c >>>> +++ b/fs/binfmt_flat.c >>>> @@ -74,6 +74,12 @@ >>>> #define MAX_SHARED_LIBS (1) >>>> #endif >>>> >>>> +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET >>>> +#define DATA_START_OFFSET_WORDS (0) >>>> +#else >>>> +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) >>>> +#endif >>>> + >>>> struct lib_info { >>>> struct { >>>> unsigned long start_code; /* Start of text segment */ >>>> @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>> * it all together. >>>> */ >>>> if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { >>>> + >>> >>> Random white space change... >>> Don't worry about re-spinning though, I will just edit this chunk out. >> >> Oops. Sorry about that. I should have better checked :) >> >>> >>> >>>> /* >>>> * this should give us a ROM ptr, but if it doesn't we don't >>>> * really care >>>> @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>> goto err; >>>> } >>>> >>>> - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); >>>> + len = data_len + extra + >>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long); >>>> len = PAGE_ALIGN(len); >>>> realdatastart = vm_mmap(NULL, 0, len, >>>> PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); >>>> @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>> goto err; >>>> } >>>> datapos = ALIGN(realdatastart + >>>> - MAX_SHARED_LIBS * sizeof(unsigned long), >>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long), >>>> FLAT_DATA_ALIGN); >>>> >>>> pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", >>>> @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>> memp_size = len; >>>> } else { >>>> >>>> - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); >>>> + len = text_len + data_len + extra + >>>> + DATA_START_OFFSET_WORDS * sizeof(u32); >>>> len = PAGE_ALIGN(len); >>>> textpos = vm_mmap(NULL, 0, len, >>>> PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); >>>> @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>> >>>> realdatastart = textpos + ntohl(hdr->data_start); >>>> datapos = ALIGN(realdatastart + >>>> - MAX_SHARED_LIBS * sizeof(u32), >>>> + DATA_START_OFFSET_WORDS * sizeof(u32), >>>> FLAT_DATA_ALIGN); >>>> >>>> reloc = (__be32 __user *) >>>> @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>> ret = result; >>>> pr_err("Unable to read code+data+bss, errno %d\n", ret); >>>> vm_munmap(textpos, text_len + data_len + extra + >>>> - MAX_SHARED_LIBS * sizeof(u32)); >>>> + DATA_START_OFFSET_WORDS * sizeof(u32)); >>>> goto err; >>>> } >>>> } >>>> >>> >>> Thanks, otherwise looks good. >>> >>> Acked-by: Greg Ungerer <gerg@linux-m68k.org> >>> >>> I will push this into my m68knommu tree, for-next branch. >>> I just carry the flat format changes in that tree now to make my life easier. >> >> Great. Thanks ! >> Are you taking both patches or should Plamer take the riscv Kconfig change >> through his tree ? > > I am happy to take both. > Palmer? Palmer, Ping ! -- Damien Le Moal Western Digital Research _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-22 12:00 ` Damien Le Moal @ 2021-04-23 4:04 ` Palmer Dabbelt 2021-04-23 5:38 ` Greg Ungerer 0 siblings, 1 reply; 11+ messages in thread From: Palmer Dabbelt @ 2021-04-23 4:04 UTC (permalink / raw) To: Damien Le Moal Cc: gerg, uclinux-dev, linux-riscv, linux-kernel, Anup Patel, Christoph Hellwig On Thu, 22 Apr 2021 05:00:32 PDT (-0700), Damien Le Moal wrote: >> On 2021/04/18 11:38, Greg Ungerer wrote: >> >> >> On 17/4/21 2:54 pm, Damien Le Moal wrote: >>> On 2021/04/17 13:52, Greg Ungerer wrote: >>>> >>>> On 17/4/21 11:10 am, Damien Le Moal wrote: >>>>> Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset >>>>> the data start"") restored offsetting the start of the data section by >>>>> a number of words defined by MAX_SHARED_LIBS. As a result, since >>>>> MAX_SHARED_LIBS is never 0, a gap between the text and data sections >>>>> always exists. For architectures which cannot support a such gap >>>>> between the text and data sections (e.g. riscv nommu), flat binary >>>>> programs cannot be executed. >>>>> >>>>> To allow an architecture to request no data start offset to allow for >>>>> contiguous text and data sections for binaries flagged with >>>>> FLAT_FLAG_RAM, introduce the new config option >>>>> CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the >>>>> macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c >>>>> to MAX_SHARED_LIBS for architectures tolerating or needing the data >>>>> start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) >>>>> and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. >>>>> DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the >>>>> data section length and start position. >>>>> >>>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> >>>>> --- >>>>> fs/Kconfig.binfmt | 3 +++ >>>>> fs/binfmt_flat.c | 19 ++++++++++++++----- >>>>> 2 files changed, 17 insertions(+), 5 deletions(-) >>>>> >>>>> diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt >>>>> index c6f1c8c1934e..06fb7a93a1bd 100644 >>>>> --- a/fs/Kconfig.binfmt >>>>> +++ b/fs/Kconfig.binfmt >>>>> @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK >>>>> config BINFMT_FLAT_OLD_ALWAYS_RAM >>>>> bool >>>>> >>>>> +config BINFMT_FLAT_NO_DATA_START_OFFSET >>>>> + bool >>>>> + >>>>> config BINFMT_FLAT_OLD >>>>> bool "Enable support for very old legacy flat binaries" >>>>> depends on BINFMT_FLAT >>>>> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >>>>> index b9c658e0548e..1dc68dfba3e0 100644 >>>>> --- a/fs/binfmt_flat.c >>>>> +++ b/fs/binfmt_flat.c >>>>> @@ -74,6 +74,12 @@ >>>>> #define MAX_SHARED_LIBS (1) >>>>> #endif >>>>> >>>>> +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET >>>>> +#define DATA_START_OFFSET_WORDS (0) >>>>> +#else >>>>> +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) >>>>> +#endif >>>>> + >>>>> struct lib_info { >>>>> struct { >>>>> unsigned long start_code; /* Start of text segment */ >>>>> @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>> * it all together. >>>>> */ >>>>> if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { >>>>> + >>>> >>>> Random white space change... >>>> Don't worry about re-spinning though, I will just edit this chunk out. >>> >>> Oops. Sorry about that. I should have better checked :) >>> >>>> >>>> >>>>> /* >>>>> * this should give us a ROM ptr, but if it doesn't we don't >>>>> * really care >>>>> @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>> goto err; >>>>> } >>>>> >>>>> - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); >>>>> + len = data_len + extra + >>>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long); >>>>> len = PAGE_ALIGN(len); >>>>> realdatastart = vm_mmap(NULL, 0, len, >>>>> PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); >>>>> @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>> goto err; >>>>> } >>>>> datapos = ALIGN(realdatastart + >>>>> - MAX_SHARED_LIBS * sizeof(unsigned long), >>>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long), >>>>> FLAT_DATA_ALIGN); >>>>> >>>>> pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", >>>>> @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>> memp_size = len; >>>>> } else { >>>>> >>>>> - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); >>>>> + len = text_len + data_len + extra + >>>>> + DATA_START_OFFSET_WORDS * sizeof(u32); >>>>> len = PAGE_ALIGN(len); >>>>> textpos = vm_mmap(NULL, 0, len, >>>>> PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); >>>>> @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>> >>>>> realdatastart = textpos + ntohl(hdr->data_start); >>>>> datapos = ALIGN(realdatastart + >>>>> - MAX_SHARED_LIBS * sizeof(u32), >>>>> + DATA_START_OFFSET_WORDS * sizeof(u32), >>>>> FLAT_DATA_ALIGN); >>>>> >>>>> reloc = (__be32 __user *) >>>>> @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>> ret = result; >>>>> pr_err("Unable to read code+data+bss, errno %d\n", ret); >>>>> vm_munmap(textpos, text_len + data_len + extra + >>>>> - MAX_SHARED_LIBS * sizeof(u32)); >>>>> + DATA_START_OFFSET_WORDS * sizeof(u32)); >>>>> goto err; >>>>> } >>>>> } >>>>> >>>> >>>> Thanks, otherwise looks good. >>>> >>>> Acked-by: Greg Ungerer <gerg@linux-m68k.org> >>>> >>>> I will push this into my m68knommu tree, for-next branch. >>>> I just carry the flat format changes in that tree now to make my life easier. >>> >>> Great. Thanks ! >>> Are you taking both patches or should Plamer take the riscv Kconfig change >>> through his tree ? >> >> I am happy to take both. >> Palmer? > >Palmer, > >Ping ! I already Ack'd it, in the thread where we couldn't find the maintainer. Keeping these togther is fine with me, and it seems easiest. > > >-- >Damien Le Moal >Western Digital Research > _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-23 4:04 ` Palmer Dabbelt @ 2021-04-23 5:38 ` Greg Ungerer 2021-04-23 6:44 ` Palmer Dabbelt 0 siblings, 1 reply; 11+ messages in thread From: Greg Ungerer @ 2021-04-23 5:38 UTC (permalink / raw) To: Palmer Dabbelt, Damien Le Moal Cc: uclinux-dev, linux-riscv, linux-kernel, Anup Patel, Christoph Hellwig On 23/4/21 2:04 pm, Palmer Dabbelt wrote: > On Thu, 22 Apr 2021 05:00:32 PDT (-0700), Damien Le Moal wrote: >>> On 2021/04/18 11:38, Greg Ungerer wrote: >>> >>> >>> On 17/4/21 2:54 pm, Damien Le Moal wrote: >>>> On 2021/04/17 13:52, Greg Ungerer wrote: >>>>> >>>>> On 17/4/21 11:10 am, Damien Le Moal wrote: >>>>>> Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset >>>>>> the data start"") restored offsetting the start of the data section by >>>>>> a number of words defined by MAX_SHARED_LIBS. As a result, since >>>>>> MAX_SHARED_LIBS is never 0, a gap between the text and data sections >>>>>> always exists. For architectures which cannot support a such gap >>>>>> between the text and data sections (e.g. riscv nommu), flat binary >>>>>> programs cannot be executed. >>>>>> >>>>>> To allow an architecture to request no data start offset to allow for >>>>>> contiguous text and data sections for binaries flagged with >>>>>> FLAT_FLAG_RAM, introduce the new config option >>>>>> CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the >>>>>> macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c >>>>>> to MAX_SHARED_LIBS for architectures tolerating or needing the data >>>>>> start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) >>>>>> and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. >>>>>> DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the >>>>>> data section length and start position. >>>>>> >>>>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> >>>>>> --- >>>>>> fs/Kconfig.binfmt | 3 +++ >>>>>> fs/binfmt_flat.c | 19 ++++++++++++++----- >>>>>> 2 files changed, 17 insertions(+), 5 deletions(-) >>>>>> >>>>>> diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt >>>>>> index c6f1c8c1934e..06fb7a93a1bd 100644 >>>>>> --- a/fs/Kconfig.binfmt >>>>>> +++ b/fs/Kconfig.binfmt >>>>>> @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK >>>>>> config BINFMT_FLAT_OLD_ALWAYS_RAM >>>>>> bool >>>>>> +config BINFMT_FLAT_NO_DATA_START_OFFSET >>>>>> + bool >>>>>> + >>>>>> config BINFMT_FLAT_OLD >>>>>> bool "Enable support for very old legacy flat binaries" >>>>>> depends on BINFMT_FLAT >>>>>> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >>>>>> index b9c658e0548e..1dc68dfba3e0 100644 >>>>>> --- a/fs/binfmt_flat.c >>>>>> +++ b/fs/binfmt_flat.c >>>>>> @@ -74,6 +74,12 @@ >>>>>> #define MAX_SHARED_LIBS (1) >>>>>> #endif >>>>>> +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET >>>>>> +#define DATA_START_OFFSET_WORDS (0) >>>>>> +#else >>>>>> +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) >>>>>> +#endif >>>>>> + >>>>>> struct lib_info { >>>>>> struct { >>>>>> unsigned long start_code; /* Start of text segment */ >>>>>> @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>> * it all together. >>>>>> */ >>>>>> if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { >>>>>> + >>>>> >>>>> Random white space change... >>>>> Don't worry about re-spinning though, I will just edit this chunk out. >>>> >>>> Oops. Sorry about that. I should have better checked :) >>>> >>>>> >>>>> >>>>>> /* >>>>>> * this should give us a ROM ptr, but if it doesn't we don't >>>>>> * really care >>>>>> @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>> goto err; >>>>>> } >>>>>> - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); >>>>>> + len = data_len + extra + >>>>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long); >>>>>> len = PAGE_ALIGN(len); >>>>>> realdatastart = vm_mmap(NULL, 0, len, >>>>>> PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); >>>>>> @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>> goto err; >>>>>> } >>>>>> datapos = ALIGN(realdatastart + >>>>>> - MAX_SHARED_LIBS * sizeof(unsigned long), >>>>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long), >>>>>> FLAT_DATA_ALIGN); >>>>>> pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", >>>>>> @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>> memp_size = len; >>>>>> } else { >>>>>> - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); >>>>>> + len = text_len + data_len + extra + >>>>>> + DATA_START_OFFSET_WORDS * sizeof(u32); >>>>>> len = PAGE_ALIGN(len); >>>>>> textpos = vm_mmap(NULL, 0, len, >>>>>> PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); >>>>>> @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>> realdatastart = textpos + ntohl(hdr->data_start); >>>>>> datapos = ALIGN(realdatastart + >>>>>> - MAX_SHARED_LIBS * sizeof(u32), >>>>>> + DATA_START_OFFSET_WORDS * sizeof(u32), >>>>>> FLAT_DATA_ALIGN); >>>>>> reloc = (__be32 __user *) >>>>>> @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>> ret = result; >>>>>> pr_err("Unable to read code+data+bss, errno %d\n", ret); >>>>>> vm_munmap(textpos, text_len + data_len + extra + >>>>>> - MAX_SHARED_LIBS * sizeof(u32)); >>>>>> + DATA_START_OFFSET_WORDS * sizeof(u32)); >>>>>> goto err; >>>>>> } >>>>>> } >>>>>> >>>>> >>>>> Thanks, otherwise looks good. >>>>> >>>>> Acked-by: Greg Ungerer <gerg@linux-m68k.org> >>>>> >>>>> I will push this into my m68knommu tree, for-next branch. >>>>> I just carry the flat format changes in that tree now to make my life easier. >>>> >>>> Great. Thanks ! >>>> Are you taking both patches or should Plamer take the riscv Kconfig change >>>> through his tree ? >>> >>> I am happy to take both. >>> Palmer? >> >> Palmer, >> >> Ping ! > > I already Ack'd it, in the thread where we couldn't find the maintainer. Keeping these togther is fine with me, and it seems easiest. The 2/2 patch has been applied to the m68knommu git tree, for-next branch. Regards Greg _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v4 1/2] binfmt_flat: allow not offsetting data start 2021-04-23 5:38 ` Greg Ungerer @ 2021-04-23 6:44 ` Palmer Dabbelt 0 siblings, 0 replies; 11+ messages in thread From: Palmer Dabbelt @ 2021-04-23 6:44 UTC (permalink / raw) To: gerg Cc: Damien Le Moal, uclinux-dev, linux-riscv, linux-kernel, Anup Patel, Christoph Hellwig On Thu, 22 Apr 2021 22:38:36 PDT (-0700), gerg@linux-m68k.org wrote: > > > On 23/4/21 2:04 pm, Palmer Dabbelt wrote: >> On Thu, 22 Apr 2021 05:00:32 PDT (-0700), Damien Le Moal wrote: >>>> On 2021/04/18 11:38, Greg Ungerer wrote: >>>> >>>> >>>> On 17/4/21 2:54 pm, Damien Le Moal wrote: >>>>> On 2021/04/17 13:52, Greg Ungerer wrote: >>>>>> >>>>>> On 17/4/21 11:10 am, Damien Le Moal wrote: >>>>>>> Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset >>>>>>> the data start"") restored offsetting the start of the data section by >>>>>>> a number of words defined by MAX_SHARED_LIBS. As a result, since >>>>>>> MAX_SHARED_LIBS is never 0, a gap between the text and data sections >>>>>>> always exists. For architectures which cannot support a such gap >>>>>>> between the text and data sections (e.g. riscv nommu), flat binary >>>>>>> programs cannot be executed. >>>>>>> >>>>>>> To allow an architecture to request no data start offset to allow for >>>>>>> contiguous text and data sections for binaries flagged with >>>>>>> FLAT_FLAG_RAM, introduce the new config option >>>>>>> CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the >>>>>>> macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c >>>>>>> to MAX_SHARED_LIBS for architectures tolerating or needing the data >>>>>>> start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case) >>>>>>> and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled. >>>>>>> DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the >>>>>>> data section length and start position. >>>>>>> >>>>>>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> >>>>>>> --- >>>>>>> fs/Kconfig.binfmt | 3 +++ >>>>>>> fs/binfmt_flat.c | 19 ++++++++++++++----- >>>>>>> 2 files changed, 17 insertions(+), 5 deletions(-) >>>>>>> >>>>>>> diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt >>>>>>> index c6f1c8c1934e..06fb7a93a1bd 100644 >>>>>>> --- a/fs/Kconfig.binfmt >>>>>>> +++ b/fs/Kconfig.binfmt >>>>>>> @@ -112,6 +112,9 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK >>>>>>> config BINFMT_FLAT_OLD_ALWAYS_RAM >>>>>>> bool >>>>>>> +config BINFMT_FLAT_NO_DATA_START_OFFSET >>>>>>> + bool >>>>>>> + >>>>>>> config BINFMT_FLAT_OLD >>>>>>> bool "Enable support for very old legacy flat binaries" >>>>>>> depends on BINFMT_FLAT >>>>>>> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >>>>>>> index b9c658e0548e..1dc68dfba3e0 100644 >>>>>>> --- a/fs/binfmt_flat.c >>>>>>> +++ b/fs/binfmt_flat.c >>>>>>> @@ -74,6 +74,12 @@ >>>>>>> #define MAX_SHARED_LIBS (1) >>>>>>> #endif >>>>>>> +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET >>>>>>> +#define DATA_START_OFFSET_WORDS (0) >>>>>>> +#else >>>>>>> +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) >>>>>>> +#endif >>>>>>> + >>>>>>> struct lib_info { >>>>>>> struct { >>>>>>> unsigned long start_code; /* Start of text segment */ >>>>>>> @@ -560,6 +566,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>>> * it all together. >>>>>>> */ >>>>>>> if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { >>>>>>> + >>>>>> >>>>>> Random white space change... >>>>>> Don't worry about re-spinning though, I will just edit this chunk out. >>>>> >>>>> Oops. Sorry about that. I should have better checked :) >>>>> >>>>>> >>>>>> >>>>>>> /* >>>>>>> * this should give us a ROM ptr, but if it doesn't we don't >>>>>>> * really care >>>>>>> @@ -576,7 +583,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>>> goto err; >>>>>>> } >>>>>>> - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); >>>>>>> + len = data_len + extra + >>>>>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long); >>>>>>> len = PAGE_ALIGN(len); >>>>>>> realdatastart = vm_mmap(NULL, 0, len, >>>>>>> PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); >>>>>>> @@ -591,7 +599,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>>> goto err; >>>>>>> } >>>>>>> datapos = ALIGN(realdatastart + >>>>>>> - MAX_SHARED_LIBS * sizeof(unsigned long), >>>>>>> + DATA_START_OFFSET_WORDS * sizeof(unsigned long), >>>>>>> FLAT_DATA_ALIGN); >>>>>>> pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", >>>>>>> @@ -622,7 +630,8 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>>> memp_size = len; >>>>>>> } else { >>>>>>> - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); >>>>>>> + len = text_len + data_len + extra + >>>>>>> + DATA_START_OFFSET_WORDS * sizeof(u32); >>>>>>> len = PAGE_ALIGN(len); >>>>>>> textpos = vm_mmap(NULL, 0, len, >>>>>>> PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); >>>>>>> @@ -638,7 +647,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>>> realdatastart = textpos + ntohl(hdr->data_start); >>>>>>> datapos = ALIGN(realdatastart + >>>>>>> - MAX_SHARED_LIBS * sizeof(u32), >>>>>>> + DATA_START_OFFSET_WORDS * sizeof(u32), >>>>>>> FLAT_DATA_ALIGN); >>>>>>> reloc = (__be32 __user *) >>>>>>> @@ -714,7 +723,7 @@ static int load_flat_file(struct linux_binprm *bprm, >>>>>>> ret = result; >>>>>>> pr_err("Unable to read code+data+bss, errno %d\n", ret); >>>>>>> vm_munmap(textpos, text_len + data_len + extra + >>>>>>> - MAX_SHARED_LIBS * sizeof(u32)); >>>>>>> + DATA_START_OFFSET_WORDS * sizeof(u32)); >>>>>>> goto err; >>>>>>> } >>>>>>> } >>>>>>> >>>>>> >>>>>> Thanks, otherwise looks good. >>>>>> >>>>>> Acked-by: Greg Ungerer <gerg@linux-m68k.org> >>>>>> >>>>>> I will push this into my m68knommu tree, for-next branch. >>>>>> I just carry the flat format changes in that tree now to make my life easier. >>>>> >>>>> Great. Thanks ! >>>>> Are you taking both patches or should Plamer take the riscv Kconfig change >>>>> through his tree ? >>>> >>>> I am happy to take both. >>>> Palmer? >>> >>> Palmer, >>> >>> Ping ! >> >> I already Ack'd it, in the thread where we couldn't find the maintainer. Keeping these togther is fine with me, and it seems easiest. > > The 2/2 patch has been applied to the m68knommu git tree, for-next branch. Thanks! _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v4 2/2] riscv: Disable data start offset in flat binaries 2021-04-17 1:10 [PATCH v4 0/2] Fix binfmt_flat loader for RISC-V Damien Le Moal 2021-04-17 1:10 ` [PATCH v4 1/2] binfmt_flat: allow not offsetting data start Damien Le Moal @ 2021-04-17 1:10 ` Damien Le Moal 2021-04-17 4:56 ` Greg Ungerer 1 sibling, 1 reply; 11+ messages in thread From: Damien Le Moal @ 2021-04-17 1:10 UTC (permalink / raw) To: uclinux-dev, Greg Ungerer, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig uclibc/gcc combined with elf2flt riscv linker file fully resolve the PC relative __global_pointer$ value at compile time and do not generate a relocation entry to set a correct value of the gp register at runtime. As a result, if the flatbin loader offsets the start of the data section, the relative position change between the text and data sections compared to the compile time positions results in an incorrect gp value being used. This causes flatbin executables to crash. Avoid this problem by enabling CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET automatically when CONFIG_RISCV is enabled and CONFIG_MMU is disabled. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> --- arch/riscv/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4515a10c5d22..add528eb9235 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -33,6 +33,7 @@ config RISCV select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if 64BIT + select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU select CLONE_BACKWARDS select CLINT_TIMER if !MMU select COMMON_CLK -- 2.30.2 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH v4 2/2] riscv: Disable data start offset in flat binaries 2021-04-17 1:10 ` [PATCH v4 2/2] riscv: Disable data start offset in flat binaries Damien Le Moal @ 2021-04-17 4:56 ` Greg Ungerer 0 siblings, 0 replies; 11+ messages in thread From: Greg Ungerer @ 2021-04-17 4:56 UTC (permalink / raw) To: Damien Le Moal, uclinux-dev, Palmer Dabbelt, linux-riscv Cc: linux-kernel, Anup Patel, Christoph Hellwig On 17/4/21 11:10 am, Damien Le Moal wrote: > uclibc/gcc combined with elf2flt riscv linker file fully resolve the > PC relative __global_pointer$ value at compile time and do not generate > a relocation entry to set a correct value of the gp register at runtime. > As a result, if the flatbin loader offsets the start of the data > section, the relative position change between the text and data sections > compared to the compile time positions results in an incorrect gp value > being used. This causes flatbin executables to crash. > > Avoid this problem by enabling CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET > automatically when CONFIG_RISCV is enabled and CONFIG_MMU is disabled. > > Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> > Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Greg Ungerer <gerg@linux-m68k.org> Palmer do you want me to take this via my tree with 1/2 in the series, or are you going to pick it up? Regards Greg > --- > arch/riscv/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 4515a10c5d22..add528eb9235 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -33,6 +33,7 @@ config RISCV > select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU > select ARCH_WANT_FRAME_POINTERS > select ARCH_WANT_HUGE_PMD_SHARE if 64BIT > + select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU > select CLONE_BACKWARDS > select CLINT_TIMER if !MMU > select COMMON_CLK > _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2021-04-23 6:45 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-04-17 1:10 [PATCH v4 0/2] Fix binfmt_flat loader for RISC-V Damien Le Moal 2021-04-17 1:10 ` [PATCH v4 1/2] binfmt_flat: allow not offsetting data start Damien Le Moal 2021-04-17 4:52 ` Greg Ungerer 2021-04-17 4:54 ` Damien Le Moal 2021-04-18 2:38 ` Greg Ungerer 2021-04-22 12:00 ` Damien Le Moal 2021-04-23 4:04 ` Palmer Dabbelt 2021-04-23 5:38 ` Greg Ungerer 2021-04-23 6:44 ` Palmer Dabbelt 2021-04-17 1:10 ` [PATCH v4 2/2] riscv: Disable data start offset in flat binaries Damien Le Moal 2021-04-17 4:56 ` Greg Ungerer
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