From 436b47f678c2fc5397ed66a1eddf6b419cc6585b Mon Sep 17 00:00:00 2001 From: Josh Stone Date: Fri, 13 Mar 2009 16:22:04 -0700 Subject: Move lookup_bad_addr call in STAPCONF_PROBE_KERNEL With most of the implementations, kread/kwrite call deref/store_deref, and so it makes sense to have lookup_bad_addr in the latter as an underlying address check. However, in the STAPCONF_PROBE_KERNEL case that uses probe_kernel_read and probe_kernel_write, the roles are reversed, so lookup_bad_addr needs to be in kread/kwrite. Also note that __deref_bad and __store_deref_bad should only be used in cases that can be determined at compile time. These turn into invalid symbols which prevent the module from loading. (They might be better replaced with compile-time assertions.) --- runtime/loc2c-runtime.h | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'runtime/loc2c-runtime.h') diff --git a/runtime/loc2c-runtime.h b/runtime/loc2c-runtime.h index 0af19edc..92c017d3 100644 --- a/runtime/loc2c-runtime.h +++ b/runtime/loc2c-runtime.h @@ -187,22 +187,22 @@ #define kread(ptr) ({ \ typeof(*(ptr)) _v; \ - if (probe_kernel_read((void *)&_v, (void *)(ptr), sizeof(*(ptr)))) \ - DEREF_FAULT(ptr); \ + if (lookup_bad_addr((unsigned long)(ptr)) || \ + probe_kernel_read((void *)&_v, (void *)(ptr), sizeof(*(ptr)))) \ + DEREF_FAULT(ptr); \ _v; \ }) #define kwrite(ptr, value) ({ \ typeof(*(ptr)) _v; \ _v = (typeof(*(ptr)))(value); \ - if (probe_kernel_write((void *)(ptr), (void *)&_v, sizeof(*(ptr)))) \ - STORE_DEREF_FAULT(ptr); \ + if (lookup_bad_addr((unsigned long)addr) || \ + probe_kernel_write((void *)(ptr), (void *)&_v, sizeof(*(ptr)))) \ + STORE_DEREF_FAULT(ptr); \ }) #define deref(size, addr) ({ \ intptr_t _i; \ - if (lookup_bad_addr((unsigned long)addr)) \ - __deref_bad(); \ switch (size) { \ case 1: _i = kread((u8 *)(addr)); break; \ case 2: _i = kread((u16 *)(addr)); break; \ @@ -215,8 +215,6 @@ }) #define store_deref(size, addr, value) ({ \ - if (lookup_bad_addr((unsigned long)addr)) \ - __store_deref_bad(); \ switch (size) { \ case 1: kwrite((u8 *)(addr), (value)); break; \ case 2: kwrite((u16 *)(addr), (value)); break; \ -- cgit From 924a2ea21d0276229a752e58e5c5c1a9346648be Mon Sep 17 00:00:00 2001 From: Josh Stone Date: Mon, 16 Mar 2009 18:36:44 -0700 Subject: PR9951: Prevent GCC warnings in deref() In some configurations, GCC was warning about a possible use of _v in the deref macros. I could not reproduce the error, but the only case where _v is not written is if lookup_bad_addr rejects the address, in which case we will hit DEREF_FAULT and _v won't be used. Now we're priming _v=0 anyway, so GCC has no right to complain... --- runtime/loc2c-runtime.h | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'runtime/loc2c-runtime.h') diff --git a/runtime/loc2c-runtime.h b/runtime/loc2c-runtime.h index 92c017d3..16ddb950 100644 --- a/runtime/loc2c-runtime.h +++ b/runtime/loc2c-runtime.h @@ -186,7 +186,7 @@ */ #define kread(ptr) ({ \ - typeof(*(ptr)) _v; \ + typeof(*(ptr)) _v = 0; \ if (lookup_bad_addr((unsigned long)(ptr)) || \ probe_kernel_read((void *)&_v, (void *)(ptr), sizeof(*(ptr)))) \ DEREF_FAULT(ptr); \ @@ -202,14 +202,13 @@ }) #define deref(size, addr) ({ \ - intptr_t _i; \ + intptr_t _i = 0; \ switch (size) { \ case 1: _i = kread((u8 *)(addr)); break; \ case 2: _i = kread((u16 *)(addr)); break; \ case 4: _i = kread((u32 *)(addr)); break; \ case 8: _i = kread((u64 *)(addr)); break; \ default: __deref_bad(); \ - /* uninitialized _i should also be caught by -Werror */ \ } \ _i; \ }) @@ -235,7 +234,7 @@ extern void __store_deref_bad(void); ({ \ int _bad = 0; \ u8 _b; u16 _w; u32 _l; \ - intptr_t _v; \ + intptr_t _v = 0; \ if (lookup_bad_addr((unsigned long)addr)) \ _bad = 1; \ else \ @@ -275,7 +274,7 @@ extern void __store_deref_bad(void); ({ \ int _bad = 0; \ u8 _b; u16 _w; u32 _l; u64 _q; \ - intptr_t _v; \ + intptr_t _v = 0; \ if (lookup_bad_addr((unsigned long)addr)) \ _bad = 1; \ else \ @@ -392,7 +391,7 @@ extern void __store_deref_bad(void); #define deref(size, addr) \ ({ \ int _bad = 0; \ - intptr_t _v; \ + intptr_t _v = 0; \ if (lookup_bad_addr((unsigned long)addr)) \ _bad = 1; \ else \ -- cgit